Table of contents

Longitudinal prompt-gamma ray profiles have been measured with a multi-slit multi-detector configuration at a 75 MeV/u ¹³C beam and with a PMMA target. Selections in time-of-flight and energy have been applied in order to discriminate prompt-gamma rays produced in the target from background events. The ion ranges which have been extracted from each individual detector module agree amongst each other and are consistent with theoretical expectations. In a separate dedicated experiment with 200 MeV/u ¹²C ions the fraction of inter-detector scattering has been determined to be on the 10%-level via a combination of experimental results and simulations. At the same experiment different collimator configurations have been tested and the shielding properties of tungsten and lead for prompt-gamma rays have been measured.

In this paper we present the experimental results for the mobility of ions in argon-carbon dioxide gaseous mixtures (Ar-CO₂) for pressures ranging from 6 to 10 Torr and for reduced electric fields in the 10 Td to 25 Td range, at room temperature.The time-of-arrival spectra of the several mixture ratios studied revealed that the relative abundance of the ions and their mobilities depend on the mixture ratio. For Ar concentrations below 80% only one peak was observed in the spectra which was attributed to CO₂⁺, while for Ar concentrations above 80% a second peak appears at the left side of the main peak, which may be due to impurities, probably H₂O⁺. In this work, the time-of-arrival spectra from which reduced mobilities were obtained for Ar concentrations of 20% (K₀ = 1.141±0.004 cm²V⁻¹s⁻¹), 50% (K₀ = 1.385±0.009 cm²V⁻¹s⁻¹), 85% (K₀ = 1.690±0.022 cm²V⁻¹s⁻¹) and 95% (K₀ = 1.954±0.043 cm²V⁻¹s⁻¹) are displayed as well as other reduced mobilities values obtained similarly. The ion mobility study was performed at reduced electric field values typically used in gaseous detectors.

A resonant circuit tuned to a particular frequency of the motion of charged particles stored in a Penning trap and connected to a low noise amplifier allows, at the same time, cooling and non destructive detection of the particles. Its use is widely diffused when single or few particles are stored near the centre of a hyperbolic Penning trap. We present a consistent model that predicts the shape of the induced signal when the tuned circuit is used to detect and cool the axial motion of a cold non neutral plasma stored in an open-ended cylindrical Penning trap. The model correctly accounts for the not negligible axial plasma size. We show that the power spectrum of the signal measured across the tuned circuit provides information about the particle number and insights about the plasma temperature. We report on the design of a HEMT-based cryogenic amplifier working at 14.4 MHz and 4.2 K and the results of the noise measurements. We have measured a drain current noise in the range from 6 to 17 pA/√Hz, which corresponds to an increase of the tuned circuit equivalent temperature of at maximum 0.35 K. The cryogenic amplifier has a very low power consumption from few tens to few hundreds of μW corresponding to a drain current in the range 100–800 μ A. An additional contribution due to the gate noise has been identified when the drain current is below 300 μA; above that value an upper limit of the increase of the equivalent tuned circuit temperature due to this contribution of 0.02 K has been obtained. These features make the tuned circuit connected to this amplifier a promising device for detecting and cooling the axial motion of an electron plasma when the Penning trap is mounted inside a dilution refrigerator.

In this paper we present the first direct microdosimetric measurements of 62 MeV proton beams using ultra-thin 3D silicon detectors at different depths in a solid-water phantom. The detectors have 3D columnar electrodes that penetrate a 10 μm thick silicon membrane, resulting in a micrometric scale sensitive volume. The 62 MeV proton beam was generated in a cyclotron CYCLONE-110 at Centre de Recherches du Cyclotron (CRC) at Louvain-la-Neuve. The proton beam average energy was modulated with stacked tissue-equivalent solid water layers. The energy loss profile was studied through the Bragg curve and pulse height spectra. The experimental silicon microdosimetric spectra showed the lineal energy dependence along the Bragg curve. This work demonstrates the potential capability of the ultra-thin 3D silicon detectors as 3D detector technology-based microdosimeters.

Proton therapy is a high precision technique in cancer radiation therapy which allows irradiating the tumor with minimal damage to the surrounding healthy tissues. Pencil beam scanning is the most advanced dose distribution technique and it is based on a variable energy beam of a few millimeters FWHM which is moved to cover the target volume. Due to spurious effects of the accelerator, of dose distribution system and to the unavoidable scattering inside the patient's body, the pencil beam is surrounded by a halo that produces a peripheral dose. To assess this issue, nuclear emulsion films interleaved with tissue equivalent material were used for the first time to characterize the beam in the halo region and to experimentally evaluate the corresponding dose. The high-precision tracking performance of the emulsion films allowed studying the angular distribution of the protons in the halo. Measurements with this technique were performed on the clinical beam of the Gantry1 at the Paul Scherrer Institute. Proton tracks were identified in the emulsion films and the track density was studied at several depths. The corresponding dose was assessed by Monte Carlo simulations and the dose profile was obtained as a function of the distance from the center of the beam spot.

This article describes the design features and the first test measurements obtained during the installation of a novel high resolution 2D neutron detection technique. The technique proposed in this work consists of a boron layer (enriched in ¹⁰B) placed on a scientific Charge Coupled Device (CCD). After the nuclear reaction ¹⁰B(n,α)⁷Li, the CCD detects the emitted charge particles thus obtaining information on the neutron absorption position. The above-mentioned ionizing particles, with energies in the range 0.5–5.5 MeV, produce a plasma effect in the CCD which is recorded as a circular spot. This characteristic circular shape, as well as the relationship observed between the spot diameter and the charge collected, is used for the event recognition, allowing the discrimination of undesirable gamma events. We present the first results recently obtained with this technique, which has the potential to perform neutron tomography investigations with a spatial resolution better than that previously achieved. Numerical simulations indicate that the spatial resolution of this technique will be about 15 μm, and the intrinsic detection efficiency for thermal neutrons will be about 3%. We compare the proposed technique with other neutron detection techniques and analyze its advantages and disadvantages.

In positron emission tomography, the constant fraction discriminator (CFD) circuit is used to acquire accurate arrival times for the annihilation photons with minimum sensitivity to time walk. As the number of readout channels increases, it becomes difficult to use conventional CFDs because of the large amount of space required for the delay line part of the circuit. To make the CFD compact, flexible, and easily controllable, a non-delay-line CFD based on the Padé approximant is proposed. The non-delay-line CFD developed in this study is shown to have timing performance that is similar to that of a conventional delay-line-based CFD in terms of the coincidence resolving time of a fast photomultiplier tube detector. This CFD can easily be applied to various positron emission tomography system designs that contain high-density detectors with multi-channel structures.

Image correction for scattered photons is important for the quantification of gamma-camera imaging using I-131. Many previous studies have addressed this issue but none have compared scattered photon fractions of I-131 with varying energy windows, to determine optimal main- and sub-energy windows for the implementation of TEW correction in I-131 imaging. We assessed the scattered photon fractions and determined the optimal main- and sub- energy windows for TEW in I-131 using a Siemens SYMBIA T2 SPECT/CT using a Monte Carlo method (GATE simulation). To validate the GATE simulation code, we compared the spatial resolutions obtained experimentally and from GATE simulation, for I-123 and Tc-99m. A high-energy general purpose (HE) collimator was used to assess the scattered photon fractions measured with the I-131 radioisotope placed at eight different field-of-view locations in a water phantom (diameter 16 cm, length 32 cm), and at the center in air. To implement the TEW (triple energy window) method, two different main-energy window widths (15 and 20%) and two different sub-energy window widths (3 and 5 keV) were used. The experimental measurement and simulation results exhibited a similar pattern with < 15% difference in spatial resolution with increasing distance. The I-131 scatter fraction with 15% of the main-energy window and 5 keV sub-energy windows was similar to the ``goldstandard'' scatter fraction. Main- and sub-energy window selection for the TEW correction in I-131 is important to avoid over- or under-correction in the scatter fraction. A 15% of main energy window with 5 keV sub-energy windows were found to be optimal for implementation of the TEW method in I-131. This result provides the optimal energy window for I-131 scintigraphy data and will aid the quantification of I-131 imaging.

Photon counting detection with energy resolution and the consequent possibility to improve image quality become possible with the development of energy resolved detectors.

The 2D-Thick-COBRA (2D-THCOBRA), a recently introduced MicroPattern Gaseous Detector (MPGD), with an active area of 10 × 10 cm², specially designed for imaging purposes allows to determine the interaction position and also the energy of each single photon reaching the detector.

In this work, the performance of a single 2D-THCOBRA operating in Ne/CH₄ (95/5) (at 1 bar) is presented based on studies of charge gain, energy resolution, count rate, stability and spatial resolution. The detector shown a very stable operation allowing for gains of about 10⁴. An energy resolution of 22% for 8 keV, count rates up to 1 × 10⁶ Hz/mm² and a spatial resolution of about 1.2 mm were achieved with this detector.

Some examples of X-ray transmission imaging of some biological samples are also shown.

A system constituted by a Silicon Drift Detector (SDD), fabricated with an innovative technology for minimizing the anode current, and a new CMOS charge sensitive preamplifier (CSA), designed for ultimate low noise performance, has been realized and experimentally characterized. The SDD is hexagonal with an active area of 13 mm². The current density measured at the anode with the detector in operating condition is 25 pA/cm² at +20°C. The CSA—named SIRIO—has intrinsic Equivalent Noise Charge (ENC) ranging from 2.9 to 1.5 electrons r.m.s. at 0.8 μs and 11 μs peaking times at room temperature, respectively. With the SDD-SIRIO system at +21°C, an energy resolution of 141 eV FWHM on the ⁵⁵Fe line at 5.9 keV and 74 eV FWHM on the pulser line with a noise threshold of 170 eV have been measured at 0.8 μs peaking time. The system has been tested from −30°C to +30°C with energy resolution from 124 eV to 148 eV FWHM at 5.9 keV. A moderate cooling at +10°C is sufficient to reach 133 eV FWHM at 5.9 keV.

A new approach to absolute determination of the neutron source yield is presented. It bases on the application of melamine (C₃H₆N₆) to neutron detection combined with Monte Carlo simulations of neutron transport. Melamine has the ability to detect neutrons via ¹⁴N(n, p)¹⁴C reaction and subsequent determination of ¹⁴C content. A cross section for this reaction is relatively high for thermal neutrons (1.827 b) and much lower for fast neutrons. A concentration of ¹⁴C nuclei created in the irradiated sample of melamine can be reliably measured with the aid of the accelerator mass spectrometry (AMS). The mass of melamine sufficient for this analysis is only 10 mg. Neutron detection is supported by Monte Carlo simulations of neutron transport carried out with the use of MCNP-4C code. These simulations are aimed at computing the probability of ¹⁴C creation in the melamine sample per the source neutron. The result of AMS measurements together with results of MCNP calculations enable us to determine the number of neutrons emitted from the source during the irradiation of melamine.

The proposed method was applied for determining the neutron emission from a commercial ²⁵²Cf neutron source which was independently calibrated. The measured neutron emission agreed with the certified one within uncertainty limits. The relative expanded uncertainty (k=2) of the absolute neutron source yield determination was estimated at 2.6%.

Apart from calibration of radionuclide neutron sources the proposed procedure could facilitate absolute yield measurements for more complex sources. Potential applications of this methodology as it is further developed include diagnostics of inertial confinement fusion and plasma-focus experiments, calibration of neutron measurement systems at tokamaks and accelerator-based neutron sources as well as characterization of neutron fields generated in large particle detectors during collisions of hadron beams.

The LHCb Vertex Detector (VELO) will be upgraded in 2018 along with the other subsystems of LHCb in order to enable full readout at 40 MHz, with the data fed directly to the software triggering algorithms. The upgraded VELO is a lightweight hybrid pixel detector operating in vacuum in close proximity to the LHC beams.

The readout will be provided by a dedicated front-end ASIC, dubbed VeloPix, matched to the LHCb readout requirements and the 55 × 55 μm VELO pixel dimensions. The chip is closely related to the Timepix3, from the Medipix family of ASICs. The principal challenge that the chip has to meet is a hit rate of up to 900 Mhits/s, resulting in a required output bandwidth of more than 16 Gbit/s. The occupancy across the chip is also very non-uniform, and the radiation levels reach an integrated 400 Mrad over the lifetime of the detector.VeloPix is a binary pixel readout chip with a data driven readout, designed in 130 nm CMOS technology. The pixels are combined into groups of 2 × 4 super pixels, enabling a shared logic and a reduction of bandwidth due to combined address and time stamp information. The pixel hits are combined with other simultaneous hits in the same super pixel, time stamped, and immediately driven off-chip. The analog front-end must be sufficiently fast to accurately time stamp the data, with a small enough dead time to minimize data loss in the most occupied regions of the chip. The data is driven off chip with a custom designed high speed serialiser. The current status of the ASIC design, the chip architecture and the simulations will be described.

The Beam Instrumentation Group at CERN is designing a new general-purpose VME carrier module utilising several PTH04T230W DC/DC converters. These off-the-shelf converters are built with unshielded inductors and need to be mounted on the printed circuit board as stand-alone components. Thus, reducing the global manageability and increasing the total cost of the carrier module. The new design aims to develop a module with better power dissipation, efficiency and reliability. In the future, it should be also possible to be directly integrated on the mainboard. For this reason, a Buck DC/DC converter has been implemented with the following main characteristics: input range from 3.0 V to 5.5 V; output range from 0.6 V to 3.3 V, settable by means of an external resistor; output current protection at 6 A; maximum output ripple ± 50 mVpp; switching frequency of 300KHz; short circuit protection; On/Off function; EMI reduction with frequency spread spectrum; soft-start function and thermal shutdown, in a 16 × 19 mm compact size. The selected buck controller is the TPS40303 integrated circuit and drives the CSD16321 power MOSFET, both from Texas Instruments. All selected components have been used at a minimum derating of 50% to reduce component stress and increase the reliability of this module. The selected inductors, i.e. Bourns SRP1055, are the main contributor for the high efficiency (95%), due to their very low equivalent series resistance. On the 4-layer PCB comprising all the components of this module, a snubber circuit, for further reduction of the output ripple due to the MOSFET ringing, can be mounted optionally. It is left as an option due to its effect on the total efficiency. The board layout has been optimized for maximum heat transfer and it can be used without active cooling. The board can maintain the maximum temperature on its surface, while at maximum current output, below 55°C at 25°C ambient temperature. An example of the electrical performance simulation, as well as the verification methodology and the test bench realised will be shown.

This work presents the design of a low-power, differential signaling, input/output data link in a 65 nm CMOS process for high energy physics (HEP) experiments. The proposed driver, able to operate at 320 Mbps or 640 Mbps with a normalized power dissipation of 3.125 mW/Gbps, is meant to drive short distance (between 2 and 10 cm) transmission lines located to the module hybrid circuit. A de-emphasis technique has been adopted to reduce the impedance mismatch effects between the driver output and the transmission line. This paper will discuss in detail the solutions implemented in the design and will describe the simulation results.

A new front-end chip (VeloPix) is being developed for the readout of the silicon vertex locator detector (VELO) in the LHCb experiment after the upgrade scheduled for 2018.

The chip with an active area of 2 cm² will run at a very high hit rate (up to 500 Mhitcm⁻²sec⁻¹) and will transmit large amounts of data (> 15 Gbit-per-sec) over a 1 meter low-mass copper cable. A test chip with a prototype of a 5.12 Gbps Data Serializer and Wireline Transmitter (line driver) circuit has been submitted in 130 nm CMOS technology. A multiplexer based architecture has been chosen for the implementation the serializer block. In the proposed solution a 16-to-1 round-robin multiplexer selects one bit of data at a time from either a posedge triggered section or a negedge triggered section of a 16-bit input register clocked at 320 MHz. The serializer consumes only 15 mW of power and the line driver with pre-emphasis consumes 45 mW. In this paper the circuit design is explained and some measured results are presented.

We have developed an electron-tracking Compton camera (ETCC) for use in next-generation MeV gamma ray telescopes. An ETCC consists of a gaseous time projection chamber (TPC) and pixel scintillator arrays (PSAs). Since the TPC measures the three dimensional tracks of Compton-recoil electrons, the ETCC can completely reconstruct the incident gamma rays. Moreover, the ETCC demonstrates efficient background rejection power in Compton-kinematics tests, identifies particle from the energy deposit rate (dE/dX) registered in the TPC, and provides high quality imaging by completely reconstructing the Compton scattering process. We are planning the ``Sub-MeV gamma ray Imaging Loaded-on-balloon Experiment'' (SMILE) for our proposed all-sky survey satellite. Performance tests of a mid-sized (30 cm)³ ETCC, constructed for observing the Crab nebula, are ongoing. However, observations at balloon altitudes or satellite orbits are obstructed by radiation background from the atmosphere and the detector itself [1]. The background rejection power was checked using proton accelerator experiments conducted at the Research Center for Nuclear Physics, Osaka University. To create the intense radiation fields encountered in space, which comprise gamma rays, neutrons, protons, and other energetic entities, we irradiated a water target with a 140 MeV proton beam and placed a SMILE-II ETCC near the target. In this situation, the counting rate was five times than that expected at the balloon altitude. Nonetheless, the ETCC stably operated and identified particles sufficiently to obtain a clear gamma ray image of the checking source. Here, we report the performance of our detector and demonstrate its effective background rejection based in electron tracking experiments.

The pixel detector of the CMS experiment will be exchanged during the year-end technical stop in 2016/2017, as part of the experiment's Phase-1 upgrade. The new device will feature approximately twice the number of readout channels, and consequently the power consumption will be doubled. By moving to a DC-DC conversion powering scheme, it is possible to power the new pixel detector with the existing power supplies and cable plant.

The power system of the Phase-1 pixel detector is described and the performance of the new components, including DC-DC converters, DC-DC converter motherboards and various power distribution boards, is detailed. The outcome of system tests in terms of electrical behaviour, thermal management and pixel module performance is discussed.

Clock distribution circuits account for a significant fraction of the power dissipation of the Macro Pixel ASIC (MPA), designed for the pixel layer readout of the so-called Pixel-Strip module in the innermost part of the CMS tracker at the HL-LHC. This work reviews different CMOS circuit architectures envisioned for low power clock distribution in the MPA. Two main topologies will be discussed, based on standard supply voltage and on auxiliary, reduced supply. Circuit performance, in terms of power consumption and speed, is evaluated for each of the proposed solutions and compared with that relevant to standard CMOS drivers.

In this paper, a remote FPGA-configuration method based on JTAG extension over optical fibers is presented. The method takes advantage of commercial components and ready-to-use software such as iMPACT and does not require any hardware or software development. The method combines the advantages of the slow remote JTAG configuration and the fast local flash memory configuration. The method has been verified successfully and used in the Demonstrator of Liquid-Argon Trigger Digitization Board (LTDB) for the ATLAS liquid argon calorimeter Phase-I trigger upgrade. All components on the FPGA side are verified to meet the radiation tolerance requirements.

The Belle II detector is a system currently under upgrade at the B-factory SuperKEKB in Tsukuba, Japan. The main novelty is the introduction of an additional position sensitive sub-detector in the vertex detector, between the beam pipe and the strip detector system. The sensor of choice for the Belle II Pixel Detector is the Depleted p-channel Field Effect Transistor (DEPFET) sensor. In this paper the latest production of sensors and prototypes performed at the semiconductor Laboratory of the Max Planck Society, i.e. the PXD9 and the Electrical Multi-Chip Module (EMCM), are described. Wafer-level characterisation methods and techniques for faults in the metal system are also reported.

Detectors based on silicon have been proven to be efficient for particle tracking in high energy physics collider experiments. The Compact Muon Solenoid (CMS) Tracker at CERN near Geneva has a silicon detector surface of about 200 m². The increasing demand on more collected data for new physics studies requires an upgrade of the Large Hadron Collider to higher luminosity which is foreseen for 2023. The increase of particles per time and area also introduces a harsh environment for the silicon sensors which should withstand an integrated luminosity of about L=3000 fb⁻¹. Several R&D studies have been undertaken to face the high luminosity challenge and n-in-p detectors have been found to be more radiation hard than p-in-n.

However, n-in-p detectors necessarily need an isolation layer of the n+ strips due to an accumulation layer of electrons caused by positive charge in the SiO₂ at the sensor surface. An additional implantation of acceptors like boron between the n+ strips cuts the conducting electron layer and ensures reliable strip isolation. However, the implantation dose as well as the implant energy have to be carefully calculated as they directly affect the breakdown behavior and inter-strip resistance of the sensors. Experimentally, the inter-strip resistance (R_int) and charge collection efficiency (CCE) as well as the cluster charge formation are a direct indicator whether the isolation layer is sufficient or not. Furthermore T-CAD simulation studies have been carried out in order to reproduce the measurements and to predict the performance of sensors before and after irradiation with protons, neutrons and a mixture of both. Simulations also allow detailed studies of the formation of electric fields in the sensor which influence the sensor performance. Experimentally obtained CCE and misidentified hits in n-in-p devices with p-stop isolation pattern can be explained after analysis of the electric fields in dependence on the p-stop geometry and doping concentrations.The comparison of data and simulation results allows to limit the parameter space of the p-stop isolation technique which significantly affects the performance of irradiated n-in-p type silicon sensors.

High resistivity, chromium compensated gallium arsenide (HR-GaAs:Cr) has recently shown to be a promising sensor material for X-ray detectors due to its high resistivity, its fully active volume, the good electron transport properties and good absorption properties for photon energies up to around 40 keV. These properties make this material a favorable candidate for producing sensors for photon counting X-ray imaging detectors. Such detector systems have also gained increasing attention to be used for high flux applications as found at synchrotrons or in medical applications like computed tomography. Whereas other interesting high-Z materials such as CdTe have already been studied under high flux irradiation, the behavior of HR-GaAs:Cr under such conditions has yet to be investigated.

In this work, we study the performance of a 500 μm thick GaAs:Cr sensor, bump-bonded to Timepix readout electronics, with a main emphasis laid on the behavior under the irradiation of high X-ray fluxes using a monochromatic synchrotron beam. We find that, at high X-ray fluxes, the detector performance degrades, and that the dislocation network typically present in melt-grown GaAs influences the detection properties due to local variations of the charge transport properties. However, we also demonstrate that the high flux behavior can be substantially improved by optimized chip settings, namely by tuning the Timepix' preamplifier output pulse shape. In this way, the photon counting capabilities of the detector assembly are restored to a certain extent and it is possible to operate the detector assembly at impinging fluxes as high as 10¹⁰ s⁻¹mm⁻².

The upgrade of the CMS tracker for the HL-LHC is based on a binary readout scheme using the CMS Binary Chip (CBC2). The connectivity requirements of this flip-chip ASIC requires the use of high density interconnecting hybrids. Module integration studies indicated that a foldable flexible hybrid circuit results in an optimal module arrangement. A full module size HDI flexible hybrid was designed, integrating eight CBC2 ASICs. The hybrid is fitted with carbon fiber stiffeners and a sharp folding allows connecting the two strip sensor wirebond arrays. The front end circuit development was focused on the 2 Strip (2S) module electronics. This paper will present the implementation of the 2S front end electronics on a flexible substrate covering the mechanical and electrical properties of the assembly.

The instantaneous luminosity of the Large Hadron Collider (LHC) is being increased in several steps over the next 10 years to maximize its discovery potential for new physics. However, at a luminosity of twice the design luminosity of the LHC of 10³⁴ cm⁻² s⁻¹, the performance of the current CMS pixel detector is degraded by substantial deadtime caused by the readout chip (ROC). To make full use of the proton-proton collisions being provided by the LHC, CMS will replace its pixel detector during the extended winter shutdown in 2016-2017 with a new detector with four barrel layers and three disks in each endcap. Module production includes bump bonding, wire bonding, and gluing processes, as well as a series of functionality tests, calibrations and thermal cycling. One of the calibration steps is the X-ray calibration, which provides an absolute energy calibration of an internal calibration circuit. This circuit injects charge into the preamplifier to simulate a signal, and is used to define several parameters of the readout chip, including the threshold. Therefore, an absolute calibration is required in order to know the threshold in units of electrons. In this article, the barrel module assembly is explained, with a special focus on the X-ray calibration of the pixel detector.

The PERCIVAL ("Pixelated Energy Resolving CMOS Imager, Versatile and Large") is a collaboration of DESY, RAL/STFC, ELETTRA, and DLS to develop a monolithic active pixel sensor (MAPS) to provide a suitable detector for photon science for the photon energy regime between 250 eV and 1 keV. An important performance parameter is the spatial resolution which can be inferred from the Modulation Transfer Function (MTF). The MTF measures in optical systems the relative contrast of a pattern in function of the spatial frequency. With a back-thinned and back-illuminated PERCIVAL prototype chip, dedicated MTF evaluation data were taken at Elettra's TwinMic Beamline in March 2014 at a photon energy of 535 eV. We will present our MTF derivation approaches together with MTF results for 3 pixel types of the irradiated test sensor.

A prototype composed of four resistive plate chamber layers has been exposed to quasi-monoenergetic protons produced from a deuteron beam of varying energy (200 to 800 AMeV) in experiment S406 at GSI, Darmstadt, Germany. The aim of the experiment is to characterize the response of the prototype to protons in this energy range, which deposit from 1.75 to 6 times more energy than minimum ionizing particles. Each layer, with an active area of about 2000 × 500 mm², is made of modules containing the active gaps, all in multigap construction. Each gap is defined by 0.3 mm nylon mono-filaments positioned between 2.85 mm thick float glass electrodes. The modules are operated in avalanche mode with a non-flammable gas mixture composed of 90% C₂H₂F₄ and 10% SF₆. The signals are readout by a pick-up electrode formed by 15 copper strips (per layer), spaced at a pitch of 30 mm, connected at both sides to timing front end electronics. Results show an uniform efficiency close to 100% along with a timing resolution of around 60 ps on the entire 2000 × 500 mm² area.

ToPiX v4 is the prototype for the readout of the silicon pixel sensors for the Micro Vertex Detector of the PANDA experiment. ToPiX provides position, time and energy measurement of the incoming particles and is designed for the triggerless environment foreseen in PANDA. The prototype includes 640 pixels with a size of 100 × 100 μm², a 160 MHz time stamp distribution circuit to measure both particle arrival time and released energy (via ToT technique) and the full control logic. The ASIC is designed in a 0.13 μm CMOS technology with SEU protection techniques for the digital parts.

The increased luminosity of the HL-LHC will require more channels in the upgraded ATLAS Tracker, as a result of the finer detector segmentation. Thus, an upgraded and more efficient HV biasing of the sensors will also be needed and is among the many technological challenges facing the ATLAS Tracker Upgrade. A number of approaches, including the sharing of the same HV line among several sensors and suitable HV switches, along with their control circuitry are currently being investigated for this purpose. The proposed solutions along with latest test results and measurements will be described.

We have developed a novel detector concept based on Modified Internal Gate Field Effect Transistor (MIGFET) wherein a buried Modified Internal Gate (MIG) is implanted underneath a channel of a FET. In between the MIG and the channel of the FET there is a depleted semiconductor material forming a potential barrier between charges in the channel and similar type signal charges located in the MIG. The signal charges in the MIG have a measurable effect on the conductance of the channel. In this paper a double MIGFET pixel is investigated comprising two MIGFETs. By transferring the signal charges between the two MIGs Non-Destructive Correlated Double Sampling Readout (NDCDSR) is enabled.

The proposed MIG radiation detector suits particularly well for low-light-level imaging, X-ray spectroscopy, as well as synchrotron and X-ray Free Electron Laser (XFEL) facilities. The reason for the excellent X-ray detection performance stems from the fact that interface related issues can be considerably mitigated since interface generated dark noise can be completely avoided and interface generated 1/f and Random Telegraph Signal (RTS) noise can be considerably reduced due to a deep buried channel readout configuration.

Electrical parameters of the double MIGFET pixel have been evaluated by 3D TCAD simulation study. Simulation results show the absence of interface generated dark noise, significantly reduced interface generated 1/f and RTS noise, well performing NDCDSR operation, and blooming protection due to an inherent vertical anti-blooming structure. In addition, the backside illuminated thick fully depleted pixel design provides a homogeneous radiation entry window, low crosstalk due to lack of diffusion, and good quantum efficiency for low energy X-rays and NIR light.

These facts result in excellent Signal-to-Noise Ratio (SNR) and very low crosstalk enabling thus excellent X-ray energy and spatial resolution. The simulation demonstrates the charge to current conversion gain for source current readout to be 1.4 nA/e.

Timepix3 is a hybrid pixel detector readout chip. It features a data driven readout mode where the chip sends out a data packet containing pixel coordinate, time over threshold and time of arrival immediately after the hit is processed by the pixel. The maximum hit rate is 40 Mhits/cm²/s with a minimum time step in the arrival time measurement of 1.56 ns. The pixel matrix consist of 256 × 256 square pixels at a 55 μm pitch and the pixel front end noise is 61 e⁻ RMS. In this paper we present the first radiation measurements with Timepix3 bump bonded to a 300 μm thick silicon sensor. The chip is calibrated per pixel, using internal test pulses and the calibration is verified using X-ray fluorescence. The energy resolution, threshold dispersion and gain dispersion is measured. The energy resolution in time over threshold mode under normal operation conditions is 4.07 keV FWHM at 59.5 keV. At 10.5 keV an energy resolution of 0.72 keV FWHM was achieved in photon counting mode and in time over threshold mode, by optimizing the energy response, we achieved a 1.38 keV FWHM. We also investigate the time walk and present first results on using the time information for track reconstruction.

This paper presents the development of the GBTX radiation hard ASIC test bench. Developed for the LHC accelerator upgrade programs, the GBTX implements a bidirectional 4.8 Gb/s link between the radiation hard on-detector custom electronics and the off-detector systems. The test bench was used for functional testing of the GBTX and to evaluate its performance in a radiation environment, by conducting Total Ionizing Dose and Single-Event Upsets tests campaigns.

A number of studies have demonstrated that a room temperature proton irradiation may not be sufficient to provide an accurate estimation of the impact of the space radiation environment on detector performance. This is a result of the relationship between defect mobility and temperature, causing the performance to vary subject to the temperature history of the device from the point at which it was irradiated. Results measured using Charge Coupled Devices (CCD) irradiated at room temperature therefore tend to differ from those taken when the device was irradiated at a cryogenic temperature, more appropriate considering the operating conditions in space, impacting the prediction of in-flight performance. This paper describes the cryogenic irradiation, and subsequent annealing of an e2v technologies Swept Charge Device (SCD) CCD236 irradiated at −35.4°C with a 10 MeV equivalent proton fluence of 5.0 × 10⁸ protons · cm⁻². The CCD236 is a large area (4.4 cm²) X-ray detector that will be flown on-board the Chandrayaan-2 and Hard X-ray Modulation Telescope spacecraft, in the Chandrayaan-2 Large Area Soft X-ray Spectrometer and the Soft X-ray Detector respectively. The SCD is readout continually in order to benefit from intrinsic dither mode clocking, leading to suppression of the surface component of the dark current and allowing the detector to be operated at warmer temperatures than a conventional CCD. The SCD is therefore an excellent choice to test and demonstrate the variation in the impact of irradiation at cryogenic temperatures in comparison to a more typical room temperature irradiation.

Silicon detectors have gained in popularity since silicon became a widely used electronic semiconductor material. Silicon detectors are used in particle physics as well as imagers for pixel based detecting systems. Over the past twenty years a lot of experimental efforts have been focused on the effects of ionizing and non-ionizing radiation on silicon based detectors including charged coupled devices (CCDs). Some of this research was performed in the framework of high luminosity particle physics experiments, along with radiation hardness studies of basic semiconductors devices. The building blocks of silicon pixel detectors including CCDs are simple PIN or PN structures partially or totally depleted, or even MOS and APD (Avalanche PhotoDiode) structures. Bulk or surface defects considerably affect the transport of free carriers. We propose here guidelines for pixel design. The method takes into account the properties of defects and will be tested through two pixel structures. The electrical properties of defects can be reduced to basic parameters, which can be introduced in a standard simulation code to make predictive simulations. We include an analytical model for defect build up derived from isochronal annealing experiments. Studying pixels detectors with different geometrical structures and fabricated with various semiconducting materials is made possible with this method. Its purpose is to provide an alternative to tedious and extensive radiation tests on fabricated detectors. Predicting the pixel behaviour w.r.t. defect properties is necessary for the long-term reliability of detectors and for making them radiation hard. A general method for pixel design is introduced and we will show how it can be used for the design of alternative (germanium) pixels.

A high resolution TPC is the main option for a central tracking detector at the future International Linear Collider (ILC). It is planned that the MPGD (Micro Pattern Gas Detector) technology will be used for the readout. A Large Prototype TPC at DESY has been used to test the performance of MPGDs in an electron beam of energies up to 6 GeV. The first step in the technology development was to demonstrate that the MPGDs are able to achieve the necessary performance set by the goals of ILC. For this `proof of principle' phase, the ALTRO front-end electronics from the ALICE TPC was used, modified to adapt to MPGD readout. The proof of principle has been verified and at present further improvement of the MPGD technology is going on, using the same readout electronics. The next step is the 'feasibility phase', which aims at producing front-end electronics comparable in size (few mm²) to the readout pads of the TPC. This development work is based on the succeeding SALTRO16 chip, which combines the analogue and digital signal processing in the same chip. This paper summarizes the status of this work and discusses how the experiences made so far can be exploited to improve the final readout electronics.

A compact radiation-tolerant array optical transmitter module (ATx) is developed to provide data transmission up to 10Gbps per channel with 12 parallel channels for collider detector applications. The ATx integrates a Vertical Cavity Surface-Emitting Laser (VCSEL) array and driver circuitry for electrical to optical conversion, an edge warp substrate for the electrical interface and a micro-lens array for the optical interface. This paper reports the continuing development of the ATx custom package. A simple, high-accuracy and reliable active-alignment method for the optical coupling is introduced. The radiation-resistance of the optoelectronic components is evaluated and the inclusion of a custom-designed array driver is discussed.

The SLS detector group develops silicon hybrid detectors for X-ray applications used in synchrotron facilities all over the world. Both microstrip and pixel detectors with either single photon counting or charge integrating read out are being developed.

Low noise charge integrating detectors can be operated in single photon regime, i.e. with low fluxes and high frame rates in order to detect on average less than one photon per cluster of 2×2 pixels. In this case, the analog signal read out for each single X-ray provides information about the energy of the photon. Moreover the signal from neighboring channels can be correlated in order to overcome or even take advantage of charge sharing. The linear charge collection model describing microstrip detectors and large pixels is unsuitable for the calibration of small pitch pixel detectors due to the large amount of charge sharing occurring also in the corner region. For this reason, the linear charge collection model is extended to the case of small pixels and tested with monochromatic X-ray data acquired using the 25 μm pitch MÖNCH and the 75 μm pitch JUNGFRAU detectors. The successful outcome of the calibration of the MÖNCH detector is proven by the high energy resolution of the spectrum obtained by accumulating the counts from more than 6000 channels after the correction of the gain mismatches using the proposed model.

PIXIE III is the third generation of very large area (32 × 25 mm²) pixel ASICs developed by Pixirad Imaging Counters s.r.l. to be used in combination with suitable X-ray sensor materials (Silicon, CdTe, GaAs) in hybrid assemblies using flip-chip bonding. A Pixirad unit module based on PIXIE III shows several advances compared to what has been available up to now. It has a very broad energy range (from 2 to 100 keV before full pulse saturation), high speed (100 ns peaking time), high frame rate (larger than 500 fps), dead-time-free operation, good energy resolution (around 2 keV at 20 keV), high photo-peak fraction and sharp spectral separation between the color images. In this paper the results obtained with PIXIE III both in a test bench set-up as well in X-ray imaging applications are discussed.

A robust TDC with 4.8 ps bin width has been designed for harsh environments and high energy physics applications. The circuit uses resistive interpolation DLL with a novel dual phase detector architecture. This architecture improves startup- and recovery speed from single event strikes without control voltage ripple trade-off and requires no off-line calibrations. A 0.43 LSB DNL has been measured at a power consumption of 4.2 mW with an extended frequency range from 0.8 GHz to 2.4 GHz. The TDC has been processed in 40 nm CMOS technology.

The VISible imaging instrument VIS is one of two instruments on board the Euclid telescope. The focal plane consists of 36 CCD273-84 sensors manufactured by the e2v technologies. The sensors are designed to provide a maximum charge transfer efficiency (CTE) to minimize distortions to source shapes. Each sensor undergoes a rigorous on-ground electro-optical testing at several stages of the mission to ensure that strict requirements are met before the launch of the spacecraft. This paper summarizes the commissioning of the Euclid CCD273 testing facility at the Mullard Space Science Laboratory (MSSL), the lead institute for VIS . The testing bench supports the measurements of the point spread function (PSF), system noise and the flat field evaluation. Accurate spot measurements are extremely important for the precise modelling and general understanding of an instrument's PSF . We show the preliminary results of the optical characterization of the pre-development devices with a special interest in the measurements of the PSF at different illumination levels and in the VIS spectral range of 550–900 nm. Additionally, the influence of the on-ground testing environment and a dedicated readout electronics on the obtained images is taken into consideration.

Ra-223 Dichloride (Xofigo™) is a promising new radiopharmaceutical offering survival benefit and palliation of painful bone metastases in patients with hormone-refractory prostate cancer [1]. The response to radionuclide therapy and toxicity are directly linked to the absorbed radiation doses to the tumour and organs at risk respectively. Accurate dosimetry necessitates quantitative imaging of the biodistribution and kinetics of the radiopharmaceutical. Although primarily an alpha-emitter, Ra-223 also has some low-abundance X-ray and gamma emissions, which enable imaging of the biodistribution in the patient. However, the low spectral resolution of conventional gamma camera detectors makes in-vivo imaging of Ra-223 challenging. In this work, we present spectra and image data of anthropomorphic phantoms containing Ra-223 acquired with a small-pixel CdTe detector (HEXITEC) [2] with a pinhole collimator. Comparison is made with similar data acquired using a clinical gamma camera. The results demonstrate the advantages of the solid state detector in terms of scatter rejection and quantitative accuracy of the images. However, optimised collimation is needed in order for the sensitivity to rival current clinical systems.

As different dosage levels and administration regimens for this drug are explored in current clinical trials, there is a clear need to develop improved imaging technologies that will enable personalised treatments to be designed for patients.

CLIC is a world-wide collaboration to study the next ``terascale'' lepton collider, relying upon a very innovative concept of two-beam-acceleration. This accelerator, currently under study, will be composed of the subsequence of 21000 two-beam-modules. Each module requires more than 300 analogue and digital signals which need to be acquired and controlled in a synchronous way. CLIC-ACM (Acquisition and Control Module) is the 'generic' control and acquisition module developed to accommodate the controls of all these signals for various sub-systems and related specification in term of data bandwidth, triggering and timing synchronization. This paper describes the system architecture with respect to its radiation-tolerance, power consumption and scalability.

In the framework of the HL-LHC upgrade, the ATLAS experiment plans to introduce an all-silicon inner tracker to cope with the elevated occupancy.

To investigate the suitability of pixel sensors using the proven planar technology for the upgraded tracker, the ATLAS Planar Pixel Sensor R&D Project (PPS) was established comprising 19 institutes and more than 90 scientists. The paper provides an overview of the research and development project and highlights accomplishments, among them: beam test results with planar sensors up to innermost layer fluences (>10¹⁶ n_eq cm⁻²); measurements obtained with irradiated thin edgeless n-in-p pixel assemblies; recent studies of the SCP technique to obtain almost active edges by post-processing already existing sensors based on scribing, cleaving and edge passivation; an update on prototyping efforts for large areas: sensor design improvements and concepts for low-cost hybridisation; comparison between Secondary Ion Mass Spectrometry results and TCAD simulations. Together, these results allow an assessment of the state-of-the-art with respect to radiation-hard position-sensitive tracking detectors suited for the instrumentation of large areas.

The International Linear Collider (ILC) expresses a stringent requirement for high precision vertex detectors (VXD). CMOS pixel sensors (CPS) have been considered as an option for the VXD of the International Large Detector (ILD), one of the detector concepts proposed for the ILC. MIMOSA-31 developed at IPHC-Strasbourg is the first CPS integrated with 4-bit column-level ADC for the outer layers of the VXD, adapted to an original concept minimizing the power consumption. It is composed of a matrix of 64 rows and 48 columns. The pixel concept combines in-pixel amplification with a correlated double sampling (CDS) operation in order to reduce the temporal noise and fixed pattern noise (FPN). At the bottom of the pixel array, each column is terminated with a self-triggered analog-to-digital converter (ADC). The ADC design was optimized for power saving at a sampling frequency of 6.25 MS/s. The prototype chip is fabricated in a 0.35 μm CMOS technology. This paper presents the details of the prototype chip and its test results.

NEW is the first phase of NEXT-100 experiment, an experiment aimed at searching for neutrinoless double-beta decay. NEXT technology combines an excellent energy resolution with tracking capabilities thanks to a combination of optical sensors, PMTs for the energy measurement and SiPMs for topology reconstruction. Those two tools result in one of the highest background rejection potentials in the field. This work describes the tracking plane that will be constructed for the NEW detector which consists of close to 1800 sensors with a 1-cm pitch arranged in twenty-eight 64-SiPM boards. Then it focuses in the development of the electronics needed to read the 1800 channels with a front-end board that includes per-channel differential transimpedance input amplifier, gated integrator, automatic offset voltage compensation and 12-bit ADC. Finally, a description of how the FPGA buffers data, carries out zero suppression and sends data to the DAQ interface using CERN RD-51 SRS's DTCC link specification complements the description of the electronics of the NEW detector tracking plane.

MYTHEN is a single photon counting hybrid strip X-ray detector that has found application in x-ray powder diffraction (XRPD) experiments at synchrotrons worldwide. Originally designed to operate with hole collecting silicon sensors, MYTHEN is suited for detecting X-rays above 5 keV, however many PD beamlines have been designed for energies above 50 keV where silicon sensors have an efficiency of only few percent. In order to adapt MYTHEN to meet these energies the absorption efficiency of the sensor must be substantially increased.

Cadmium-Telluride (CdTe) has an absorption efficiency approximately 30 times that of silicon at 50 keV, and is therefore a very promising replacement candidate for silicon. Furthermore, the large dynamic range of the pre-amplifier of MYTHEN and its double polarity capability has enabled the characterisation of an electron collecting Schottky type CdTe sensor. A CdTe MYTHEN system has undergone a series of characterisation experiments including stress test of bias and radiation induced polarizations. The performance of this system will be presented and discussed.

AGIPD—(Adaptive Gain Integrating Pixel Detector) is a hybrid pixel X-ray detector developed by a collaboration between Deutsches Elektronen-Synchrotron (DESY), Paul-Scherrer-Institut (PSI), University of Hamburg and the University of Bonn. The detector is designed to comply with the requirements of the European XFEL. The radiation tolerant Application Specific Integrated Circuit (ASIC) is designed with the following highlights: high dynamic range, spanning from single photon sensitivity up to 10⁴ 12.5keV photons, achieved by the use of the dynamic gain switching technique using 3 possible gains of the charge sensitive preamplifier. In order to store the image data, the ASIC incorporates 352 analog memory cells per pixel, allowing also to store 3 voltage levels corresponding to the selected gain. It is operated in random-access mode at 4.5MHz frame rate. The data acquisition is done during the 99.4ms between the bunch trains. The AGIPD has a pixel area of 200× 200 μ m² and a 500μ m thick silicon sensor is used. The architecture principles were proven in different experiments and the ASIC characterization was done with a series of development prototypes. The mechanical concept was developed in the close contact with the XFEL beamline scientists and is now being manufactured. A first single module system was successfully tested at APS.

In this work, we present a front-end stage with signal compression capability to be used in detectors for the new European XFEL in Hamburg. This front-end is an alternative solution under study for the DEPFET Sensor with Signal Compression (DSSC) detection system for the European XFEL. The DEPFET sensor of the DSSC project has a high dynamic range and very good noise performance. The high gain for small collected charge and the compression for large signals will provide both desired features of single photon detection capability and wide dynamic range. However, manufacturing of the DEPFET sensor requires a sophisticated processing technology with a relatively long time fabrication process. Accordingly, an alternative solution, namely Day-0 solution, was introduced as an approach characterized not by the best performance of the DEPFET, but available in a shorter time to allow first beam tests and experiments. The alternative sensor is made of mini Silicon Drift Detector (mini-SDD) and the compression behavior is obtained from the front-end on the readout ASIC and not by the transistor integrated in the silicon sensor, as in the DEPFET. The first version of corresponding front-end of the Day-0 solution has been realized based on an input PMOSFET transistor placed on the readout chip. This simple front-end proved the working principle of the proposed compression technique and the desired noise performance. In this paper, an improved version of the Day-0 front-end is presented. In the new prototype, the current gain of the front-end stage has been increased by factor of 1.8, the total input capacitance (SDD+PMOSFET) has been reduced by factor of 2 with respect to the previous prototype and consequently the noise performance has been improved. Moreover, by introducing selectable extra branches in parallel with the main one, the compression behavior of the front-end can be tuned based on desired dynamic range.

Surface-barrier structures based on thin high-purity GaAs epilayers with a polyethylene converter were studied as fast neutron detectors. A continuous Schottky barrier with a large area of 5 × 5 mm² to the high-purity GaAs epilayers was fabricated using a Pt/TiN/Au metallization system. Results of measurement of electric parameters and α-particle spectra are presented. The fast neutron spectra from the ²⁴¹Am-Be source measured by the recoil proton method for various thicknesses of the polyethylene converter and various operating biases are shown as well. The proposed detectors have shown high neutron detection efficiency of 1.30·10⁻³ puls./neutr. and an acceptable signal-to-background ratio (at level of 50) as well as the capability to operate efficiently without any external bias.

The investigation of the pulse height distribution and X-ray sensitivity depending on the contact material on high resistive chromium compensated gallium arsenide (HR GaAs:Cr) sensors is presented. Some samples had Cr/Ni contacts made using electron-beam deposition and some samples had In additionally alloyed into the contacts. Three different configuration of sensors were investigated: Ni/Cr - HR GaAs:Cr – Cr/Ni, In/Ni/Cr - HR GaAs:Cr – Cr/Ni/In and In/Ni/Cr - HR GaAs:Cr – Cr/Ni. Depending on the type of sensor there are differences in both the X-ray sensitivity and pulse height distribution depending on X-ray intensity. Ni/Cr - HR GaAs:Cr – Cr/Ni – structures have shown sublinear sensitivity dependence to intensity, while In/Ni/Cr - HR GaAs:Cr – Cr/Ni/In are characterized by superlinear dependence holding everything else constant. The results and possible causes are discussed in this paper.

Photon-counting pixel detectors are now routinely used on synchrotron beamlines. Many applications benefit from their noiseless mode of operation, single-pixel point spread function and high frame rates. One of their drawbacks is a discontinuous detection area due to the space-consuming wirebonded connections of the readout chips. Moreover, charge sharing limits their efficiency and their energy discrimination capabilities. In order to overcome these issues the ESRF is developing SMARTPIX,a scalable and versatile pixel detector system with minimized dead areas and with energy resolving capabilities based on the MEDIPIX3RX readout chip. SMARTPIX exploits the through-silicon via technology implemented on MEDIPIX3RX, the active edge sensor processing developed in particular at ADVACAM, and the on-chip analog charge summing feature of MEDIPIX3RX. This article reports on system architecture, unit module structure, data acquisition electronics, target characteristics and applications.

The design and the preliminary measurements results of a multichannel, variable gain front-end electronics for luminosity detector at future Linear Collider are presented. The 8-channel prototype was designed and fabricated in a 130 nm CMOS technology. Each channel comprises a charge sensitive preamplifier with pole-zero cancellation circuit and a CR-RC shaper with 50 ns peaking time. The measurements results confirm full functionality of the prototype and compliance with the requirements imposed by the detector specification. The power consumption of the front-end is in the range 0.6–1.5 mW per channel and the noise ENC around 900 e ^- at 10 pF input capacitance.

Silicon microstrips are widely used in nuclear physics experiments when high granularity and high resolution is required (e.g. particle-particle correlation). In addition microstrip detectors are used in the field of X-ray detection for position resolved X-ray spectroscopy. In the framework of the construction of a novel Femtoscope ARray for Correlation and Spectroscopy, named FARCOS, we are performing a thorough characterization of the silicon detector layers in terms of the efficiency and charge collection properties as a function of the point of incidence and type of interaction. We have experimental evidence—as previously observed also in the literature for other strip detectors—that inter-strip incidence alters the signal shape not only for the trivial charge division but also affecting the shape of the induced signal on neighbor strips. The phenomenon can be more or less pronounced depending on the energy and ion type but it is always present. In order to surgically probe the response of the inter-strip region we tested the detector both in back and in front injection with an infrared pulsed laser at two different wavelengths (705 nm and 904 nm). Depending on the side of interaction, on the position of incidence and on the absorption length, the shapes of the induced signals are significantly altered and signals of opposite polarity or bipolar signals arise. In order to get a complete picture of the physical phenomena at the basis of the aforementioned behavior we performed detailed 3D device simulations with a custom semi-analytical code and compared the results with the experimental data. The paper focuses on the description of the experimental measurements and their exhaustive description and interpretation.

This paper will present the first results from irradiation tests performed on the ALICE TPC Readout Control Unit 2 (RCU2). The RCU2 is developed in order to double the readout speed with respect to the present RCU1, which then will fulfil the requirements for LHC RUN2. While the present RCU1 is based on an SRAM based FPGA, whose configuration memory has shown to be sensitive to single event upsets, the newly released Flash-based Smartfusion2 FPGA from Microsemi has been chosen for the RCU2.

The KM3NeT collaboration aims at the construction of a multi-km3 high-energy neutrino telescope in the Mediterranean Sea consisting of thousands of glass spheres, each of them containing 31 photomultipliers of small photocathode area. The readout and data acquisition system of KM3NeT has to collect, treat and send to shore, the enormous amount of data produced by the photomultipliers. For this purpose, 31 high-resolution time-interval measuring channels based on time to digital converter are implemented on the field-programmable gate arrays. Architectures with low resources occupancy are desirable allowing the implementation of other instrumentation, communication and synchronization systems on the same device. The required resolution to measure both, time of flight and time-stamp must be 1 ns. A 4-Oversampling technique with two high frequency clocks and an asymmetric FIFO memory is used to achieve this resolution. The proposed firmware has been developed in Xilinx Kintex-7.

The Cherenkov Telescope Array (CTA) will be the next generation ground-based observatory for cosmic gamma rays. The FlashCam camera for its mid-size telescope introduces a new concept, with a modest sampling rate of 250 MS/s, that enables a continuous digitization as well as event buffering and trigger processing using the same front-end FPGAs. The high performance Ethernet-based readout provides a dead-time free operation for event rates up to 30 kHz corresponding to a data rate of 2.0 GByte/s sent to the camera server. We present the camera design and the current status of the project.

The CLARO-CMOS is a prototype ASIC designed for fast photon counting with multi-anode photomultiplier tubes (MaPMT). The CLARO features a 5 ns peaking time, a recovery time to baseline smaller than 25 ns, and a power consumption of less than 1 mW per channel. The chip was designed in 0.35 μm CMOS technology, and was tested for radiation hardness with neutrons up to 10¹⁴ 1 MeV n_eq/cm², X-rays up to 40 kGy and protons up to 76 kGy. Its capability to read out single photons at high rate from a Hamamatsu R11265 MaPMT, the baseline photon detector for the LHCb RICH upgrade, was demonstrated both with test bench measurements and with actual signals from a R11265 MaPMT. The presented results allowed CLARO to be chosen as the front-end readout chip in the upgraded LHCb RICH detector.

The PEALL4 chip is a Power Efficient And Low Latency 4-channels, 12-bit and 40-MSPS successive approximation register (SAR) ADC. It was designed featuring a very short latency time in the context of ATLAS Liquid Argon Calorimeter phase I upgrade. Moreover this design could be a good option for ATLAS phase II and other High Energy Physics (HEP) projects. The full functionality of the converter is achieved by an embedded high-speed clock frequency conversion generated by the ADC itself. The design and testing results of the PEALL4 chip implemented in a commercial 130nm CMOS process are presented. The size of this 4-channel ADC with embedded voltage references and sLVS output serializer is 2.8x3.4 mm². The chip presents a short latency time less than 25 ns defined from the very beginning of the sampling to the last conversion bit made available. A total power consumption below 27mW per channel is measured including the reference buffer and the sLVS serializer.

The readout chain of the DSSC 1M pixel detector currently built at DESY, Hamburg for the European X-Ray Free Electron Laser is described. The system operates in pulsed operation mode comparable to the new ILC. Each 0.1 seconds 800 images of 1M pixels are produced and readout by the DSSC DAQ electronics. The total data production rate of the system is about 134 Gbit/s. In order to deal with the high data rates, latest technology components like the Xilinx Kintex 7 FPGA are used to implement fast DDR3-1600 image buffers, high speed serial FPGA to FPGA communication and 10 GB Ethernet links concentrated in one 40 Gbit/s QSFP+ transceiver.

PET imaging is a non-invasive technique for particle range verification in proton therapy. It is based on measuring the β⁺ annihilations caused by nuclear interactions of the protons in the patient. In this work we present measurements for proton range verification in phantoms, performed at the CNAO particle therapy treatment center in Pavia, Italy, with our 10 × 10 cm² planar PET prototype DoPET. PMMA phantoms were irradiated with mono-energetic proton beams and clinical treatment plans, and PET data were acquired during and shortly after proton irradiation. We created 1-D profiles of the β⁺activity along the proton beam-axis, and evaluated the difference between the proximal rise and the distal fall-off position of the activity distribution. A good agreement with FLUKA Monte Carlo predictions was obtained. We also assessed the system response when the PMMA phantom contained an air cavity. The system was able to detect these cavities quickly after irradiation.

The New Small Wheel (NSW) is an upgrade for the ATLAS detector to provide enhanced triggering and reconstruction of muons in the forward region. The large LV power demands of the NSW necessitate a point-of-load architecture with on-detector power conversion. The radiation load and magnetic field of this environment, while significant, are nevertheless still in the range where commercial-off-the-shelf power devices may suffice.

We present studies on the radiation-hardness and magnetic-field tolerance of several candidate buck converters and linear regulators. Device survival and performance are characterized when exposed to gamma radiation, neutrons, protons and magnetic fields.

The MicroTCA and AdvancedTCA industry standards are candidate modular electronics platforms for the upgrade of the current generation of high energy physics experiments at CERN. The PH-ESE group at CERN launched an xTCA evaluation project with the aim of performing technical evaluations and providing support for commercially available components. Over the past years, different equipment from different vendors has been acquired and evaluated. This paper summarizes our evaluation results of commercial MicroTCA and AdvancedTCA equipment. Special emphasis is put on the component requirements to be defined in view of future equipment procurement. Customized prototypes developed according to these generic specifications are presented for the first time.

After Phase-II upgrades in 2022, the data output from the LHC ATLAS Tile Calorimeter will increase significantly. ARM processors are common in mobile devices due to their low cost, low energy consumption and high performance. It is proposed that a cost-effective, high data throughput Processing Unit (PU) can be developed by using several consumer ARM processors in a cluster configuration to allow aggregated processing performance and data throughput while maintaining minimal software design difficulty for the end-user. This PU could be used for a variety of high-level functions on the high-throughput raw data such as spectral analysis and histograms to detect possible issues in the detector at a low level. High-throughput I/O interfaces are not typical in consumer ARM System on Chips but high data throughput capabilities are feasible via the novel use of PCI-Express as the I/O interface to the ARM processors. An overview of the PU is given and the results for performance and throughput testing of four different ARM Cortex System on Chips are presented.

The problem of pulsed current signals in capacitor type sensors, due to drifting surface charge domain is considered for the analysis of the operational characteristics in photo- and particle-detectors. In this article, the models of the formation of the pulsed currents have been analyzed in vacuum and dielectric filled capacitor-like detectors. Injected charge drift regimes such as Shockley-Ramo's-type (large charge drift) and free flight within Coulomb's force field (small charge drift) are discussed. It has been shown that solutions of the injected charge drift in the vacuum gap capacitor can be employed to emulate charge drift over free path in dynamic solution of the problem with scattering. Pulsed current signals and charge drift in the detectors of the capacitor filled with dielectric type have been analyzed, where the bipolar charge injection and various drift regimes appear. The bipolar carrier drift transformation to a monopolar one is considered, after either electrons or holes, injected within the material, reach the external electrode. The impact of the dynamic capacitance and load resistance in the formation of drift current transients is highlighted. It has been illustrated that the synchronous action of carrier drift, trapping, generation and diffusion can lead to a vast variety of possible current pulse waveforms.

The Level-1 trigger for muons of the ATLAS experiment is based on trigger chambers with excellent timing resolution which identify muons coming from a particular beam crossing. To cope with the stringent constraint on the trigger rates expected during phase II of the LHC, the so-called High-Luminosity LHC, it is proposed to include precision tracking chambers in the Level-1 muon trigger for improving the transverse momentum resolution. The rate of a single muon trigger with a transverse momentum threshold of 20 GeV is estimated to be reduced by about a factor of two over the entire pseudorapidity region by introducing the proposed upgrade. An architecture of the electronics includes an additional priority readout chain, which is independent of the standard and asynchronous readout. A demonstrator of the frontend electronics has been developed and an initial test based on cosmic muons shows position resolution measurements consistent with the simulation.

A prototype Liquid-argon Trigger Digitizer Board (LTDB), called the LTDB Demonstrator, has been developed to demonstrate the functions of the ATLAS Liquid Argon Calorimeter Phase-I trigger electronics upgrade. Forty Analog-to-Digital converters and four FPGAs with embedded multi-gigabit-transceivers on each Demonstrator need high quality clocks. A clock distribution system based on commercial components has been developed for the Demonstrator. The design of the clock distribution system is presented. The performance of the clock distribution system has been evaluated. The components used in the clock distribution system have been qualified to meet radiation tolerance requirements of the Demonstrator.

The RPC muon detector of the CMS experiment at the LHC (CERN, Geneva, Switzerland) is equipped with a Gas Gain Monitoring (GGM) system. A report on the stability of the system during the 2011-2012 data taking run is given, as well as the observation of an effect which suggests a novel method for the monitoring of gas mixture composition.

CMOS image sensors are widely used in several applications such as mobile handsets webcams and digital cameras among others. Furthermore they are available across a wide range of resolutions with excellent spectral and chromatic responses. In order to fulfill the need of cheap systems as beam monitors and high resolution image sensors for scientific applications we exploited the possibility of using commercial CMOS image sensors as X-rays and proton detectors. Two different sensors have been mounted and tested. An Aptina MT9v034, featuring 752 × 480 pixels, 6μm × 6μm pixel size has been mounted and successfully tested as bi-dimensional beam profile monitor, able to take pictures of the incoming proton bunches at the DeFEL beamline (1–6 MeV pulsed proton beam) of the LaBeC of INFN in Florence. The naked sensor is able to successfully detect the interactions of the single protons. The sensor point-spread-function (PSF) has been qualified with 1MeV protons and is equal to one pixel (6 mm) r.m.s. in both directions. A second sensor MT9M032, featuring 1472 × 1096 pixels, 2.2 × 2.2 μm pixel size has been mounted on a dedicated board as high-resolution imager to be used in X-ray imaging experiments with table-top generators. In order to ease and simplify the data transfer and the image acquisition the system is controlled by a dedicated micro-processor board (DM3730 1GHz SoC ARM Cortex-A8) on which a modified LINUX kernel has been implemented. The paper presents the architecture of the sensor systems and the results of the experimental measurements.

In this work we propose a 3D monolithically stacked, multi-layer detectors based on CMOS Active Pixel Sensors (APS) layers which allows at the same time accurate estimation of the impact point and of the incidence angle an ionizing particle. The whole system features two fully-functional CMOS APS matrix detectors, including both sensing area and control/signal elaboration circuitry, stacked in a monolithic device by means of Through Silicon Via (TSV) connections thanks to the capabilities of the CMOS vertical scale integration (3D-IC) 130 nm Chartered/Tezzaron technology. In order to evaluate the suitability of the two layer monolithic active pixel sensor system to reconstruct particle tracks, tests with proton beams have been carried out at the INFN LABEC laboratories in Florence (Italy) with 3 MeV proton beam.

In particle-astrophysics large liquid xenon detectors are used for Dark Matter Search, and these detectors seem continuously to grow in target mass. Specially developed PMTs fulfill all the requirements for an efficient light read out, however, as the number of PMTs increases the connection of the signal and HV lines to the outside world becomes more problematic; feedthroughs and connectors are difficult to realize within the limited space of a detector, and coaxial cables can trap many impurities afterwards to be released into the clean liquid. We propose the use of flexible Kapton strip lines combining the signals and anode HV from 32 PMTs in one 2" wide, 0.004" thick band. We compared a 1.5 m long, unshielded strip line with coaxial cable of the same length. Minimal changes to the base are required without any risk of additional impurities or radio activity. The quality of the signal is compatible.

The HV connections can be easily realized without additional capacitors on the base by grounding the second but last dynode. This reduces the voltage on the anode to less than 300 V, compatible with the strip line specifications. All the cathodes are connected to one common negative HV. Such a scheme does not cause cross talk and preserves the possibility to adjust the gain of each PMT separately.

Persistence of an X-ray image intensifier with a YAG (P46, Y₃Al₅O₁₂:Ce³⁺) phosphor in the output window was examined using X-ray pulses from a storage ring and a high-speed CMOS camera. Because of the fast decay of the YAG fluorescence (60 ns), persistence of CsI:Na⁺ in the input window dominates the decay of intensity of the image intensifier. As reported before, persistence of CsI:Na⁺ had two major components when fitted with two exponential functions, a fast one around 600 ns and a slow one about 7 μs. In addition, it was found that a slower component, which is small but takes tens of microseconds to decay, also exists. Thus, this detector should be used with caution at a time resolution higher than about 50 μs when high accuracy of measurement is required.

The Recycler Electron Cooler (REC) was the first cooler working at a relativistic energy ( γ = 9.5). It was successfully developed in 1995-2004 and was in operation at Fermilab in 2005–2011, providing cooling of antiprotons in the Recycler ring. After introducing the physics of electron cooling and the REC system, this paper describes measurements carried out to tune the electron beam and optimize its cooling properties. In particular, we discuss the cooling strategy adopted for maximizing the collider integrated luminosity.