Table of contents

Dissociation channels induced by sequential UV multiphoton absorption of vapour phase fluorene cation is investigated using energy selective ToF mass spectrometer. Neutral fluorene molecule is ionized by resonantly enhanced multiphoton absorption and dissociated in the same photon field. The main goal of this experiment is to determine the rate constants of statistical dissociation channels of PAH cations for a wide range of internal energies.

In the present study will be investigated the ionization of isolated pyrimidine molecules induced by ions. The total and differential cross section have been computed with a quantum mechanical method within the continuum distorted wave-eikonal initial state (CDW-EIS) approximation. A comparison with the available data is presented.

We present studies of low-energy resonance electron attachment in a series of 5-membered heterocyclic rings under gas-phase conditions by means of electron transmission spectroscopy and dissociative electron attachment spectroscopy.

The purpose of the present work is to emphasize the need for realistic modeling of the biological medium when studying the transport of protons in living matter at the very small scale. In this context, we have used the TILDA-V Monte Carlo track-structure code to simulate the irradiation of single cells with proton beams over the energy range of 10 keV – 100 MeV.

Screened independent atom model calculations for the net ionization of complex biomolecules bom-barded by energetic protons are presented. Scaling relations are examined and a simple parametrization of the cross section results in terms of an analytical formula is suggested.

We study the ionization and fragmentation of tetrahydrofuran (THF) and hydrated THF clusters induced by low-energy (65 eV) electron-collision using an (e, 2e + ion) triple coincidence method. The momentum vectors and the kinetic energies for all three final-state charged particles are determined. The ionic fragments are identified from the measured ion time-of-flight spectra. The influence of the water environment on the biomolecule is investigated with the ion fragment correlated binding energy spectra and triple-differential cross sections as well as ab-initio dynamical calculations.

The electronic structure and the fragmentation dynamics of a series of isolated cyclic-dipeptides (cyclo-Ala-Ala; cyclo-Gly-Ala; cyclo-Gly-Gly) have been studied by mass spectrometry, photoemission and photoelectron-photoion coincidence spectroscopy.

The present study aims at scrutinizing at the nanometer scale the radiodosimetry endpoints induced by ion beams in a realistic biological medium. In this context, self-consistent quantum mechanical modeling of the ionization and the electron capture processes are reported within the continuum distorted wave-eikonal initial state (CDW-EIS) framework for both isolated water molecules and DNA components impacted by ions.

This study focuses on the electron emission induced by He ions on water molecule. In this context, the ionization and the electron capture processes will be investigated using a quantum mechanical description within the continuum distorted wave-eikonal initial state (CDW-EIS) approximation.

Protonated uracil (m/z 113) and uridine (m/z 245) were exposed to synchrotron radiation in the photon energy range of 4.5 to 9 eV. The yield of various fragments as a function of photon energy shows maxima that can be attributed to excited electronic states and compared to calculated vertical excitation energies. For the nucleoside uridine, much less fragments were observed, indicating a stabilization of the nucleobase through the attached sugar molecule.