title: Differential and total (e,2e) cross sections of simple polyatomic molecules.
abstract: In this paper, we present a theoretical approach to calculate differential and total ionization cross sections of polyatomic molecules by fast electron impact. More exactly, we have studied the ionization of ammonia (NH(3)) and methane (CH(4)) molecules, and previous results concerning the H(2)O molecule ionization are reported for comparison. The calculations are performed in the distorted wave Born approximation without exchange by employing the independent electron model. The molecular target wave functions are described by linear combinations of atomic orbitals. To describe the interaction between the inactive target electrons and the slow ejected electron, we have introduced a distortion via an effective potential calculated for each molecular orbital. The present theoretical calculations agree well with a large set of existing experimental data in terms of multiple differential and total cross sections.
authors.affiliation: Laboratoire de Physique Moléculaire et des Collisions, Institut de Physique, 1 boulevard Arago, Technopôle 2000, 57078 Metz, Cedex 3, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Champion
authors.forename: Jocelyn
authors.initials: J
authors.lastname: Hanssen
authors.forename: Paul-Antoine
authors.initials: PA
authors.lastname: Hervieux