Electron interactions with molecules of biological interest

Tesis doctoral inédita. Universidad Autónoma de Madrid, Facultad de Ciencias. Fecha de lectura: 13-12-2013In this thesis, electron collisions with molecules of biological interest are investigated. The main focus lies on the conduction of total scattering cross section and electron energy loss measurements at different apparatuses and energy ranges and includes the construction, testing and start of operation of a new experimental device using a strong magnetic field for confining the electron beam during the cross section measurements. Furthermore, theoretical electron-molecule cross sections are derived from the optical potentials of the atomic constituents taking into account intramolecular screening effects. The scattering targets thus studied in the general energy range of interest (1–10 000 eV) are argon, methane, ethylene, tetrahydrofuran, p-xylene, pyrimidine, and pyrazine. Based on the original data obtained and aided by a critical analysis and comparison to other relevant results, carefully selected and self-consistent electron collisional data sets can be recommended for some of the molecules mentioned. They are compiled from the most representative and accurate sources for each type of interaction parameter in order to provide a complete reference describing electron scattering from the respective molecules in the energy range 1–10 000 eV. The tabulated data include integral partial cross sections for the different interaction processes, differential cross sections for elastic scattering and also energy loss distribution functions for the same range of incident energies. In addition, an empirical approximation to inelastic differential cross sections is proposed. Finally, a custom-programmed molecular-level Monte Carlo code, the Low- Energy Particle Track Simulation, directly uses the data base generated for the simulation of realistic macroscopic situations such as electron transport through gases or medical radiation applications, adding practical utility to the scientific results obtained