Mesure de sections efficaces absolues vibrationnelles pour la collision d’électrons de basse énergie (1-19 eV) avec le tétrahydrofurane (THF) condensé

This master’s thesis is a study of interactions probabilities (cross sections) of low-energy electrons with an important biomolecule. The studied molecule is tetrahydrofuran (THF) which is a good model for the DNA backbone constituent deoxyribose. Knowing the important quantity of secondary electrons generated by the radiations passage through the biological matter and knowing that these low-energy electrons are responsible for the majority of the energy deposited, the study of their interactions with DNA constituents becomes rapidly important. Cross sections measurements are performed with a high-resolution electron energy loss spectrometer. The electron energy loss spectra obtained from this spectrometer allow cross sections calculations for each vibration mode as a function of electron incident energy. The article presented in this master thesis describes in details the experimental methods, it presents energy loss spectra and it shows and discusses results obtained in this project. The energy dependence of the cross sections allows the observation of multiple resonances in many vibration modes of THF. Effectively, this study allows the energy localisation of 4 resonances, which have all been confirmed by previous experimental and theoretical studies on the electron-THF collisions. Additionally, these resonances have never been observed simultaneously in the same study and the resonance found at low incident energy has never been observed with as much intensity as this present work. This study allowed a better understanding of the fundamental processes occurring in collisions of low-energy electrons with THF. The cross sections values are highly prized by theorists and they are essential for Monte Carlo simulations. These values will be used in models for energy distribution and deposition in biological matter at nanoscopic scales, thereby they will eventually improve the efficiency of radiotherapeutic modalities.

Name thesis:degree_name

M. Sc.

Level thesis:degree_level

Maîtrise

Discipline thesis:degree_discipline

Sciences des radiations et imagerie biomédicale

Grantor dc:publisher

Université de Sherbrooke

Year dc:date.issued

2016

Author dc:creator

• Lemelin, Vincent

Advisor dc:contributor.advisor

• Sanche, Léon

• Sections efficaces
• Tétrahydrofurane
• Résonances d'électrons de basse énergie
• Cross sections
• Électrons de basse énergie
• Tetrahydrofuran
• Électrons secondaires
• Secondary electron
• Low-energy electron resonances

Language dc:language.iso

fr, en

Handle dc:identifier.uri

http://hdl.handle.net/11143/9467

OAI identifier oai:identifier

oai:usherbrooke.scholaris.ca:11143/9467