Authors: Mendes, M.; Guerra, C.; Lozano, A., I; Rojo, D.; Oller, J. C.; Limao-Vieira, P.; Garcia, G.

Contribution: Article


Publication date: 2019/06/24

DOI: 10.1103/PhysRevA.99.062709

Abstract: An experimental setup has been implemented to obtain absolute total electron detachment cross sections and relative ionization cross sections in the energy range 50-7000 eV in gas-phase collisions between anionic beams and neutral molecular targets. The primary anionic beam (O-2(-)) is produced through a pulsed hollow cathode discharge-induced plasma, deflected and focused towards the collision region where the molecular target is maintained at a well-known pressure. Electron detachment cross sections are measured from the attenuation of the O-2(-) beam after interaction with N-2 molecules confined in a gas cell. Negative and positive fragment ions produced during the collisions are extracted and mass analyzed by time-of-flight mass spectrometry. Relative ionization cross sections are derived from the ratio of the measured positive ion fragment intensities (N-2(+), N+) to the primary O-2(-) beam intensity.