Multiple ionization of He, Ne, and Ar by fast protons and antiprotons

Journal Article · Thu Oct 15 00:00:00 EDT 1987 · Phys. Rev. A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.36.3612· OSTI ID:6015549

Andersen, L H; Hvelplund, P; Knudsen, H; Moller, S P; Sorensen, A H; Elsener, K; Rensfelt, K; Uggerhoj, E

Single and multiple ionization of He, Ne, and Ar has been studied experimentally by impact of fast protons and antiprotons. The single-ionization cross sections obtained with protons and antiprotons are found to be the same. The double-ionization cross sections obtained with antiprotons, however, are much larger than those obtained with protons at equal velocity. This difference is found for all three gases but the effect is largest for He and Ne, where the difference is about a factor of 2 at 1 MeV/amu. The difference is discussed in terms of interference between two collision mechanisms which both result in double-electron escape. Experimental information on the magnitude of the interference term is obtained by inclusion of double-ionization data, partly obtained in this work, for fast electron and ..cap alpha..-particle impact. For triple ionization of Ne, we also find that antiprotons yield much larger cross sections than protons do. Identical cross sections, however, are found for triple ionization of Ar with protons and antiprotons. This is believed to be due to the fact that triple ionization of Ar is mainly a consequence of a single vacancy produced in an inner shell followed by electronic rearrangement. This observation supports the interpretation that the observed charge effect is due to an interference effect in the outermost shell.

• Research Organization: Institute of Physics, University of Aarhus, DK-8000 Aarhus C, Denmark
• OSTI ID: 6015549
• Journal Information: Phys. Rev. A; (United States), Vol. 36:8
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ARGON
ION-ATOM COLLISIONS
HELIUM
HYDROGEN IONS 1 PLUS
NEON
ANTIPROTONS
COMPARATIVE EVALUATIONS
CROSS SECTIONS
EXPERIMENTAL DATA
IONIZATION
KEV RANGE 100-1000
MEV RANGE 01-10
MULTICHARGED IONS
ANTIBARYONS
ANTIMATTER
ANTINUCLEI
ANTINUCLEONS
ANTIPARTICLES
ATOM COLLISIONS
BARYONS
CATIONS
CHARGED PARTICLES
COLLISIONS
DATA
ELEMENTARY PARTICLES
ELEMENTS
ENERGY RANGE
FERMIONS
FLUIDS
GASES
HADRONS
HYDROGEN IONS
INFORMATION
ION COLLISIONS
IONS
KEV RANGE
MEV RANGE
NONMETALS
NUCLEI
NUCLEONS
NUMERICAL DATA
RARE GASES
640304* - Atomic
Molecular & Chemical Physics- Collision Phenomena