Cross sections for ionization of gases by 5-4000-keV protons and for electron capture by 5-150-keV protons

• Published in: Physical review. A, General physics Vol. 28; no. 6; pp. 3244 - 3257
• Main Authors: RUDD, M. E, DUBOIS, R. D, TOBUREN, L. H, RATCLIFFE, C. A, GOFFE, T. V
• Format: Journal Article
• Language: English
• Published: New York, NY American Institute of Physics 01-12-1983
• Subjects: Atomic and molecular collision processes and interactions; Atomic and molecular physics; Charge transfer; Exact sciences and technology; Physics; Methane; Noble gas Atoms; Oxygen Molecules; Hydrogen Molecules; Carbon dioxide; Atom ion collision; Experimental study; Hydrogen Atomic ions; Inorganic compound; Positive ion; Electron capture; Diatomic molecule; Intermediate energy; Nitrogen Molecules; High energy; Ionization; Carbon monoxide; Total cross section; Triatomic molecule; Ion molecule collision; Organic compounds
• ISSN: 0556-2791
• DOI: 10.1103/PhysRevA.28.3244

Using the parallel-plate-capacitor method and a capacitance manometer to determine pressures, total cross sections for the production of positive and negative charges were measured for 5-4000-keV-proton impact on He, Ne, Ar, Kr, H2, N2, CO, O2, CH4, and CO2. From these, ionization and electron-capture cross sections were obtained and fitted to semiempirical equations describing the energy dependence in terms of a few parameters. At high energies very good agreement is obtained in the comparison of the ionization cross sections to earlier proton- and electron-impact measurements and with theoretical treatments where they are available, but discrepancies exist for some targets at low energy. Above 10 keV the electron-capture cross sections are in agreement with earlier work for all the targets except CO and CH4 for which they are (20-40) percent higher.