title: Cross section calculations for electron scattering from DNA and RNA bases.
abstract: Differential and integral cross sections for elastic electron collisions with uracil, cytosine, guanine, adenine and thymine have been calculated using the independent atom method with a static-polarization model potential for incident energies ranging from 50 to 4000 eV. Total cross sections for single electron-impact ionization of selected DNA and RNA bases have also been calculated with the binary-encounter-Bethe model from the ionization threshold up to 5000 eV. Cross sections within the investigated energy range, can be related to the molecular symmetry, the number of target electrons and molecular size; elastic and ionization processes are most efficient for guanine and adenine molecules, while the lowest cross sections were obtained for the uracil molecule. The ionization cross sections for cytosine, thymine, adenine and guanine are compared with those recently obtained with a semi-classical and binary-encounter-Bethe formalisms. No theoretical and experimental data for elastic electron scattering from DNA and RNA bases are available, but comparisons with calculations for molecules of similar size and geometry allows the validity of the theoretical approach to be verified.
authors.affiliation: Groupe des Instituts de Recherche en Santé du Canada en Sciences des Radiations, Faculté de Médecine, Université de Sherbrooke, 3001 12 Avenue Nord, Sherbrooke, Québec, J1H 5N4, Canada. Pawel.Mozejko@Usherbrooke.ca
authors.forename: Paweł
authors.initials: P
authors.lastname: Moejko
authors.forename: Léon
authors.initials: L
authors.lastname: Sanche
mesh_terms: D001665:Binding Sites; D003198:Computer Simulation; D004247:DNA / Q000737:chemistry* / Q000528:radiation effects*; D004583:Electrons; D018499:Linear Energy Transfer; D008958:Models, Molecular; D009690:Nucleic Acid Conformation / Q000528:radiation effects; D009711:Nucleotides / Q000737:chemistry* / Q000528:radiation effects*; D012313:RNA / Q000737:chemistry* / Q000528:radiation effects*; D012542:Scattering, Radiation
chemical_list: D009711:Nucleotides; D012313:RNA; D004247:DNA