Table of contents

Continuous monitoring and control of hydrocarbon flow is not a new task. Today, there are many engineering solutions in flow measurement that are used in commercial applications. However, the search for other solutions continues and is associated with the emergence of new technical challenges of the oil and gas industry. There is also a constant request for optimization of already working flow-metering solutions. In the present work we propose a methodology to calculate the composition of a mixture using gamma densitometry methods with direct and scattered radiation tracking. Experiments were carried out on reference samples and ways of practical implementation of the proposed methodology are shown.

This paper describes the small-diameter monitored drift-tube detector construction at the University of Michigan as a contribution to the ATLAS Muon Spectrometer upgrade for the high-luminosity Large Hadron Collider at CERN. Measurements of the first 30 chambers built at Michigan show that the drift tube wire position accuracy meets the specification of 20 μm. The positions of the platforms for alignment and magnetic field sensors are all installed well within the required precision. The cosmic ray test measurements show single wire tracking resolution of 100 ± 7 μm with an average detection efficiency above 99%. The infrastructure, tooling, techniques, and procedures for chamber production are described in detail. The results from the chamber quality control tests of the first 30 constructed chambers are reported.

We present a new instrument composed of a large number of sub-electron noise Skipper-CCDs operated with a two stage analog multiplexed readout scheme suitable for scaling to thousands of channels. New, thick, 1.35 Mpix sensors, from a new foundry, are glued into a Multi-Chip Module (MCM) printed circuit board on a ceramic substrate which has 16 sensors each. The instrument, that can hold up-to 16 MCMs, a total of 256 Skipper-CCD sensors (called a Super-Module with ≈ 130 grams of active mass and 346 Mpix), is part of the R&D effort of the OSCURA experiment which will have ≈ 94 super-modules. Experimental results with 10 MCMs and 160 Skipper-CCDs sensors are presented in this paper. This is already the largest ever built instrument with single electron sensitivity CCDs using nondestructive readout, both, in terms of active mass and number of channels.

The next generation of collider experiments require tracking detectors with extreme performance capabilities in terms of spatial resolution (tens of µm), radiation hardness (10¹⁷ 1 MeV n_eq/cm²) and timing resolution (tens of ps). 3D silicon sensors, recently developed within the TimeSPOT initiative, offer a viable solution to cope with such demanding requirements. In order to accurately characterize the timing performance of these new sensors, several read-out boards, based on discrete active components, have been designed, assembled, and tested. The same electronics is also suitable for characterization of similar pixel sensors whenever timing performance in the order and below 10 ps is a requirement. This paper describes the general characteristics needed by front-end electronics to exploit solid-state sensors with fast timing capabilities and in particular, showcases the performance of the developed electronics in the testing and characterization of fast 3D silicon sensors.

The first evaluation of an ultra-high granularity digital electromagnetic calorimeter prototype using 1.0–5.8 GeV/c electrons is presented. The 25 × 10⁶ pixel detector consists of 24 layers of ALPIDE CMOS MAPS sensors, with a pitch of around 30 μm, and has a depth of almost 20 radiation lengths of tungsten absorber. Ultra-thin cables allow for a very compact design. The properties that are critical for physics studies are measured: electromagnetic shower response, energy resolution and linearity. The stochastic energy resolution is comparable with the state-of-the art resolution for a Si-W calorimeter, with data described well by a simulation model using Geant4 and Allpix². The performance achieved makes this technology a good candidate for use in the ALICE FoCal upgrade, and in general demonstrates the strong potential for future applications in high-energy physics.

Large-area silicon photomultipliers (SiPMs) are desired in many applications where large surfaces have to be covered. For instance, a large area SiPM has been developed by Hamamatsu Photonics in collaboration with the University of Geneva, to equip gamma-ray cameras employed in imaging atmospheric Cherenkov telescopes. The sensor being about 1 cm², a suitable preamplification electronics has been investigated in this work, which can deal with long pulses induced by the large capacitance of the sensor. The so-called Multiple Use SiPM Integrated Circuit (MUSIC), developed by the ICCUB (University of Barcelona), is investigated as a potential front-end ASIC, suitable to cover large area photodetection planes of gamma-ray telescopes. The ASIC offers an interesting pole-zero cancellation (PZC) that allows dealing with long SiPM signals, the feature of active summation of up to 8 input channels into a single differential output and it can offer a solution for reducing power consumption compared to discrete solutions. Measurements and simulations of MUSIC coupled to two SiPMs developed by Hamamatsu are considered and the ASIC response is characterized.

Sensitivity to ultra-high-energy neutrinos (E > 17 eV) can be obtained cost-efficiently by exploiting the Askaryan effect in ice, where a particle cascade induced by the neutrino interaction produces coherent radio emission that can be picked up by antennas. As the near-surface ice properties change rapidly within the upper (100 m), a good understanding of the ice properties is required to reconstruct the neutrino properties. In particular, continuous monitoring of the snow accumulation (which changes the depth of the antennas) and the index-of-refraction n(z) profile are crucial for an accurate determination of the neutrino's direction and energy. We present an in-situ calibration system that extends the radio detector station with two radio emitters to continuously monitor the firn properties within the upper 40 m by measuring the time differences between direct and reflected (off the surface) signals (D'n'R). We determine the optimal positions of two transmitters at all three sites of current and future in-ice radio detectors: Greenland, Moore's Bay, and the South Pole. For the South Pole we find that the snow accumulation Δh can be measured with a resolution of 3 mm and the parameters of an exponential n(z) profile α and z₀ with 0.04% and 0.14% precision respectively, which constitutes an improvement of more than a factor of 10 as compared to the inference of the n(z) profile from density measurements. Additionally, as this technique is based on the measurement of the signal propagation times we are not bound to the conversion of density to index-of-refraction. We quantify the impact of these ice uncertainties on the reconstruction of the neutrino vertex, direction, and energy and find that the calibration device measures the ice properties to sufficient precision to have negligible influence.

In nuclear medicine, the development of portable imaging devices that provide high imaging resolution and sensitivity, capable of imaging gamma rays with a wide energy range and multiple radioisotopes tracing capabilities, is so important. These goals have been possible thanks to developing a compact Compton camera, a collimatorless detector coupled to compact silicon photomultiplier(SiPM) array, using scintillator crystal. In this study, the portable segmented GAGG:Ce scintillator-based Compton camera (CC) is optimized with the GATE, a Monte Carlo simulation toolkit based on Geant4, to maximize its performance for a wide range of gamma-ray energy (364–1000 keV). The geometrical parameters are selected as optimization parameters to investigate their effects on CC's performance, including imaging resolution and absolute detection efficiency (DE_a). The geometry parameters of CC include the planner area of scatterer and absorber detectors, their thicknesses, and the distance between them. The results for the energy range of 364–1000 keV show that the most important contributions to the spatial resolution and DE_a of the camera are SAD (scatterer to absorber distance) and the scatterer area while changing absorber area (A_A) showed the most negligible impact. In the short SADs, imaging resolution and DE_a are significantly affected by the detector's size and thickness. On the other hand, in the long SADs (> 4 cm), both spatial resolution and DE_a are significantly affected by the detector's area but less affected by the detector's thickness. Decreasing the scatterer's thickness and the absorber's size or thickness improves imaging resolution without significantly reducing DE_a. The simulation study's findings presented here will provide valuable guidelines for researchers choosing a desired CC's design according to particular objectives, manufacturing limitations in scintillator growth, cost, etc.

Cyclotron Radiation Emission Spectroscopy (CRES) is a technique for measuring the kinetic energy of charged particles through a precision measurement of the frequency of the cyclotron radiation generated by the particle's motion in a magnetic field. The Project 8 collaboration is developing a next-generation neutrino mass measurement experiment based on CRES. One approach is to use a phased antenna array, which surrounds a volume of tritium gas, to detect and measure the cyclotron radiation of the resulting β-decay electrons. To validate the feasibility of this method, Project 8 has designed a test stand to benchmark the performance of an antenna array at reconstructing signals that mimic those of genuine CRES events. To generate synthetic CRES events, a novel probe antenna has been developed, which emits radiation with characteristics similar to the cyclotron radiation produced by charged particles in magnetic fields. This paper outlines the design, construction, and characterization of this Synthetic Cyclotron Antenna (SYNCA). Furthermore, we perform a series of measurements that use the SYNCA to test the position reconstruction capabilities of the digital beamforming reconstruction technique. We find that the SYNCA produces radiation with characteristics closely matching those expected for cyclotron radiation and reproduces experimentally the phenomenology of digital beamforming simulations of true CRES signals.

The increase of neutron flux in pulsed spallation neutron facilities imposes demands on the neutron detector for beam monitoring, including excellent neutron/gamma discrimination, wide dynamic neutron-flux measurement range, wavelength resolution, and long-term stability. In this paper, we developed a ceramic GEM-based (gas electron multiplier) neutron detector with an active area of 100 mm × 100 mm. It adopted a thinner conversion material and the stopping layer to lower the detection efficiency so as to extend the dynamic measurement range of the detector. The detection efficiency of this detector was investigated by the Monte Carlo (MC) tool FLUKA, showing that the low efficiency around 0.01% for 1 Åneutrons was reached by using a 0.1 μm^natB₄C converter appended with an aluminum film of 2 μm thickness. Its validation of the wavelength spectra measurement was verified by comparisons with that made with an LND monitor, and it could work at the condition of 7.1 × 10⁹ n/s for 2.5 Åneutrons. In addition, it was demonstrated that this detector was able to measure the beam profile with a position resolution of better than 2.1 ± 0.1 mm. The results of simulations and experiments show that this ceramic-GEM neutron detector can meet the requirements of the direct measurement of high-flux beam, and it will be a new neutron detector for the beam monitoring at the China spallation neutron source (CSNS).

Silicon and diamond are regarded as promising solid-state detectors for microdosimetry and have attracted considerable attention in recent years. However, their performance is slightly different due to the difference in physical qualities. In this work, we intend to compare their performance in microdosimetry theoretically from the aspect of tissue equivalence and electronic properties. The tissue equivalence study has shown that diamond exhibits better tissue equivalence than silicon due to the approximation of mean ionization/excitation potential to tissue. And the tissue equivalence of silicon is acceptable when the incident energy is low. In electronic properties comparison, the results indicate that the collection time in the diamond is shorter than that in silicon when aligned in the same configuration, and the current signal induced in CVD diamond is higher than in silicon at low electric fields. The current in natural diamond is greater than silicon at the low electric field only when the energy deposited in silicon and diamond is different. Since the microdosimeter is usually performed at low electric fields in microdosimetry to ensure low electronic noise, the electronic properties of high-quality CVD diamond are superior to silicon for microdosimetry applications. It seems that diamond, especially high-quality CVD diamond, exhibits better tissue equivalence and electronic properties than silicon in microdosimetry.

Radiation portal monitors comprising large-volume plastic scintillators are commonly used to monitor the smuggling of radioactive materials. Various applications have been proposed to perform radioisotope identification using these monitors. Such applications require calibration of the spectrum measured by the detector to obtain the physical energy spectrum. The relationship between the multichannel readout and energy bins depends on environmental conditions: it implies that energy calibration in radiation portal monitors should be performed periodically, even multiple times in a single day, thus demanding for a simple and fast energy calibration method. In this study, a deep learning model and a spectral remapping method were used to transform the raw detector output into an energy spectrum with constant energy bins. The deep learning model was designed to predict energy calibration parameters based on the channel spectrum of a single radioisotope. The dataset used to train the deep learning model was generated using the spectrum of the radiation portal monitor. A convolutional neural network model was utilized to evaluate the performance. The remapping method was designed to remap calibrated energy bins to fixed energy bins based on the linear interpolation of nearby bins. The performance of the neural network model and of the remapping method were then evaluated based on several measured spectra taken with different conditions, and found to be adequate to fulfill the requirements.

We have developed a γ-ray computed tomography system using a CdTe double-sided strip detector. Owing to a 250 μm fine strip pitch and high energy resolution with photon-counting capability, the system provides highly accurate images, with which the materials and their distributions inside the target can be determined according to the photon transmittances. We evaluated the key performance of the system, conducting transmission measurements for Al, Cu, and Pb plates and also for Al, Fe, Cu, and Pb rod-phantoms, both using X-rays (∼30 keV) and γ-rays (∼80 keV) from a ¹³³Ba source. The measured transmittances agreed well with the calculated values from simulations. We successfully reconstructed the three-dimensional structure of the rod-phantom and distinguished the elements inside the phantom. Compared with the simulated photon transmittances, we found that material identification based on tomographic images obtained with the system is efficient as long as the target object does not contain thick high-Z elements.

Detection of the vacuum ultraviolet (VUV) scintillation light produced by liquid noble elements is a central challenge in order to fully exploit the available timing, topological, and calorimetric information in detectors leveraging these media. In this paper, we characterize a novel, windowless amorphous selenium based photodetector with direct sensitivity to VUV light. We present here the manufacturing and experimental setup used to operate this detector at low transport electric fields (2.7–5.2 V/μm) and across a wide range of temperatures (77 K–290 K). This work shows that the first proof-of-principle windowless amorphous selenium device is robust under cryogenic conditions, responsive to VUV light at cryogenic temperatures, and preserves argon purity. These findings motivate a continued exploration of amorphous selenium devices for simultaneous detection of scintillation light and ionization charge in noble element detectors.

In modern particle accelerators with ultra-low emittance, the vacuum chambers are designed based on Non-Evaporable Getter (NEG)-coated vacuum chambers. The thickness of the NEG coating plays a critical role in the dynamic beam effects. So, in this paper, the longitudinal and transverse impedance of a copper chamber coated with a NEG are investigated, and the effects of the NEG thickness over a wide range of frequencies have been studied. A good selection of NEG layer thickness could minimize the coating effects on the longitudinal and transverse beam impedance. The numerical results in this work show that the beam dynamic effects could be minimal with selecting a NEG coating thickness of about 1 μm.

Commercial alpha counters are used in science and industry applications to screen materials for surface radon progeny contamination. In this paper, we characterize an XIA UltraLo-1800, an ionization drift alpha counter, and study the response to embedded charge in polyethylene sample measurements. We show that modeling such effects is possible in a Geant4-based simulation framework and attempt to derive corrections. This paper also demonstrates the effectiveness of the use of an anti-static fan to eliminate the embedded charge and recover a 97.73% alpha detection efficiency in the alpha counter.

The research work of Hefei Advanced Light Facility (HALF) is in progress. A 499.8 MHz superconducting cavity will be used in the HALF RF system. The preliminary RF design and thermal analysis for the fundamental power coupler (FPC) of HALF 499.8 MHz superconducting cavity have been completed. Multipacting (MP) is one of the major causes of the breakdown in many high power input couplers and RF cavities, thus, MP simulation for our FPC is necessary. In this paper, the MP simulation for the FPC was performed by using the CST. The MP performance of the FPC was studied. The formation process of the MP in the FPC was investigated and the physical mechanism of the delay of the MP establishment was analyzed. The simulation results show that MP will occur when the power level is higher than 175 kW, and the MP location is near the ceramic. Therefore, MP suppression is required in the FPC. In order to suppress the MP, the effect of the biasing DC electric voltage to MP in the FPC was analyzed in this paper. The simulation results indicates that the biasing DC electric voltage not only can suppress the MP, but also can excites new MP in the coupler. Thus, it is crucial to select the appropriate biasing DC electric voltage for the MP suppression in the coupler. The results show that the MP in the FPC can be suppressed very well by using 2 kV or 3 kV biasing DC electric voltage.

In the EAST experiment, the extent of damages of the divertor is different in toroidal direction. One of the reasons is uneven of heat load of toroidal distribution, which may be caused by geometric errors of the divertor surface. The EAST lower divertor is cooled by 8 toroidal active water-cooling branches, and calorimetric system estimates the heat load and its distribution by measuring the cooling water temperature difference and flow rate. The non-uniformity of the heat load of 8 branches is -3.5% ∼ 4.5%. Besides, using the Leica AT960 / AT401 laser tracker to measure the profile deviation of the upgraded lower divertor, the non-uniformity of the geometric accuracy is -15% ∼ 25%. Besides, it's found that the annular heat load distribution is positively correlated with the comprehensive deviation of the divertor surface. The correlation coefficient is about 15%, and at least seven of the eight divertor regions meet this characteristic.

A transition-radiation detector (TRD) is a powerful device for highly relativistic electron (γ ≳ 1,000) identification. Electron identification is crucial for tagging the outgoing scattered electrons in an electron-ion collider (EIC) detector. Employing a TRD at the electron forward region of an EIC detector can provide the necessary electron identification with high hadron rejection over a wide momentum range. Thick gas electron multiplier (THGEM) technology is suitable for radiation detection in modern high-energy experiments owing to its high-granularity structure, radiation hardness, high-rate capability and ease of large-area production. This study investigates a TRD prototype based on THGEM technology through soft X-ray and electron beam experiments. Geant4 simulation were extensively exploited to understand the operation of TRD prototype with different gas mixtures. Particularly, the performance of TRD prototype with an electron beam at the DESY, with argon-based gas rather than xenon-based gas, agreed well with the simulation analyses in all important aspects. Based on the consistency of the experimental and simulation results, a likelihood analysis on the simulated total energy deposit in the xenon-based working gas would suggest a pion rejection improvement with the optimization of detector design, readout electronics and identification algorithm.

Photoplethysmography (PPG) is a non-invasive technology and widely used in medical monitoring. Nowadays, dynamic vital signs monitoring based on PPG technology is in emergence and shows great potential for commercialization, however, it is still challenged by massive noise evoked by respiration and muscle contraction. Herein, a portable PPG signal's dynamic acquisition and denoise system is constructed and applied to blood pressure (BP) estimation, in which an improved PPG denoise method based on complete ensemble empirical mode decomposition with adaptive noise and wavelet transform (CEEMDAN-WT), is described. Firstly, original PPG signal is measured by the proposed hardware, then CEEMDAN decomposes it into a group of components. Secondly, the noise dominated components are found by calculating the coefficients between the components and original signal, and removed by WT. Thirdly, fast Fourier transform is performed to remove the component whose dominant frequency exceeds 0.5–20 Hz. Fourthly, a fresh PPG signal is reconstructed and compared with the signal rebuilt by other methods, which proves that CEEMDAN-WT has higher signal-to-noise ratio and lower root mean square error. Last but not least, the reconstructed signal is applied to estimate systolic and diastolic BP, according to Windkessel model and aided by neural network algorithm. Overall, this work demonstrates the feasibility of the portable PPG dynamic acquisition and its application for dynamic vital signs monitoring, in which CEEMDAN-WT algorithm can effectively remove most of the noises in dynamic PPG signal. In conclusion, it demonstrates CEEMDAN-WT method can effectively remove noise from PPG signals in the state of motion, it may have a good potential for calculating other physiological indexes besides BP, and push PPG applications from professional medical to daily life.

Fusion product diagnostics based on four commercially available single-crystal chemical vapor deposition (s-CVD) diamond detectors are installed in the Large Helical Device (LHD) in order to understand energetic ion confinement. Characteristics of s-CVD diamonds were surveyed using alpha and D-T neutron sources. It is found that the energy resolutions of s-CVD diamonds for ∼ 5 MeV alpha particles and 14 MeV neutrons are 1%–3% and ∼ 1.7%, respectively. Moreover, the response of four s-CVD diamond detectors to alpha particles and D-T neutrons is almost identical. The installation positions of the diamond detectors in the vacuum vessel are searched for, based on the loss points of charged fusion products reckoned by Lorentz orbit calculations. Energy- and time-resolved measurement of fusion product flux will progress in further understanding of energetic ion confinement in LHD.

In this work, a one-dimensional convolutional neural network (1D-CNN) is used for performing pulse shape discrimination (PSD) between the neutrons and gamma rays detected by the Cs₂LiYCl₆: Ce³⁺(CLYC) crystal. We use three different optimizers to train the CNN for comparing the effects of different optimizers on the training results. The neural network that uses the RMSProp optimizer performed the best. The accuracy of the AmBe source reaches 99.395%, and the false alarm rates (FARs) of the gamma source, i.e., ¹³⁷Cs and ²²Na are only 0.003% and 0.020%, separately. By the same dataset, we introduced several other methods to compare, including the classic charge integral (CI), partial charge-to-peak ratio (PCPR), decision tree (DT), support vector machine (SVM), K-nearest neighbor (KNN), and artificial neural network (ANN). Among these introduced methods, the FARs of the ANN method are better, which are 0.004% and 0.031%; however, its error is higher than that of the CNN method. A detailed discussion of the discrimination capability as a function of the sampling rate of the digitizer is also presented. We compare the performance of the CNN method and the traditional integral method under different sampling rates. The results show that even under a low sampling rate, the discrimination of the CNN method is almost unchanged, while the accuracy of the traditional integral method deteriorates rapidly. In addition, the CNN method is used for classifying more complicated particles, neutrons, gamma-rays, noise, and pile-up waveforms. The classification results show that the CNN has the ability to separate the four signals from the dataset efficiently.

The continued advancements of Silicon Photomultipliers (SiPMs) have made them viable photosensors for low recoil energy Pulse Shape Discrimination (PSD) between fast neutron and gamma interactions when coupled to an appropriate scintillator. At the same time, the large number of channels in a typical array calls for the development of low-cost and low-power electronics. A custom integrated circuit (ASIC) is an ideal solution for this purpose. To assess the requirements for such an ASIC, studies were performed using two scintillators, Stilbene and EJ-276, coupled to a 6 × 6 mm SiPM from Onsemi. We demonstrate that both scintillators are viable for performing PSD for interaction energies from 100 keV to several MeV while optimizing the integration periods used in the PSD metric. These measurements inform the design parameters of the ASIC under development.

In this paper, the smaller plastic scintillator (polystyrene as solvent) tiles are polymerized and shaped by two methods, i.e. injection molding technology and thermal pressing technology by domestic manufacturer, to be operated for more than 10 years in the hadron calorimeter of the Circular Electron Position Collider (CEPC) or other purposes. Other benefits include, researching aging problems, by adding 0.1% material antioxidants of 2,6-Di-tert-butyl-4-methylphenol (BHT) and without BHT, and according to Van't Hoff rule of equivalent chemical reaction rate of high temperature, the 10 years aging study is simulated in short term. A strobed coincidence setup is arranged to test the light yield of the tile to be measured with silicon photomultipliers (SiPMs) with ADC read out and a simple trigger system with small solid angle acceptance is adopted. The light yields of measured tiles without BHT decrease by about 26.6% (injection molding technology) and 43.3% (thermal polymerization technology) after ten-year equivalent aging time. Meanwhile, the light yields of the tiles with BHT almost did not change after ten-year equivalent aging time.

A repetitive low jitter trigger source applied in triggering the multi-gap gas switch of the linear transformer driver (LTD) stage, is designed and developed in this paper.The pulse source based on fast Marx topology can repetitively output a low jitter high voltage pulse into a 50 Ω resistance load with peak value of 150 kV, rising time of 7 ns, width of 260 ns and rep-rate 0.1 Hz. Proper design of stray capacitance to peak the output pulse and employing the UV light to pre-ionize each consequent stage gap to reduce the switch delay time and jitter have been proposed. All those have been demonstrated feasible and reliable. A software program control unit has been developed for operation and control of fast Marx generator. The software gives full remote control by a computer via optical fiber communication. The experimental results show that the trigger source can continuously and reliably generate a 150 kV/260 ns pulse into a resistive load every 10 s with 1-σ jitter less than 2.7 ns. The trigger source is compact and portable and agrees well with the trigger demands of LTD for new fusion energy.

CLYC (Ce) crystal is a new type of inorganic scintillator with excellent performance, which can realize neutron and gamma dual mode measurement. CLYC (Ce) detector is widely used in national defense, homeland security, nuclear imaging, environmental monitoring, nuclear medicine and other fields. The detection efficiency of the detector is an important index in the design and development of the detector. The detection model of CLYC (Ce) detector is established by using Geant4 program based on Monte Carlo method, and the factors affecting the detection efficiency of detector are studied. The results show that: the detection efficiency is related to the shape and size of crystal section. The detection efficiency of rectangular section is lower than that of circular and square section, and the larger the crystal radial size and length, the higher the detection efficiency. The detection efficiency of CLYC (Ce) detector is related to the energy of rays: the higher the energy of neutrons and gamma rays are, the lower the detection efficiency is. It indicates that the crystal responds better to thermal neutrons and low-energy gamma rays. At the same time, if the radiation source is emanative, the smaller the distance between the radiation source and the detector, the higher the detection efficiency of the scintillator.

An array of small-area Silicon Drift Detectors (SDD), named Hera, has been developed at Brookhaven National Laboratory (BNL) in the past few years. Its primary application is high-rate spectroscopy at synchrotrons. Each SDD pixel is a 1 mm × 1 mm square to match the footprint of the original diode-based pixel detector called Maia, which was developed for the same application. The replacement of the diode with an SDD allows for better energy resolution at short shaping times and an increased stability of the detector. 32, 96, and 384-channel arrays were designed and fabricated and achieved a Full Width Half Maximum (FWHM) as low as 176 eV at 5.9 keV with peaking time of 1 μs at -13°C. The sensor design, simulation, fabrication, its readout system, and its spectroscopic performance are reported.

In this paper, a robust pulse shape discrimination algorithm is proposed to classify neutron and gamma pulses in radiation detectors. Scalogram of the induced pulses, which represent the absolute value of the Continuous Wavelet Transform (CWT) coefficients in the time-frequency domain, is used as feature descriptors. A two-dimensional principal component analysis (2D PCA) is employed to achieve dimensionality reduction of the obtained features and remove the redundancy in the given data. Accordingly, dominant features are selected and stacked together to construct two feature sets representing the two classes (neutron and gamma). Canonical Correlation Analysis is performed between the testing and training feature sets to find the basis vectors on which the new projected set pairs are highly correlated. Experimental results showed that the proposed method outperforms the other state-of-the art PSD methods in terms the discrimination accuracy.

Preparing experiments that utilize free electron lasers is challenging because obtaining access to the facility is difficult. The integration of detectors into the data acquisition system needs to be tested before the beamtime starts. In this study, we develop a test signal generator that simulates the signals from a delay-line detector used in a time-of-flight electron spectrometer. The output signals of the simulator are connected to the time-to-digital converter electronics and simulate a realistic energy spectrum of a real spectrometer. Through this method, the detector electronics can be tested and integrated into the data acquisition system at the free electron laser before the actual instrument is available on site. In addition, the saturation behavior of the signal processing chain can be tested by changing the number of simulated electrons per pulse.

A new type of beam loss monitor has been developed based on the detection of fast neutrons produced by beam losses in hadron linear accelerators. This neutron sensitive Beam Loss Monitor (nBLM) has been concieved to fulfil the requirements of the European Spallation Source (ESS) and it will be part of the ESS neutron sensitive BLM system (ESS-nBLM). It has been specifically designed for the low energy part, where only neutrons and gammas produced by the loss can exit the accelerator vessel. Here other types of BLM, based on charged particle detection, suffer from the lack of signal compared to the photon background induced by the radio-frequency cavities. However, it can also be operated in regions of higher energy. The detector is of the Micromegas type and have been designed at IRFU to be able to detect fast neutrons while having a small sensitivity to gammas and thermal neutrons. In this work we focus on the proof of neutron-to-gamma rejection and the first operation of the detector in real beam conditions during the commissioning of LINAC4 (CERN). Controlled beam losses were provoked and have been detected by the nBLM detector installed, demonstrating also the discrimination of the neutron signal from RF x-ray background.

The SuperFGD detector will be a novel and important upgrade to the ND280 near detector for both the T2K and Hyper-Kamiokande projects. The main goal of the ND280 upgrade is to reduce systematic uncertainties associated with neutrino flux and cross-section modeling for future studies of neutrino oscillations using the T2K and Hyper-Kamiokande experiments. The upgraded ND280 detector will be able to perform a full exclusive reconstruction of the final state from neutrino-nucleus interactions, including measurements of low momentum protons, pions and for the first time, event-by event measurements of neutron kinematics. Precisely understanding the time resolution is critical for the neutron energy measurements and hence an important factor in reducing the systematic uncertainties. In this paper we present the results of time resolution measurements made with the SuperFGD prototype that consists of 9216 plastic scintillator cubes (cube size is 1 cm³) readout with 1728 wavelength-shifting (WLS) fibers along the three orthogonal directions. We used data from a muon beam exposure at CERN. A time resolution of 0.97 ns was obtained for one readout channel after implementing the time calibration with a correction for time-walk effects. The time resolution improves with increasing energy deposited in a scintillator cube, improving to 0.87 ns for large pulses. Averaging two readout channels for one scintillator cube further improves the time resolution to 0.68 ns implying that signals in different channels are not synchronous. In addition the contribution from the time sampling interval of 2.5 ns is averaged as well. Most importantly, averaging time values from N channels improves the time resolution by ∼ 1/√(N). For example, averaging the time from 2 scintillator cubes with 2 fibers each improves the time resolution to 0.47 ns which is much better than the intrinsic electronics time resolution of 0.72 ns in one channel due to the 2.5 ns sampling window. This indicates that a very good time resolution should be achievable for neutrons since neutron recoils typically interact with several scintillator cubes and in addition produce larger signal amplitudes than muons. Measurements performed with a laser and a wide-bandwidth oscilloscope in which the contribution from the electronics time sampling window was removed demonstrated that the time resolution obtained with the muon beam is not far from the theoretical limit. The intrinsic time resolution of a scintillator cube and one WLS fiber is about 0.67 ns for signals of 56 photo electrons which is typical for minimum ionizing particles.

2D and 4D transverse phase-space of a low-energy ion-beam is measured with two of the most common emittance scanners. The article covers the description of the installation, the setup, the settings, the experiment and the benchmark of the two emittance meters. We compare the results from three series of measurements and present the advantages and drawbacks of the two systems. Coupling between phase-space planes, correlations and mitigation of deleterious effects are discussed. The influence of background noise and aberrations of trace-space figures on emittance measurements and RMS calculations is highlighted, especially for low density beams and halos. A new data analysis method using noise reduction, filtering, and reconstruction of the emittance figure is described. Finally, some basic concepts of phase-space theory and application to beam transport are recalled.

A new method of power feedback control for the lower hybrid wave (LHW) systems on the experimental advanced superconducting tokamak (EAST) is presented. Different methods are applied to control the power of two LHW systems with different frequency at 2.45 GHz and at 4.6 GHz, respectively. The old method is applied to control the 4.6 GHz LHW power through the exciter of klystrons, and the new one is used to control the 2.45 GHz LHW power through the high voltage power supply (HVPS) system. The new method has been applied in EAST and successfully assisted the development of relevant experiments such as loop voltage control, q profile control.

Compressed Baryonic Matter (CBM) is a fixed target experiment at the upcoming Facility for Anti-proton and Ion Research in Germany, having collision rates up to 10 MHz. Due to the proximity of the target and secondaries produced in absorbers, Muon Chambers (MuCh) of the CBM experiment will face a very high particle hit rate of up to 400 kHz/cm² in its first two stations. To cope with these particle rates, a Gas Electron Multiplier (GEM) detector will be used for the first two stations while, due to relatively lower particle rates, the last two stations will use a low resistivity Bakelite Resistive Plate Chamber (RPC) detector. The electronics of these two MuCh detectors need different dynamic ranges. A Silicon Tracking Station (STS) system made of 300 μm thick silicon micro-strip sensors will be installed upstream of the MuCh detector system. The sensors will be read out through multi-line micro-cables with fast electronics. The micro-strip sensors will be double-sided with a stereo angle of 7.5°, a strip width of 58 μm, and strip lengths between 20 and 120 mm requiring high-density readout. To meet the high rate and high density requirements of MuCh and STS, respectively, a specialized 128-channel readout ASIC with a dual-gain feature is designed. This is a highly configurable ASIC with about 30,000 configurable register bits which control various bias and threshold settings of the ASIC. To integrate this ASIC with both the detector systems, detailed testing and characterization of the ASIC are required. Due to the high number of configurable registers and several operating conditions, characterizing this ASIC is very challenging. This paper describes the optimization procedures of several configurable bias parameters in detail and also explains how this ASIC is integrated with both GEM and RPC detectors of the MuCh system.

A heavy ion beam probe (HIBP) is being developed and tested on the HL-2A tokamak. To focus on the turbulence measurement in high beta scenarios with the toroidal magnetic field of 1.35 T, a 500 kV thallium beam is chosen and optimized. The locations of the injection and detection system are determined based on the probing beam trajectory calculations. The status of the accelerator, sweep system, analyzer, and control system is described. Four pairs of sweep plates are positioned in both primary and secondary beamlines to actively control the beam trajectory, where the poloidal sweepers require a maximum of 15 kV voltages to be applied. A parallel-plate energy analyzer with multi-slits is supplied by 100 kV high voltage for the electric potential measurement. The signal intensity is also evaluated to be hundreds of nA levels, 5 × 10⁷ V/A amplifiers are therefore designed. Software is also developed to include the data acquisition as well as the control and monitoring of HIBP subsystems.

On scintillator detectors, neutron and gamma rays could generate signals. These signals are generated internally and cannot be shielded, and there are various complex circumstances during data collection, such as piled-up pulse at high count rates and overflowed pulse caused by detector range limits. It is challenging to screen these complex circumstances using conventional methods like charge comparison. Conventional methods have low accuracy and lack self adaptability, to address these problem, a neural network based on residual connection structure (ResNet) was proposed. On the basis of the collected real signal, the pulse waveforms under complex circumstances were simulated. After integrating these waveforms into a dataset, they were trained and validated by ResNet and compared with two neural network algorithms MLP and CNN. The false predictions number of ResNet is 60% and 73% lower than that of CNN and MLP. The macro average F1 score of ResNet was 0.9956, which was significantly higher than 0.9885 of CNN and 0.9855 of MLP. And in the ROC and AUC, ResNet is still the best performing method, furthermore the improvement of ResNet to CNN is higher than that of CNN to MLP. These results indicated that Proposed ResNet is more suitable for neutron-gamma events discrimination in complex situations.

Imaging distributions of radioactive sources plays a substantial role in nuclear medicine as well as in monitoring nuclear waste and its deposit. Coded Aperture Imaging (CAI) has been proposed as an alternative to parallel or pinhole collimators, but requires image reconstruction as an extra step. Multiple reconstruction methods with varying run time and computational complexity have been proposed. Yet, no quantitative comparison between the different reconstruction methods has been carried out so far. This paper focuses on a comparison based on three sets of hot-rod phantom images captured with an experimental γ-camera consisting of a Tungsten-based MURA mask with a 2 mm thick 256 × 256 pixelated CdTe semiconductor detector coupled to a Timepix^© readout circuit. Analytical reconstruction methods, MURA Decoding, Wiener Filter and a convolutional Maximum Likelihood Expectation Maximization (MLEM) algorithm were compared to data-driven Convolutional Encoder-Decoder (CED) approaches. The comparison is based on the contrast-to-noise ratio as it has been previously used to assess reconstruction quality. For the given set-up, MURA Decoding, the most commonly used CAI reconstruction method, provides robust reconstructions despite the assumption of a linear model. For single image reconstruction, however, MLEM performed best of all analytical reconstruction methods, but took on average 45 times longer than MURA Decoding. The fastest reconstruction method is the Wiener Filter with a run time 4.3 times faster compared to MURA Decoding and a mediocre quality. The CED with a specifically tailored training set was able to succeed the most commonly used MURA decoding on average by a factor between 1.37 and 2.60 and an equal run time.

In intracavitary radiotherapy, it is essential to verify the correct location of radiation source among quality control items because an incorrect location will irradiate an unnecessary dose to normal tissues. As a basic study of digital line dosimeters, this study fabricated a unit cell dosimeter based on polycrystalline mercury (II) iodide (HgI₂) and compared its performance with a diode. The study result showed that for reproducibility, the relative standard deviation (RSD) was 1.21%, satisfying the RSD evaluation criterion of within 1.5%. Considering linearity, the coefficient of determination R² showed an excellent result of 0.9997. Regarding the evaluation of distance dependence, it showed a similar trend in general with a difference of 0.035 cm for intensity 50% when compared with the inverse square value. The angular dependence gradually decreased in intensity as the angle increased, showing a difference of up to 25%. This study suggests the applicability of a digital dosimeter for brachytherapy quality control by evaluating the performance of the HgI₂ dosimeter. However, to develop it into a quality assurance (QA) dosimeter, correction factor for sensitivity according to angle should be applied. This study on dosimeter for candidate photoconductor materials can be used as basic data in all areas using radiation.

We detail the design of a variable energy, x-ray fluorescence source using a low activity (1.8×10⁶ dpm) ⁹⁹Tc β source that irradiates thin foils. By rotating the source among foils of Ti, Zn, Nb, Ag, and Au, the device produces x rays between 4 and 70 keV at a rate near 1 Hz. When the source is placed in a storage position, the external radiation is non-detectable. The design of the shielding and rotation mechanism permits use in vacuum and at liquid nitrogen temperature. The design is intended for the study of the low energy response to radiation impinging upon Ge detector surfaces. The source will be useful for understanding the detector response in large-scale Ge arrays such as Majorana and LEGEND.

We examined the response of the pixel detector Timepix3 with silicon sensor to well-defined fast neutron fields. Part of the pixel detector silicon sensor was additionally equipped with a neutron mask of distinct converter regions. The mask consists of separate thermal and fast neutron regions using ⁶LiF and hydrogen (plastic) converters, respectively. Measurements were performed with mono-energetic fast neutrons produced at D-D and D-T sources from a Van de Graaff accelerator and a neutron generator, respectively. Data were collected with low background including measurements with moderator material to provide a thermalized neutron component. All the signals produced in the detector were analyzed and decomposed in terms of the spectral-tracking response of the pixel detector. The effect of the fast and thermal components of the neutron converter were determined and compared with direct interactions in the silicon sensor which are significant and can be dominant for fast neutrons. We identify and classify the neutron-induced tracks in terms of the broad-type particle-event track classes. A partial overlap is unavoidable with tracks from direct detection of other radiations in particular protons and low-energy light ions as well as X rays. This will limit the neutron-event discrimination in mixed-radiation fields. The detection response according sensor-mask region was examined and calibrated for the investigated neutron fields. The neutron detection efficiency is selectively derived for the detector particle-event classes. This approach enables to enhance the neutron-discrimination and suppress background and unwanted events. This work enables to extend the response matrix of the detector for broad-type radiations to include neutrons both fast and thermal. The results serve to enhance the sensitivity and determine the neutron component in unknown and mixed-radiation fields such as outer space and particle radiotherapy environments.

This paper proposes an efficient low cost mechanism to accurately measure the dielectric dissipation factor and its allied effect over resin impregnated paper. The measuring circuit is a modified De Sauty bridge network where the accurate parameter measurement can been performed. The effect of stray capacitance over dielectric loss and dissipation factor has been nullified by the application of operational amplifier in the circuit. Different samples of resin impregnated paper have been tested based on their aging and moisture content to check the reliability of the proposed measuring technique. Experimental result shows the efficacy of the proposed method when compared to existing IEC and ASTM standard procedures and commercial measuring devices. Measurement error analysis with repeatability and uncertainty calculation shows promising result and is within the acceptable limits.

A glass gas electron multiplier (GEM) was tested to evaluate performance for charged particle spectroscopy in a gas chamber. The test was done with varying low-pressure Ar/CH₄ mixture gas (9:1, P-10) for evaluation of effective electron multiplication gain (gas gain) with the relationship between supplied voltage to GEM (GEM ΔV), energy and timing resolution of signals. The GEM ΔV is parameterized as a function of gas gain and pressure from experimental results. The signal-to-noise ratio on the anode signal was significantly improved due to electron multiplication by the glass GEM in comparison with traditional grid gas ionization chamber. A test using Ar/CO₂ mixture gas (9:1) shows that GEM ΔV is successfully reduced with keeping gas gain and energy resolution comparable. Time difference between anode and cathode signals behaves reasonably with drift time of initial electrons. We conclude that charged particle spectrometer using glass GEM can be designed by using obtained parameter. The spectrometer is useful especially for low energy charged particle due to the gas gain.

Single-photon detection of X-rays in the energy range of 250 eV to 1 keV is difficult for hybrid detectors because of the low quantum efficiency and low signal-to-noise ratio. The low quantum efficiency is caused by the absorption of soft X-rays in the entrance window of the silicon sensors. The entrance window consists of an insensitive layer on the surface and a highly doped layer, which is typically from a few hundred nanometers to a couple of micrometers thick and is comparable to the absorption depth of soft X-ray photons (e.g. the attenuation length of 250 eV X-ray photons is ∼100 nm in silicon). The low signal-to-noise ratio is mainly caused by the small signal amplitude (e.g. ca. 70 electrons for 250 eV X-ray photons in silicon) with respect to the electronic noise. To improve the quantum efficiency, the entrance window must be optimized by minimizing the absorption of soft X-rays in the insensitive layer, and reducing charge recombination at the Si-SiO₂ interface and in the highly doped region. Low gain avalanche diodes (LGADs) with a multiplication factor between 5 and 10 increase the signal amplitude and therefore improve the signal-to-noise ratio for soft X-rays, enabling single-photon detection down to 250 eV. Combining LGAD technology with an optimized entrance window technology can thus allow hybrid detectors to become a useful tool also for soft X-ray detection. In this work we present the optimization of the entrance window by studying the internal quantum efficiency of eight different process technology variations. The sensors are characterized using light emitting diodes with a wavelength of 405 nm. At this wavelength, the light has an absorption depth of 125 nm, equivalent to that of 276 eV X-rays. The best variation achieves an internal quantum efficiency of 0.992 for 405 nm UV light. Based on this study, further optimization of the quantum efficiency for soft X-rays detection is planned.

The electronic system of the CMS Drift Tubes (DT) chambers will be replaced to continue operation during high luminosity running of the LHC (HL-LHC). The upgraded architecture sends all signals to the backend, where complex logic will be performed with a precision matching the maximum chamber resolution, now only available offline. A demonstrator has been installed during Long Shutdown 2 (LS2) in one of the sixty sectors of the detector. Over LS2 we have integrated this system in the CMS operations environment and tested its stability over extended cosmics data-taking campaigns, also with the magnetic field on. This paper describes the time synchronization achieved and early performance in collisions at Run 3 start.

The purpose of this study is to evaluate the effect of a lead radiation shield on the ability of a beam imaging device consist of an imaging plate (IP) and a collimator by Monte Carlo simulations. Simulations were performed using PHITS. A carbon-ion beam was injected to an acrylic target. A tungsten collimator having a pinhole was placed at the distance of 31.2 cm from the beam. A lead radiation shield was placed on the tungsten collimator. An IP was placed under the collimator. Beam images were acquired by recording the position distribution of energy deposition on the IP. We confirmed that therapeutic carbon-ion beam images could be acquired using the imaging device combining the IP and collimator. It was found that removal of the lead shield had no effect on the imaging results.

ALTIROC2 is a 225-channel ASIC designed in CMOS 130 nm to read out a 15 × 15 matrix of 1.3 mm × 1.3 mm Low Gain Avalanche Diodes (LGAD) for the ATLAS HGTD (High Granularity Timing Detector). The targeted combined time resolution of the sensor and its readout electronics range from 35 ps/hit (initial) to 65 ps/hit (end of operational lifetime). Each ASIC channel integrates a high-speed preamplifier followed by a high speed discriminator and two TDCs for Time-of-Arrival and Time-Over-Threshold measurements as well as a local memory. This front-end must exhibit a small jitter while keeping a challenging power consumption of less than 4.5 mW per channel. This conference proceeding summarizes the ASIC architecture, its measured performances compared to simulation, along with the requirements for the ATLAS HGTD experiments.

We report on our latest developments of a planar fiber-chip-coupling scheme, using angle polished, polarization maintaining (PM) fibers. Most integrated photonic chip components are polarization sensitive and a suitable way to launch several wavelength channels with the same polarization to the chip is the use of PM fibers. Those impose several challenges at processing and handling to achieve a stable, permanent, and low-loss coupling. We present the processing of the fibers in detail and experimental results for our planar and compact fiber-chip-coupling technique.

The CROCv1 front-end (FE) chip was designed by the RD53 collaboration for the CMS Phase-2 Inner Tracker Upgrade. It is designed to cope with the extreme radiation and hit rates of the HL-LHC and it is based on the 65 nm CMOS technology and a novel analog FE design featuring linear charge to Time-over-Threshold conversion. In this contribution, the characterization measurements of the analog part of the chip are presented with a special focus on the linear analog FE, including Total Ionizing Dose radiation damage studies.

The DUNE neutrino experiment far detector has a fiducial mass of 40 kt. The O(1M) readout channels are distributed over the four 10 kt modules and need to be synchronized with respect to each other to a precision of O(10 ns). The entire system needs to be synchronized with respect to GPS time to O(100 ns). The system needs to be reliable, simple and affordable. Clock and synchronization information are encoded on the same fibre using a protocol based on duty cycle shift keying (DCSK) with 8b10b encoding to ensure DC-balance. The use of DCSK allows the clock to be recovered directly by PLL based clock generators without needing to use a separate clock and data recovery (CDR) device. Small scale tests show a timing jitter at the endpoint of ≈10 ps with respect to the timing master.

The ARCADIA collaboration is developing fully-depleted (FD) Monolithic Active Pixel Sensors (MAPS) in a 110 nm CMOS process in collaboration with LFoundry. The sensor design incorporates an n+ collection node within a n-type epi-layer on top of a high-resistivity n-type substrate and p+ backside. Thus, the pn-junction sits on the backside and through an applied backside bias, the full substrate gets depleted. The targeted applications of this technology range from future high energy physics experiments to space applications, and medical and industrial scanners. Together, these applications set the minimum requirements on the detector: data collection at hit rates of (10–100) MHz/cm², full signal processing within (1–10) μs, maximum power consumption (5–20) mW/cm² and radiation tolerances of up to 3.4 Mrad or 6.2 × 10¹² 1 MeV neutron equivalent fluence. In order to proof the performance of the technology, a demonstrator chip of 512 × 512 pixels with 25 μm pitch was designed and fabricated in a first engineering run in 2021, together with additional test structures of pixel and strip arrays with different pitches and sensor geometries. The production run has produced functional passive and active pixel matrices. Earlier studies have shown that positive oxide charges and traps at the Si-SiO₂ interface, introduced by ionising radiation, affect the depletion region around the collection electrode, increasing the pixel capacitance. By varying the gap size between collection node and pwells, the geometry can be optimised to keep the capacitance low also after irradiation. To study the performance after irradiation, of the optimised diode designs, the passive pixel matrices were irradiated with doses up to 10 Mrad (SiO₂) using a X-ray tube with a Tungsten anode. The measurements are complemented by TCAD simulations. The maximum capacitance increase after irradiation was found to reach 6 and 12 fF/pixel for pixel pitches of 25 and 50 μm, respectively. The relative capacitance increase after irradiation has hereby been found to reach up to 250% after a dose of 10 Mrad.

A series of monolithic active pixel sensor prototypes (APTS chips) were manufactured in the TPSCo 65 nm CMOS imaging process in the framework of the CERN-EP R&D on monolithic sensors and the ALICE ITS3 upgrade project. Each APTS chip contains a 4 × 4 pixel matrix with fast analog outputs buffered to individual pads. To explore the process and sensor characteristics, various pixel pitches (10 µm–25 µm), geometries and reverse biasing schemes were included. Prototypes are fully functional with detailed sensor characterization ongoing. The design will be presented with some experimental results also correlating to some transistor measurements.

X-ray imagers with spectroscopic capabilities and high photon count rates are finding promising applications in industrial real-time inspection systems. In this context, XSpectra^® combines a CdTe-based linear energy-resolved photon counting (ERPC) pixel sensor with real-time image processing techniques to detect low and high density contaminants. The detection unit makes use of a new analog read-out ASIC that has been designed by Politecnico di Milano to meet strict application requirements both in energy resolution and achievable photon count rate. A room-temperature low-rate spectroscopic characterization of the system at a peaking time of 60 ns showed an average equivalent noise charge of 259 electrons r.m.s. (2.72 keV FWHM in CdTe) and an average FWHM of the 59.5 keV ²⁴¹Am line of 3.6 keV, with a 3σ dispersion in noise performance of ±10% over 256 channels. The detection unit was tested in high incoming photon flux conditions by means of an X-ray tube. Minimal spectral distortion due to pile-up events is obtained up to an Incoming Count Rate of 2.5 Mcps/channel, while the maximum counting capability of energy-resolved events is 2.2 Mcps/channel.

At airports and ports, X-ray security scanners based on dual-energy transmission imaging have been operated to prevent importation of contraband articles including weapons, narcotics, and explosives. Security scanners currently operated by the Korea Customs Service use a fixed tube voltage (i.e., 160 kVp); hence, it has a limitation in detecting thinly-coated and/or low-density organic contraband articles. Tube voltage lower than 160 kVp affords an advantage in terms of enhanced contrast for organic materials, albeit at the cost of penetration power, and vice versa. Therefore, a security scanner with variable tube voltage that is adjustable according to the physical/chemical properties of the object to be inspected, has the potential to improve detection probability for contraband articles. In the present study, security scanner design optimization specifically in terms of the X-ray generator and the dual-energy detector was performed by Monte Carlo (MC) simulations. Then, the performance of the designed system was evaluated using a simple phantom to demonstrate the advantages of the variable tube voltage application. Additionally, the standard kits were used for performance evaluation in terms of simple penetration and wire display, which are the two parameters specified in Korean law.

Coded Aperture γ-cameras have been used for more than three decades for imaging radioactive source distributions encountered in astrophysics, in decommissioning of nuclear facilities, and in nuclear medicine. These devices enable the identification of the coordinates of γ-emitters located within their Field of View (FOV) with the use of the coded-aperture shadow projected on pixelated detectors. In this work we have developed machine learning algorithms based on Gradient Boosted Decision Trees (BDTG) and Deep Neural Networks (DNN). The algorithms have been trained using 21000 shadowgrams created with simulation. A custom fast simulation tool was used to produce the shadowgrams due to sources placed randomly at different positions within the FOV at distances from 20 cm up to 20 m from the detector plane. The performance of the algorithms has been evaluated with the aid of a different independent simulation sample of shadowgrams and verified with real data.

The discovery of a large fab-to-fab variability in the TID response of the CMOS technologies used in the design of ASICs for the particle detectors of the HL-LHC triggered a monitoring effort to verify the consistency of the CMOS production process over time. As of 2014, 22 chips from 3 different fabs in 130 nm CMOS technology and 11 chips from 2 different fabs in 65 nm CMOS technology have been irradiated to ultra-high doses, ranging from 100 Mrad(SiO₂) to 1 Grad(SiO₂). This unprecedented monitoring effort revealed significant fab-to-fab and run-to-run variability, both dependent on the characteristics of the MOS transistors.

The emergence of high-precision timing systems in High Energy Physics motivates new developments in the domain of clock generation and distribution. Particularly, when considering the challenges arising from adopting advanced deep-submicron CMOS technology nodes, all-digital PLL and clock and data recovery (CDR) architectures constitute a promising option for future high energy physics (HEP) experiments. Both LC oscillator and ring oscillator-based all-digital PLL/CDR blocks for front-end ASICs were studied, designed, manufactured and characterized. Their design, the hardening considerations, as well as the performance obtained with these circuits are presented in this article.

X-ray phase contrast imaging (XPCI) techniques are sensitive to refraction (differential-phase) and small-angle X-ray scattering (dark-field) signals, not measurable with conventional absorption imaging techniques. Among XPCI techniques, edge illumination (EI), grating interferometry (GI), and speckle-based imaging (SBI) make use of wavefront markers, such as absorbing masks with periodical apertures or random diffusers, to encode refraction and dark-field signals induced by the sample. The Unified Modulated Pattern Analysis (UMPA) provides an algorithmic solution to extract the transmission, refraction, and dark-field images from EI, GI, and SBI datasets where the wavefront marker is directly resolved by the employed detection system. In its original implementation, UMPA has been designed for XPCI techniques sensitive to refractions along two axes. This work presents a modified version of the algorithm to extend its applicability to all the existing XPCI techniques that use wavefront markers with sensitivity to refraction limited along one direction (UMPA-1D). The algorithm, written in C++ and Cython and parallelized with OpenMP, enables fast reconstruction times that are particularly convenient for large tomographic datasets. The validity of the UMPA-1D has been demonstrated using both simulated images and real acquisitions with an EI setup in beam-tracking mode.

Continuing our research on X-ray R&D for aviation security, we designed a novel stationary computed tomography (SCT) baggage scanner with π-angle sparsity, comprising several dozen pairs of nanotube-based X-ray source and linear array-type detector placed within a scan angle of 180° at an equiangular distance. Simultaneously, we developed a reconstruction method for the specific configuration adopting an iterative algorithm based on the popular compressed-sensing (CS) scheme. To validate the efficacy of the proposed SCT design, we conducted a series of simulations using a numerical baggage phantom before its practical implementation. The results showed that the proposed SCT design and corresponding reconstruction method significantly reduced the streak artifacts appearing in the filtered-backprojection (FBP) reconstruction, thereby considerably improving the image quality. The contrast-to-noise ratio evaluated under a test condition of 180°/P20/CS was approximately 16.2, approximately 4.7 and 1.1 times larger than those for 360°/P20/FBP and 360°/P20/CS, respectively. The proposed SCT design enables saving scan time, improving image quality, and restricting radiation exposure zone.

A high-resolution clock phase shifter is implemented to adjust the phase of multiple clocks at 40 MHz, 80 MHz, or 640 MHz in the ALTIROC chip. The phase shifter has a coarse-phase shifter and a fine-phase shifter to achieve a step size of 97.7 ps and an adjustable range of 25 ns. The fine delay unit is based on a Delay Locked Loop (DLL) operating at 640 MHz. The phase shifter is fabricated in a 130 nm CMOS process. The area of the phase shifter is 725 µm × 248 µm. The Differential Non-Linearity (DNL) and the Integral Non-Linearity (INL) are ±0.6 LSB and ±0.75 LSB, respectively. The jitter from −25 °C to 20 °C is less than 15.5 ps (RMS), including the contributions from the FPGA clock source and the PLL. The power consumption is 11.2 mW.

Neutron detection is of great importance in many fields spanning from scientific research, to nuclear science, and to medical application. The development of silicon-based neutron detectors with enhanced neutron detection efficiency can offer several advantages such as spatial resolution, enhanced dynamic range and background discrimination. In this work, increased detection efficiency is pursued by fabricating high aspect ratio 3D micro-structures filled with neutron converting materials (B₄C) on planar silicon detectors. An in-depth feasibility study was carried out in all aspects of the sensor fabrication technology. Passivation of the etched structures was studied in detail, to ensure good electrical performance. The conformal deposition of B₄C with a newly developed process showed excellent results. Preliminary electrical characterisation of the completed devices is promising, and detectors have been mounted on dedicated boards in view of the upcoming tests with neutrons.

A new class of photon-counting pixel detectors allows for capturing of an image in several photon energy bins in one shot. A decreased pixel pitch and an increased number of energy bins are needed to enhance the spatial and spectral resolution of the detector. This led to new requirements for the readout systems and their bandwidths, as more data is generated for the same detection area. Fast differential serial communication enables high-speed data rates, thus providing an ideal solution to transfer large amounts of data generated by the detector's front-end electronics. However, its implementation provides extra challenges. This work introduces a novel high-speed serial readout designed in a 65 nm CMOS technology that will be used in the future photon-counting X-ray imaging detectors. The design of the serial transmitter is presented together with the characterization of jitter and channel performance.

Fast neutron detection is often based on the neutron-proton elastic scattering reaction: the ionization caused by recoil protons in a hydrogenous material constitutes the basic information for the design and development of a class of neutron detectors. Although experimental techniques have continuously improved, proton-recoil track imaging remains still at the frontier of n-detection systems, due to the high photon sensitivity required. Several state-of-the-art approaches for neutron tracking by using n-p single and double scattering — referred to as Recoil Proton Track Imaging (RPTI) — can be found in the literature. So far, they have showed limits in terms of detection efficiency, complexity, cost, and implementation. In order to address some of these deficiencies, we propose the design of RIPTIDE, a novel recoil-proton track imaging detector in which the light output produced by a fast scintillator is used to perform a complete reconstruction in space and time of the interaction events. The proposed idea is viable thanks to the dramatic advances in low noise and single photon counting achieved in the last decade by new scientific CMOS cameras as well as pixel sensors, like Timepix or MIMOSIS. In this contribution, we report the advances on the RIPTIDE concept: Geant4 Monte Carlo simulations, light collection tests as well as state-of-the-art approach to image readout, processing and fast analysis.

This work describes the architecture of a versatile system that is dedicated to the testing of various integrated circuits in radiation (e.g., ASICs, FPGAs). The system powers the device under test remotely. It monitors and reads out in real time various parameters, like: power consumption, voltage and current (with resolution of 100 µV and 100 µA, respectively), specific operational parameters of the device under test and its package temperature. A key feature of this system is its multi-channel and remote power supply capabilities, used to power the device under test. It embeds built-in features to detect and record single-event latch-ups, single event upsets and to monitor total ionizing dose cumulative effects. A graphical user interface allows the user to connect and to control the entire system through a dedicated ethernet interface from a safe location zone, and record to disk measurements data.

This paper presents the design and simulation of a prototype chip in the CMOS 40 nm process for high spatial resolution operation at the ESRF-EBS synchrotron. The core of the prototype IC is the pixel matrix with 50 µm pitch, operating in a single photon counting mode. Each pixel contains a Charge Sensitive Amplifier (CSA) with a fast discharge block and detector leakage current compensation circuit. The CSA output is directly connected to the discriminator with an offset trimming capability. The chip is optimized for operation with a monochromatic X-ray beam with an energy of up to 30 keV. Furthermore, several algorithms of interpixel communication are implemented in the chip to increase detector spatial resolution by using the charge sharing effect.

In this paper the results of a beam test characterization campaign of 3D trench silicon pixel sensors are presented. A time resolution in the order of 10 ps was measured both for non-irradiated and irradiated sensors up to a fluence of 2.5 × 10¹⁶ 1 MeV n_eq cm⁻². This feature and a detection efficiency close to 99% make this sensors one of the best candidates for 4D tracking detectors in High-Energy-Physics experiments.

Silicon photomultiplier (SiPM) are used to collect scintillation photons in many cryogenic noble liquid detectors deployed around the world, such as DarkSide, nEXO, MEGII, ProtoDUNE and DUNE. An event burst phenomenon was observed during routine characterization on many models of SiPMs operated in liquid nitrogen. These bursts of consecutive pulses are initiated by an intense dark photoelectron pulse with an event rate much lower than the time-uncorrelated thermal dark pulse. Although the rate of these burst events is very low, it can potentially compromise some dedicated rare physics event searches which are also anticipated to be of extremely low rate. Here, we systematically studied the behavior of the event burst phenomenon and identified the probable cause of the phenomenon. This investigation is important for the selection of SiPMs for use in noble liquid detectors, high energy physics experiments, and industrial applications where SiPMs are used in cryogenic environment.

This work presents the design and characterization results of a radiation hard bandgap reference circuit fabricated in a 110 nm CMOS technology for the Main Demonstrator chip of the ARCADIA project. The design, based on a current-mode approach in order to be able to output a smaller than 1.2 V reference voltage, employs diode-connected MOSFETs instead of BJTs to enhance the radiation hardness and a second amplifier to improve the current mirror of the output branch and therefore the line regulation of the circuit. This paper describes the features of the circuit and its measured results.

Fifty thousand hybrid circuits of five different types will be manufactured for the Phase-2 Upgrade of the CMS Outer Tracker. These circuits must undergo a strict quality control process, composed of functional testing and visual inspection, before they can be assembled into modules. The hybrids will be functionally tested first at the manufacturing site. Afterwards, they will be visually inspected and functionally tested again at CERN or at collaborating institutes. Results from these processes will be stored in the CMS production database. This paper presents the software tools developed to carry out these tasks.

The ALICE experiment at CERN is developing an innovative third iteration of the three innermost layers of the Inner Tracking System (ITS3) to be installed during the Long Shutdown 3 of the LHC (2026–28) [1]. Based on a commercial 65 nm CMOS imaging technology by TowerJazz [2], it consists of truly cylindrical wafer-scale sensors that can be installed as close as 18 mm to the interaction point. In order to validate the technology, several test chips were produced in a first submission named Multi-Layer Reticle 1 (MLR1). This contribution will describe the development, features, and performance of a custom test system for some of the prototypes in MLR1, namely Analogue and Digital Pixel Test Structures (APTS and DPTS, respectively) and pixel matrices with rolling shutter readout (CE65).

This contribution presents the results of the performance characterization and radiation tolerance evaluation of the SSA2 ASIC, the short-strip readout ASIC for the CMS Outer-Tracker PS-module. The ASIC performance is characterised by different temperatures and operating conditions, at the die level as well as at the wafer level. The radiation evaluation comprises Total-Ionising-Dose (TID) tests and Single-Event-Effects (SEEs). Wafer-level testing provided a large dataset to evaluate the production yield. The presented test results are in agreement with the design simulations and are well within the application requirements for operation in the CMS outer-tracker at the HL-LHC.

To cope with the increase of the luminosity at Run-3 of the LHC, new trigger readout electronics have been installed on the Liquid Argon Calorimeters. More than 1500 boards of the legacy system were refurbished and re-installed, 124 new on-detector boards and 116 new back-end mezzanine cards equipped with large FPGAs were added to digitize the calorimeter trigger signals. All the monitoring and control infrastructure is being adapted and commissioned. These proceedings will present the challenges of the installation, the commissioning, and the works still to be completed toward the full operation of both the legacy and the digital trigger in the LHC Run-3.

The MOnolithic Stitched Sensor (MOSS) is a development prototype chip towards the ITS3 vertexing detector for the ALICE experiment at the LHC. Designed using a 65 nm CMOS Imaging technology, it aims at profiting from the stitching technique to construct a single-die monolithic pixel detector of 1.4 cm × 26 cm. The MOSS prototype is one of the prototypes developed within the CERN-EP R&D framework to learn how to make stitched wafer-scale sensors with satisfactory yield. This contribution will describe some of the design challenges of a stitched pixel sensor and the techniques adopted during the development of this prototype.

The upgrade of the ATLAS ITk strips detector for HL-LHC will employ a custom PCB (powerboard) for on-module DC-DC conversion, HV switching, and monitoring. Production of about 14100 of such PCBs with high reliability is a big challenge. This paper will present the production procedure and quality control (QC) testing system for the powerboards to be installed on ITk Strip barrel modules. During production, about 150 powerboards will be produced every week. Each powerboard will need to pass QC tests before they are assembled to module. The QC tests include thermal cycling between −35 °C and 40 °C, soak test (continuous running of DC-DC converter at high load at 20 °C), and basic functionality and characterization electrical tests of the low voltage (LV), high voltage (HV), and monitoring functions of the powerboard. A custom QC test system is described, which is based on a reusable PCB (active board) with all testing circuits, a one-time powerboard carrier card, and a Z-turn SoC board which hosts and runs the testing program. The production procedure and QC test system has been tested with 400 powerboards during pre-production, and the system has been proven ready for production with the desired testing program, speed, safety, and cost. Performance and typical failures of powerboards observed during the QC test of pre-production powerboards is also presented.

The unique electrical and material properties of 4H-silicon-carbide (4H-SiC) make it a promising candidate material for high rate particle detectors. In contrast to the ubiquitously used silicon (Si), 4H-SiC offers a higher carrier saturation velocity and larger breakdown voltage, enabling a high intrinsic time resolution and mitigating pile-up effects. Additionally, as radiation hardness requirements grow more demanding in the context of future high luminosity high energy physics experiments, wide-bandgap materials such as 4H-SiC could offer better performance due to low dark currents and higher atomic displacement thresholds. In this work, the detector performance of 50 µm thick 4H-SiC p-in-n planar pad sensors was investigated at room temperature, using an ²⁴¹Am alpha source at reverse biases of up to 1100 V. Samples subjected to neutron irradiation with fluences of up to 1 × 10¹⁶ n_eq/cm² were included in the study in order to quantify the radiation hardness properties of 4H-SiC. A calibration of the absolute number of collected charges was performed using a GATE simulation. The obtained results are compared to previously performed UV transient current technique (TCT) studies. Samples exhibit a drop in charge collection efficiency (CCE) with increasing irradiation fluence, partially compensated at high reverse bias voltages far above full depletion voltage. At fluences of 5 × 10¹⁴ n_eq/cm² and 1 × 10¹⁵ n_eq/cm², CCEs of 64 % and 51 % are obtained, decreasing to 15 % at 5 × 10¹⁵ n_eq/cm². A plateau of the collected charges is observed in accordance with the depletion of the volume the alpha particles penetrate for an unirradiated reference detector. For the neutron-irradiated samples, such a plateau only becomes apparent at higher reverse bias, roughly 600 V and 900 V for neutron fluences of 5 × 10¹⁴ n_eq/cm² and 1 × 10¹⁵ n_eq/cm². For the highest investigated fluence, CCE behaves almost linearly with increasing reverse bias. Compared to UV-TCT measurements, the reverse bias required to deplete a sensitive volume covering full energy deposition is lower, due to the small penetration depth of the alpha particles. At the highest reverse bias, the measured CCE values agree well with earlier UV-TCT studies, with discrepancies between 1% and 5%.

A vertical slice of the CMS Outer Tracker has been tested at the tracker integration facility and at the M2 muon beam facility at CERN. It includes the final prototype of the 2S module with an optical link to the back-end ATCA system. The performance of the system will be described, including cooling limits of racks, robustness of 25 Gbit/s trigger optical links, and readiness of firmware.

Hybrid pixel detectors require a reliable and cost-effective interconnect technology adapted to the pitch and die sizes of the respective applications. During the ASIC and sensor R&D phase, and in general for small-scale applications, such interconnect technologies need to be suitable for the assembly of single-dies, typically available from Multi-Project-Wafer submissions. Within the CERN EP R&D programme and the AIDAinnova collaboration, innovative hybridisation concepts targeting vertex-detector applications at future colliders are under development. This contribution presents recent results of a newly developed in-house single-die interconnection process based on Anisotropic Conductive Film (ACF). The ACF interconnect technology replaces the solder bumps with conductive particles embedded in an adhesive film. The electro-mechanical connection between the sensor and the read-out chip is achieved via thermo-compression of the ACF using a flip-chip device bonder. A specific pad topology is required to enable the connection via conductive particles and create cavities into which excess epoxy can flow. This pixel-pad topology is achieved with an in-house Electroless Nickel Immersion Gold (ENIG) plating process that is also under development within the project. The ENIG and ACF processes are qualified with the Timepix3 ASIC and sensors, with 55 µm pixel pitch and 14 µm pad diameter. The ACF technology can also be used for ASIC-PCB/FPC integration, replacing wire bonding or large-pitch solder bumping techniques. This contribution introduces the ENIG plating and ACF processes and presents recent results on Timepix3 hybrid assemblies.

A Scalable Low Voltage Signaling (SLVS) transmitter and receiver have been developed as IP blocks in a 28 nm standard CMOS technology for the future upgrades for the high luminosity LHC. At the target data rate of 1.28 Gbps, the transmitter consumes 6 mW and the receiver consumes 2 mW. The transmitter's output is powered with 1.2 V to provide compatibility with previous designs, while the core logic can be powered with 0.8 V to reduce power consumption. This work summarizes the design approach at the schematic and layout level. Practical aspects of the novel technology for the design of ASICs in High Energy Physics will be discussed along with characterization results. Other IP blocks are being designed (ADC, DAC, PLL) and they will be presented.

Transient fault tolerance verification is a crucial step in the design of radiation-tolerant ASICs for high-energy physics experiments. In this paper, we discuss a methodical approach toward the verification of transient fault tolerance of ASICs using industry-standard methodologies and tools. The framework for fault verification includes tools for fault enumeration, fault injection, and running fault campaigns. The framework supports fault verification at various levels of design abstraction from high-level register-transfer model to gate-level netlist. The methodology and framework described in this paper were successfully used to identify SEE vulnerabilities in various ASICs designed at CERN.

The upgrade of the CMS detector for the high-luminosity LHC will include track-finding for the first time in the Level-1 trigger, enabling Particle Flow reconstruction of every event in addition to comprehensive pileup mitigation. The Correlator trigger will reconstruct isolated leptons and photons, hadronic jets, and energy sums, assisted in many cases by machine learning to benefit from the complete particle-level event record. We present the logic of these algorithms, possible implementations using large FPGAs and their demonstration in prototype hardware, in addition to the expected physics performance.

The ATLAS experiment is currently preparing for an upgrade of the inner tracking detector for the High-Luminosity LHC. The new tracker, ITk, employs an all-silicon detector with outer strip layers. The building block of the ITk strip barrel is the stave which consists of a low-mass support structure hosting the common electrical, optical and cooling services as well as 28 silicon modules. In this contribution, we outline the challenging aspects of the stave pre-production testing phase at Brookhaven National Laboratory. The electrical characterization of these staves, hosting the final design of all ASICs, will be discussed in detail.

The HKROC ASIC was originally designed to readout the photomultiplier tubes (PMTs) for the Hyper-Kamiokande (HK) experiment. HKROC is a very innovative ASIC capable of readout a large number of channels satisfying stringent requirements in terms of noise, speed and dynamic range. Each HKROC channel features a low-noise preamplifier and shapers, a 10-bit successive approximation Analog-to-Digital Converter (SAR-ADC) (designed by AGH Krakow) for the charge measurement (up to 2500 pC) and a Time-to-Digital Converter (TDC) (designed by CEA IRFU group) for the Time-of-Arrival (ToA) measurement with 25 ps binning. HKROC is auto-triggered and includes all necessary ancillary services as bandgap circuit, PLL (Phase-locked loop) and threshold DACs (Digital to Analog Converters). This paper will describe the ASIC architecture and the experimental results of the first HKROC prototype received in January 2022.

We present the architecture and current state of prototype firmware of the CMS Level-1 Global Trigger, the final stage of the new Level-1 trigger for Phase-2 of the LHC. Based on high-precision inputs from the muon, calorimeter, track and particle flow triggers, the Global Trigger evaluates O(1000) cut-based and neural-net-based algorithms in a system of up to thirteen Xilinx Ultrascale+ based ATCA processing boards interconnected by 25 Gb/s optical links. In order to optimize the usage of resources, the main algorithms, including the DSP-based calculation of invariant masses, are implemented at 480 MHz.

Semiconductor strip sensors applied as solid-state radiation or particle detectors can be used in radiation detection and measurement for various applications in particle physics experiments, X-ray imaging (e.g. medical), or material science. The X-ray imaging devices with spectroscopic and position resolution features are a very important research topic at many institutes and companies worldwide. Short strip silicon detectors are good candidates for X-ray spectroscopy, because of their relatively small capacitance and leakage current. If additionally, strip pitch is below 100 μm, then the high spatial resolution is also possible. In this paper, the analysis and noise optimization of the read-out electronics for short silicon strip detectors with Charge Sensitive Amplifier (CSA) and shaping amplifier (shaper) is presented. The CSA is optimized for the detector capacitance of around 1.5 pF, and the shaper nominal peaking time is about 1 μs (controlled by the sets of switches). We take into account the sources of noise in a radiation imaging system (current parallel noise, voltage series noise, and 1/f or flicker series noise) both internal (related to the front-end electronics itself) but also external, stemming from a sensor, interconnect, or printed circuit board parasitic components. We target the noise level below 40 el. rms, considering low power consumption (a few mW) and limited channel area.

Non-proliferation and the security of nuclear materials are essential. The international atomic energy agency (IAEA) considers a tomographic image acquisition technique of spent fuel assemblies a promising technique to accurately verify the rod-by-rod spent fuel conditions stored in a water pool. Researchers at Yonsei University in Korea developed the bismuth germanate (BGO) scintillator-based Yonsei Single-photon Emission Computed Tomography (YSECT). Previous research validated the YSECT system experimentally to quickly evaluate the radioactivity distribution of test fuel rods in the Korea Institute of Nuclear Nonproliferation and Control (KINAC). Quick verification of the fuel assembly requires the development of a high-quality image reconstruction algorithm that enables image acquisition within a short time. This study examined various tomographic image reconstruction techniques to identify patterns of missing fuel rods accurately. Rotational projection image data sets were obtained for 15 patterns of test fuel rods for 900 seconds using the single-photon emission computed tomography (SPECT) system installed at KINAC. The projection images were acquired every 5° while four 64-channel detectors rotated 90°. The acquired images were reconstructed using the following methods: filtered back-projection, simultaneous iterative reconstruction technique, order-subset simultaneous algebraic reconstruction technique, maximum likelihood expectation maximization (MLEM), and Fast-Iterative Shrinkage-Thresholding algorithm (FISTA). Among the reconstruction algorithms used in this study, the image quality of MLEM showed the best performance, and the image contrast of FISTA showed the highest result. Therefore, the signal-to-noise ratio of the tomographic image was improved using the image reconstruction technique optimized for the YSECT system to verify the patterns of fuel rods. Hence, even for the low-quality measured data with the short-time scan of the SPECT system, this advanced technique is expected to show better discriminability of the patterns of fuel rods in the assembly.

The LHC machine will be upgraded to increase its peak luminosity to 5–7.5 × 10³⁴ cm⁻² s⁻¹ and to possibly reach an integrated luminosity of 3000–4000 fb⁻¹, with an average number of pileup events of 140–200. The CMS experiment needs to be upgraded to keep up with the new challenges: the unprecedented radiation environment translates to the detector requirement of high resilience, while the increased number of events per bunch crossing requires higher detector granularity. Thus a completely new Inner Tracker will be installed. Design choices for the Inner Tracker Phase-2 upgrade, highlighting R&D activities and technological approaches, will be presented.

Hybrid single-photon counting pixel detectors have recently been widely used for X-ray and ionizing particle detection in medicine, high-energy physics, and material science. Many different chips have been developed for the readout of the semiconductor pixel sensor. Typically, developed ASICs have very limited digital logic and do not provide substantial data processing. In this paper, we present the readout chip that integrates the readout channels matrix with a RISC-V-based microprocessor SoC. The designed device has been prototyped in an FPGA and sent to production in a CMOS 40 nm process. Integration of a pixel matrix with the RISC-V-based central processing unit significantly improved the detector functionality. It enabled the device to work independently without external assistive device usage and execute many algorithms, e.g., calibration, threshold scanning, and data filtering, on-chip. Communication between the CPU and the pixel matrix was carried out through the dedicated Pixel Matrix Controller with the CPU standard I/O operations usage. This specialized peripheral consists of a coprocessor responsible for precise matrix control, a data converter for data conversion acceleration, and control and status registers connected to the core data bus. Many algorithms have been developed and tested, one of which is the intelligent real-time filtering of regions of interest.

The verification of ASICs through simulation is critical to ensure their successful operation in particle physics detectors and to minimize the number of long and expensive production cycles required. Three radiation-tolerant ASICs (HCC, AMAC, and ABC) will perform the front-end readout, monitoring, and control of the ITk Strip charged-particle tracker for the ATLAS detector at the HL-LHC. The Python-based cocotb verification framework is used to design sophisticated tests with contributions from ASIC verification non-experts and students. The verification program includes interactions between multiple ASICs, realistic data flows, operational stress tests, and a focus on mitigation of disruptive Single Event Effects due to radiation.

The High Luminosity Phase of the CERN Large Hadron Collider (HL-LHC) will require an extensive upgrade of the CMS Inner Tracking system based on high radiation tolerant silicon pixel sensors capable of withstanding fluences up to 23 × 10¹⁵ n_eq/cm² (1 MeV equivalent neutrons). Thin planar and 3D pixel sensors have been recently selected by CMS to be installed in the upgraded pixel tracker. Thanks to their structure, the 3D pixel sensors have some advantages with respect to planar ones, and are presently more suitable candidates for the innermost layer of the tracker. In this presentation results obtained with FBK planar and FBK 3D sensors readout by prototype read-out chip RD53A will be shown. Both sensor types have 25 × 100 μm² pitch and 150 μm thickness, and they were manufactured in collaboration with INFN. The sensors readout by the chip were irradiated to several fluences up to the one foreseen for HL-LHC. The analysis of collected data shows very high hit detection efficiency and good spatial resolution as measured after irradiation.

To cope with the challenges posed by the High-Luminosity LHC, the CMS experiment will feature a new silicon tracker. The modules of the upgraded inner tracker are hybrid silicon pixel modules based on a new readout chip, developed by the RD53 collaboration. Compared to the readout chip of the current pixel detector, the RD53 chip is capable of sustaining higher hit rates and radiation levels, as well as enabling the use of serial-powering chains. The qualification of the latest version of this chip (RD53B) is underway, and it will lead to the final version of the readout chip to be used in the CMS inner tracker during the HL-LHC. First digital modules featuring the RD53B-CMS chip have been assembled in 2022 (the term digital module denotes a module assembly with readout chips, but without sensors bonded to them). This contribution presents results of tests on these first prototype modules.

The high luminosity upgrade for the LHC at CERN requires a complete overhaul of the current inner detectors of ATLAS and CMS. A serial powering scheme has been chosen to cope with the constraints of the new pixel detectors. A prototype stave consisting of up to 8 quad modules, based on the new readout chips developed by the RD53 collaboration in 65 nm CMOS technology, RD53A and ITkPixV1, has been set up in Bonn. This contribution covers the results obtained with RD53A modules and presents first measurements with a full ITkPixV1.1 serial powering chain.

The FELIX system is used to interface the front-end electronics and the commodity hardware in the server farm of the ATLAS experiment. FELIX is using RDMA through RoCE to transmit data from its host servers to the Software Readout Driver using off-the-shelf networking equipment. In the current version of FELIX, RDMA communication is implemented using software on both ends of the links. Improvements of the data throughput as part of the High Luminosity LHC upgrade, by implementing RDMA support in the front-end FELIX FPGA, have been tested. A version of FELIX that uses the FPGA implementation of RDMA is being proposed and demonstrated.

The data link from the detectors to the back-end stage must keep up with the requirements from the upcoming generation of High Energy Physics experiments. Last year, we presented at TWEPP the investigation on the feasibility and limitation of high data-rate links based on the 4-Level Pulse-Amplitude Modulation (PAM4) technology. Commercial PAM4 technology poses strict constraints on the data rate of links which translates into a highly complex rad-hard SerDes design. Alternatively, pushing the limit of the Non-Return to Zero (NRZ) modulated signals, a line rate of up to 28 Gbps can be realized. This is less constraining thanks to the possibility of bypassing retimers of NRZ modules. As a part of the Work Package 6 of the CERN EP Research and Development programme, the feasibility as well as the availability in the telecom and datacom market of such NRZ links have been investigated. The rate of 25.65 Gbps per lane (an integer multiplication of the 40.0798 MHz Bunch Clock) with NRZ modulation have been identified as the target for the next generation of detector-to-backend links. The Demonstrator ASIC for Radiation-Tolerant Transmitter in 28 nm (DART28) chip, designed at 28 nm and targeting high-radiation hardness, is currently being designed at this data rate with a custom protocol and a Reed-Solomon Forward Error Correction (FEC). A proof-of-concept on FPGA emulating the DART28 protocol has been built for early evaluation. The system uses commercially available optoelectronics transceivers and FPGA platforms to implement the DART28 data path containing a scrambler, interleaver and FEC. The VCU129 Xilinx Virtex Ultrascale+ and Intel Stratix 10 evaluation boards were used for this work. In this paper, the implementation of the demonstrator systems will be presented. The performance characteristic of these links will be discussed and the FEC performance will be compared to that of an ideal model.

We describe a fast data-driven optical camera, Tpx3Cam, with nanosecond scale timing resolution and 80 Mpixel/sec throughput. After the addition of intensifier, the camera is single photon sensitive with quantum efficiency determined primarily by the intensifier photocathode. The single photon performance of the camera was characterized with results on the gain, timing resolution and afterpulsing reported here. The intensified camera was successfully used for measurements in a variety of applications including quantum applications. As an example of such application, which requires simultaneous detection of multiple photons, we describe registration of photon pairs from the spontaneous parametric down-conversion source in a spectrometer. We measured the photon wavelength and timing with respective precisions of 0.15 nm and 3 ns, and also demonstrated that the two photons are anti-correlated in energy.

Position and directional-sensitive spectrometry of energetic charged particles can be performed with high resolution and wide dynamic range (energy, direction) with the hybrid semiconductor pixel detectors Timepix/Timepix3. The choice of semiconductor sensor material, thickness, and properties such as the reverse bias voltage, greatly determine detector sensitivity and resolving power for spectrometry and particle tracking. We investigated and evaluated the spectral tracking resolving power such as deposited energy and linear-energy-transfer (LET) spectra with the Timepix3 detector with different semiconductor sensors, based on GaAs:Cr, CdTe, and Si, using well-defined radiation sources in terms of radiation type (protons), energy, and incident direction to the detector sensor. Measurements of particle incident direction in a wide range were performed with collimated monoenergetic proton beams of various energies in the range 8–31 MeV at the U120-M cyclotron at the NPI CAS Rez near Prague. All detectors were per-pixel calibrated. This work enables to examine and perform a detailed study of charge sharing and charge collection efficiency in semiconductor sensors. The results serve to optimise the detector chip-sensor assembly configuration for measurements especially with high-LET particles in ion radiotherapy and outer space. The work underway includes evaluation of newly refined semi-insulating GaAs sensors and improved radiation hard semiconductor sensors SiC.

For the High-Luminosity Large Hadron Collider, the trigger and data acquisition system of the CMS experiment will be entirely replaced. Novel design choices have been explored, including ATCA prototyping platforms with SoC controllers and newly available interconnect technologies with serial optical links with data rates up to 28 Gb/s. Trigger analyses will be performed through sophisticated algorithms, including widespread use of Machine Learning, in large FPGAs, such as the Xilinx Ultrascale family. The system will process over 50 Tb/s of detector data with an event rate of 750 kHz. We describe system design and prototyping and review trigger algorithm exemplars.

The ToASt ASIC is a 64 channel integrated circuit designed for the readout of the double-sided silicon strip sensors that will equip the micro-vertex detector of the PANDA experiment. The ToASt ASIC operates with a 160 MHz clock, which defines also the time resolution. A common time stamp is distributed to all channels to provide a common time reference for time of arrival and time over threshold measurements. Two 160 Mb/s serial lines provide the interface to the data concentrator. ToASt is implemented in a commercial 110 nm CMOS technology with triplicated logic to protect against single event upsets.

The Inner Tracker silicon strip detector (ITk Strip) is a part of the ATLAS upgrade for the HL-LHC. The detector readout and control is accomplished by the interaction of three on-module custom ASICs (ABCStarv1, HCCStarv1 and AMACstar). All ASICs are designed with protections against Single Event Errors. Their resilience at the system-level can be tested using the Board for Evaluation of Triple-chip Single Event Effects (BETSEE). This special board places all three ASICs into the beam-spot of a test beam facility concurrently and allows for module-like operation. The results from irradiating BETSEE with heavy ions and protons will be presented.

The increase in complexity and size of modern ASIC designs in the HEP community and the use of advanced semiconductor fabrication processes raises the need for a shift toward a more abstract design methodology, that takes advantage of modularity and programmability to achieve a faster turnaround time both for design and verification. This contribution will present two complementary approaches, one using a RISC-V based System-on-Chip (SoC) and the other based on Application-Specific Instruction set Processors (ASIP). The SoC uses the PicoRV32 open-source RISC-V core and a rad-hard version of the AMBA APB bus to connect peripherals and is primarily geared towards control and monitoring applications. This solution is a demonstrator of what can become a more complete fully radiation-tolerant SoC platform with a standardized interconnect and an IP block library, to serve as the starting point for future ASIC designs. The ASIP based approach targets more the design of data path elements and the use in data processing applications. The presented approach makes use of a commercial ASIP Designer EDA tool to demonstrate an integrated workflow to define, benchmark and optimize an ASIP for a specific use case, starting from a general-purpose processor.

Elemental mapping images can be achieved through step scanning imaging using pinhole optics or micro pore optics (MPO), or alternatively by full-field X-ray fluorescence imaging (FF-XRF). X-ray optics for FF-XRF can be manufactured with different micro-channel geometries such as square, hexagonal or circular channels. Each optic geometry creates different imaging artefacts. Square-channel MPOs generate a high intensity central spot due to two reflections via orthogonal channel walls inside a single channel, which is the desirable part for image formation, and two perpendicular lines forming a cross due to reflections in one plane only. Thus, we have studied the performance of a square-channel MPO in an FF-XRF imaging system. The setup consists of a commercially available MPO provided by Photonis and a Timepix3 readout chip with a silicon detector. Imaging of fluorescence from small metal particles has been used to obtain the point spread function (PSF) characteristics. The transmission through MPO channels and variation of the critical reflection angle are characterized by measurements of fluorescence from copper and titanium metal fragments. Since the critical angle of reflection is energy dependent, the cross-arm artefacts will affect the resolution differently for different fluorescence energies. It is possible to identify metal fragments due to the form of the PSF function. The PSF function can be further characterized using a Fourier transform to suppress diffuse background signals in the image.

This work proposes a methodology to quantify how the non-linearity of counting detectors due to pulse pile-up effects impacts detrimentally the signal-to-noise ratio of measurements and the resulting DQE. The method is presented from a conceptual point of view, justified and validated by both analytical and Monte Carlo methods applied to the ideal theoretical pile-up models usually discussed in the literature. Although the motivation of this work is the application to photon counting X-ray detectors, the study may be relevant for other type of particle or radiation detection systems operating at high count rate regimes, when pile-up is not negligible. The high count rates can be managed in actual experiments by implementing pile-up compensation methods in the detector readout chain, by applying correction algorithms to the measured data or by a combination of both. What has been less discussed in literature is the impact of those pile-up compensation techniques on the final statistical properties of the resulting data, and the proposed method can be potentially used for that purpose. The application of the method to more realistic systems is illustrated with an example of a simulated 2D X-ray photon counting detector that includes all the primary physical effects and the full readout chain.

The development of nuclear technologies, the production and active use of radioisotopes, and the production of radiopharmaceuticals, medical isotopes and other radioactive materials are increasing every year. Therefore, the importance of ensuring the safety of highly active isotopes, as well as providing the necessary instruments for measuring and identifying radioactive materials, must be taken into account. Modern equipment such as high purity germanium detectors (HPGe) is costly and requires specialized staff skills as well as special operating conditions such as low temperatures and high voltages. It is proposed to explore the possibilities of using a silicon photomultiplier (SiPM) with a deep pixel structure in nuclear gamma spectrometry, which will make it possible to increase the efficiency of scintillation detectors. The paper presents the results of a study of the newest silicon photomultipliers MAPD-3NM II assembled in a 16-element matrix, which was the detector part of the proposed LaBr₃(Ce) scintillation spectrometer. The study was carried out using radioisotopes of uranium. The aim of the research is to reveal the possibility of differentiating depleted and natural uranium materials from each other without using special software by means of the proposed set of equipment.

The LHCb Upgrade II aims at maximizing the potential for heavy flavour physics at high luminosity-LHC. The Vertex Locator (VELO) plays an important role in this task due to its excellent tracking and vertexing abilities. During Run 5 and 6, the detector will undergo through a substantial increase in data rate, pile-up and radiation damage. To achieve the same vertex reconstruction efficiency as the current Upgrade I detector, the introduction of timing and its possible implementations are discussed. Additional requirements for new sensor and ASIC technologies, introduced to cope with increased radiation damage, data rate and timing, are also presented. Finally, possible new detector layouts, adapted to expected conditions, are discussed and their impact on the RF-foil and vacuum tank geometries are treated.

For the CMS tracker Phase-2 upgrade new modules with silicon strip sensors are being developed.Each module features a Service Hybrid (SEH), which is responsible for the distribution of low voltages to the module components using a two-stage DC-DC conversion scheme.For modules equipped with the latest generation of SEHs an increase in module noise has been observed.A setup for inducing radiative noise with external magnetic fields that are frequency- and location-dependent is presented.Measurements carried out on modules from different prototyping phases show that the sensitivity is similar across generations, which indicates that radiative coupling into the sensor or readout electronics is not responsible for the observed noise increase.

In the pulp and paper industry, about 5 Mt/y chemithermomechanical pulp (CTMP) are produced globally from softwood chips for production of carton board grades. For tailor making CTMP for this purpose, wood chips are impregnated with aqueous sodium sulphite for sulphonation of the wood lignin. When lignin is sulphonated, the defibration of wood into pulp becomes more selective, resulting in enhanced pulp properties. On a microscopic fibre scale, however, one could strongly assume that the sulphonation of the wood structure is very uneven due to its macroscale size of wood chips. If this is the case and the sulphonation could be done significantly more evenly, the CTMP process could be more efficient and produce pulp even better suited for carton boards. Therefore, the present study aimed to develop a technique based on X-ray fluorescence microscopy imaging (µXRF) for quantifying the sulphur distribution on CTMP wood fibres. Firstly, the feasibility of µXRF imaging for sulphur homogeneity measurements in wood fibres needs investigation. Therefore, clarification of which spatial and spectral resolution that allows visualization of sulphur impregnation into single wood fibres is needed. Measurements of single fibre imaging were carried out at the Argonne National Laboratory's Advanced Photon Source (APS) synchrotron facility. With a synchrotron beam using one micrometre scanning step, images of elemental mapping are acquired from CTMP samples diluted with non-sulphonated pulp under specified conditions. Since the measurements show significant differences between sulphonated and non-sulphonated fibres, and a significant peak concentration in the shell of the sulphonated fibres, the proposed technique is found to be feasible. The required spatial resolution of the µXRF imaging for an on-site CTMP sulphur homogeneity measurement setup is about 15 µm, and the homogeneity measured along the fibre shells is suggested to be used as the CTMP sulphonation measurement parameter.

The time-to-digital-converter (TDC) using uncontrolled delay lines has a simple structure and finer measurement precision since the delay cells are pure digital gates that operate at maximum speed. For every incoming hit, two "snapshots" of the delay line are taken by the register array with two strobes separated with a known time interval. With two measurements, propagation delays of each cell in the delay line can be calibrated for the operating temperature and voltage. The two measurements can also be averaged to improve the TDC measurement precision. We will discuss various calibration approaches and present test results in this work.

ITk detector, the new ATLAS tracking system at High Luminosity LHC, will be equipped with 3D pixel sensor modules in the innermost layer (L0). The pixel cell dimensions will be either 25 × 100 μm² (barrel) or 50 × 50 μm² (endcap), with one read-out electrode at the centre of a pixel and four bias electrodes at the corners. Sensors from pre-production wafers (50 × 50 μm²) produced by FBK have been bump bonded to ITkPixV1.1 chips at IZM. Bare modules have been assembled in Genoa on Single Chip Cards and characterized in laboratory and on beam.

This paper presents the design and preliminary results of a shunt voltage regulator and two different bandgap reference designs for use with a monolithic High Voltage CMOS (HV-CMOS) sensor in a 150 nm technology node. One bandgap reference design is based on Bipolar Junction Transistors (BJTs) as the reference element of the circuit — the rest of the circuit is entirely designed with Metal–Oxide–Semiconductor Field-Effect Transistors (MOSFETs). The second bandgap reference design makes use of MOSFETs exclusively.

The next generation of high-energy physics experiments at future hadronic colliders will require tracking detectors able to efficiently operate in extreme radiation environments, where expected fluences will exceed 1 × 10¹⁷ n_eq/cm². This new operating scenario imposes many efforts on the design of effective and radiation-resistant particle detectors. Low-Gain Avalanche Diode (LGAD) represents a remarkable advance because the radiation damage effects can be mitigated by exploiting its charge multiplication mechanism after heavy irradiation. To obtain the desired gain (about 10–20) on the sensor output signal, a careful implementation of the "multiplication" region is needed (i.e.  the high-field junction implant). Moreover, a proper design of the peripheral region (namely, the guard-ring structure) is crucial to prevent premature breakdown and large leakage currents at very high fluences, when the bias voltage applied creates an electric field higher than 15 V/μm. In this contribution, the design of LGAD sensors for extreme fluence applications is discussed, addressing the critical technological aspects such as the choice of the active substrate thickness, the gain layer design and the optimization of the sensor periphery. The impact of several design strategies is evaluated with the aid of Technology-CAD (TCAD) simulations based on a recently proposed model for the numerical simulation of radiation damage effects on LGAD devices.

The radiation and magnetic field tolerant step-down DC/DC converter system is developed to supply low-voltage power for the ATLAS ITk Strip Detector. The system is modular and consists of custom designed crates with embedded cooling plates, backplane, and DC/DC converter modules. Each converter module comprises two or four power channels. Each channel comprises a 48-to-11 V DC/DC converter, hardware overcurrent and overvoltage protection circuits, correction circuitry to compensate for voltage drops along the cables, and control and monitoring functionality based on the AMACStar chip. We present the design and performance of such a DC/DC converter system, including evaluation of its radiation tolerance.

All the beamlines at modern synchrotron facilities are equipped with X-ray Beam Intensity or Position Monitors. Among those monitors, a relatively simple device is aiming at measuring the X-ray fluorescence and the X-ray scattering (elastic and inelastic) signal emitted from a thin foil with a punctual detector, a combination of several punctual detectors or a 2D detector. To improve the design of this kind of monitor, an analytical simulation has been developed to estimate the recording signal intensity according to the foil, the detector and the beam parameters. The mains X-ray interaction with matter processes involved in these monitors are simulated and several parameters of the incident X-ray beam are taken into account such as its intensity, energy, size and polarization. Furthermore, in contrast to the complex and time-consuming Monte-Carlo method, this analytical simulation is performed in few seconds and is implemented in a user-friendly interface. In order to validate our tool, the simulated results were compared to a series of measurements performed on the METROLOGIE beamline of the SOLEIL synchrotron. The differences with the experimental results are less than 30% by using a metallic foil and less than 50% with a Kapton® foil. The performances of our tool in term of accuracy, computation time and ease of use are perfectly adapted for the design of X-ray monitors based on an X-ray fluorescence and scattering foil.

The Large Hadron Collider (LHC) at CERN will be upgraded to the High-Luminosity LHC (HL-LHC) by 2029. In order to fully exploit the physics potential of the high luminosity era the experiments must undergo major upgrades. In the context of the upgrade of the Compact Muon Solenoid (CMS) experiment the silicon tracker will be fully replaced. The outer part of the new tracker (Outer Tracker) will be equipped with about 13,000 double-layer silicon sensor modules with two different flavors: PS modules consisting of a macro-pixel and a strip sensor and 2S modules using two strip sensors. These modules can discriminate between trajectories of charged particles with low and high transverse momentum. The different curvature of the trajectories in the CMS magnetic field leads to different hit signatures in the two sensor layers. By reading out both sensors, matching hits in the seed and correlation layer "stubs" are identified. This stub information is generated at the LHC bunch crossing frequency of 40 MHz and serves as input for the first stage of the CMS trigger. In order to quantify the hit and stub detection efficiency, beam tests have been performed. This article comprises selected studies from measurements gathered during two beam tests at the DESY test beam facility with 2S prototype modules assembled in 2021, featuring the Low Power Gigabit Transceiver (lpGBT). In order to compare the module performance at the beginning and end of the CMS runtime, a module with irradiated components has been built and intensively tested.

At national borders and high-security facilities, security screening is conducted to block the entrance of illicit goods such as weapons, explosives, and drugs. In the Republic of Korea, the Korea Customs Service currently conducts transmission X-ray security screening using fixed energy. However, the detection efficiency of this system for drugs or explosives composed of organic substances is rather low. Alternatively, the backscatter X-ray detection system is sensitive to materials of low atomic number; therefore, it can play an essential, complementary role in security screening. In the present study, the design of a pencil-beam-based backscatter X-ray security scanner was optimized and, subsequently, its performance was evaluated under various conditions using the Monte Carlo (MC) simulation technique. As for the X-ray generator, we optimized the tube voltage and the geometry of the chopper wheel collimator. Detector parameters including length, distance between detectors, and thickness also were optimized for detection efficiency. Finally, the performance of the optimized system was evaluated for various object conditions and postal phantoms.

The CMS experiment 40 MHz data scouting project is aimed at intercepting the data produced at the level of the detectors' front-end without the filters induced by hardware-based triggers. A first implementation is realized by the trigger-less reading and processing of a fraction of the Drift Tube (DT) muon detector, equipped with a preliminary version of the so-called Phase-2 Upgrade on-detector electronics boards. The data are transferred via high-speed optical links to back-end boards independently from the central experiment data acquisition (DAQ), permitting real-time detector status monitoring via receiving all the signals produced at the front-end level, and providing an unbiased estimate of the CMS DT hit-rate under various data-taking conditions.

The SpacePix2 monolithic active pixel sensor (MAPS) is a novel ASIC for space radiation monitoring designed in a 180 nm SOI CMOS technology. The active sensor area is 3.84 × 3.84 mm², pixel matrix is arranged as a 64 × 64 array with 60 µm pitch. The pixel front-end amplifier signal range is 2–80 ke⁻, extended up to 30 Me⁻ using a backside channel. Diodes integrated in the handle wafer in each pixel are biased at −150 V. Impinging particle generates a charge pulse converted to voltage pulse by charge sensitive amplifier (CSA). Maximum voltage memorized by the peak detector hold (PDH) circuit is digitized using on-chip 10-bit asynchronous column SAR ADCs. Two readout interfaces are available, 400 MHz LVDS and 50 MHz SPI. Total power consumption is 43 mA from a 1.8 V power supply. The ASIC has been tested in space in low Earth orbit (LEO) and sample data are shown.

Background and purpose: in-beam Positron Emission Tomography (PET) is one of the modalities that can be used for in-vivo non-invasive treatment monitoring in proton therapy. PET distributions obtained during various treatment sessions can be compared in order to identify regions that have anatomical changes. The purpose of this work is to test and compare different analysis methods in the context of inter-fractional PET image comparison for proton treatment verification.

Methods: for our study we used the FLUKA Monte Carlo code and artificially generated CT scans to simulate in-beam PET distributions at different stages during proton therapy treatment. We compared the Beam-Eye-View method, the Most-Likely-Shift method, the Voxel-Based-Morphology method and the gamma evaluation method to compare PET images at the start of treatment, and after a few weeks of treatment. The results were compared to the CT scan.

Results and conclusions: three-dimensional methods like VBM and gamma are preferred above two-dimensional methods like MLS and BEV if much statistics is available, since the these methods allow to identify the regions with anomalous activity. The VBM approach has as disadvantage that a larger number of MC simulations is needed. The gamma analysis has the disadvantage that no clinical indication exist on tolerance criteria. In terms of calculation time, the BEV and MLS method are preferred. We recommend to use the four methods together, in order to best identify the location and cause of the activity changes.

The particle identification of charged hadrons, especially for the separation of K and π, is crucial for the flavour physics study. Ionization measurement with the cluster counting technique, which has a much less fluctuation than traditionaldE/dx measurement, is expected to provide better particle identification for the BESIII experiment. Simulation studies, including a Garfield++ based waveform analysis and a performance study of K/π identification in the BESIII offline software system have been performed. The results show that K/π separation power and PID efficiency would be improved appreciably in the momentum range above 1.2 GeV/c using cluster counting technique even with a conservative resolution assumption.

In recent years, the Silicon Photomultipliers (SiPMs) have emerged as a promising photodetector in various applications such as high energy physics, nuclear physics and medical instruments. One such application is in the pixelated camera of Imaging Atmospheric Cherenkov Telescopes (IACTs). IACTs are used to detect very high-energy celestial gamma rays using Atmospheric Cherenkov Technique. The SiPM gain is proportional to the overvoltage which is the difference between applied bias voltage and breakdown voltage. As the SiPM breakdown voltage increases with temperature, the overvoltage and hence the gain decreases proportionally (2-3%/°C) at a constant applied bias voltage. Also, the actual bias voltage across the SiPM changes with load current due to voltage drop across a series resistor in SiPM bias circuit, thus causing a change in overvoltage and gain. To maintain a constant gain of the SiPM, the applied bias voltage need to be adjusted to compensate for the changes in temperature and load. We are developing a 256-pixel imaging camera with SiPM as its photo-sensor. The camera will be placed at the focal point of telescope and will be operated during night in outdoor environment at Hanle, Ladakh, India. The night temperature at Hanle typically varies by ∼ 10°C overnight and ∼ 40°C (-20°C to +20°C) over the year. Thus, gain of SiPMs, exposed to the environment, may vary considerably during observations. A prototype 8-channel bias supply board with real time temperature & load compensation is developed to operate the camera SiPMs at fixed gain throughout the observation night.

The voltage range of the bias supply for each channel is from 10 V to 80 V with 5 mV resolution and current upto 4 mA. The output voltage and current can be monitored with a resolution of ∼ 5 mV and ∼ 0.3 μA respectively. The single board computer, Raspberry Pi, is connected to the bias supply board over a 7-wire Customized Serial Peripheral Interface (CSPI) for control and monitoring. A multi-channel SiPM bias supply system is realized by daisy-chaining 8-channel boards through CSPI to cater bias voltage to all the pixels of the camera. The system is operated remotely using Ethernet interface of Raspberry-Pi. This paper discusses the design, development and performance of the prototype 16-channel closed-loop, programmable bias supply system with built-in compensation for changes in temperature and load.

The protection of superconducting magnets is a very important issue and demanding challenge in the LHC and other superconducting accelerating facilities. The quench phenomenon can destroy components of the accelerator, and therefore this digital system was designed, implemented, tested, and installed near each superconducting magnet in the LHC tunnel. The quench detection principle relies on the extraction of resistive voltage by compensation of the inductive part of the voltage. This article presents briefly the architecture applied to the design and the validation of the FPGA-based quench detector for the main quadrupoles of the LHC. The article focusses on digital design with the use of FPGA by VHDL coding and on the verification by simulation. The design is a replacement for the old detection system.

We describe a low-cost system designed to monitor wander in digital clocks with a precision of ≤ 1 ps. With this system we have shown that it is possible to track phase variations at the sub-picosecond level by adding noise to a reference clock. As in many cases where a clock is part of a complex distribution network small changes in temperature and other effects can lead to small changes in the clock's phase. As a further demonstration of the system, we have used it to measure the phase changes induced in optical signals in fibers.

The KAHVE Laboratory, at Boğaziçi University, Istanbul, Turkey is home to an educational proton linac project. The proton beam will originate from a 20 keV H+ source and will be delivered to a two module Radio Frequency Quadrupole (RFQ) operating at 800 MHz via a low energy beam transport (LEBT) line. Currently, the design phase being over, commissioning and stability tests are ongoing for the proton beamline which is already produced and installed except the RFQ which is being manufactured. This work summarizes the design, production and test phases of the ion source and LEBT line components.

The Experimental Advanced Superconducting Tokamak (EAST) reflectometry is a Frequency-Modulated Continuous-Wave monostatic system with the transmission lines similar to the ITER reflectometer design. One of the most significant and common problems for reflectometry to reconstruct the density profile is the determination of initialization, i.e. zero density position (R_start), which could be determined by the extraordinary mode (X-mode) reflectometry. The main source of noise still comes from the wave scattering of plasmas despite the sweeping period of around 10 microseconds. It is found that to reduce the random noise of R_start, averaging on 25 periods is the optimal solution. During the L-mode discharges with only lower hybrid wave (LHW) heating, R_start would move outwards and its fluctuation and the high frequency components of turbulence around R_start would be obviously increased when the 2.45 GHz system is switched on, while no obvious change is observed in the 4.6 GHz case. These phenomena are consistent with that 2.45 GHz LHW has less current drive ability than 4.6 GHz LHW on EAST. During ELMy H-mode, the peak of R_start is consistent with Deuterium signal and the maximum displacement is about 3 cm. The comparison of density profiles from reflectometry and Lithium beam emission spectroscopy (Li-BES) suggests that setting the density at R_start to (4 ± 2)× 10¹⁷ m^-3 is much better than zero, while this value is somewhat empirical and closely related to the amplitude threshold for determining the first probing frequency corresponding to R_start.