Experimental electron-detachment cross sections for collisions of O2− with N2 molecules in the energy range 50–7000 eV

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 (O2-) 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 O2- beam after interaction with N2 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 (N2+, N+) to the primary O2- beam intensity.