Single and double ionization of He by slow protons and antiprotons

Journal Article · Wed Jun 01 00:00:00 EDT 1994 · Physical Review A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.49.R4281· OSTI ID:7116615

Kimura, M ^[1]; Shimamura, I ^[2]; Inokuti, M ^[3]

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1. Argonne National Laboratory, Argonne, Illinois 60439 and Department of Physics, Rice University, Houston, Texas 77251 (United States)
2. Institute of Physical and Chemical Research (RIKEN), Wako, Saitama 351-01 (Japan)
3. Argonne National Laboratory, Argonne, Illinois 60439 (United States)

Double and single ionization of He by proton ([ital p]) and antiproton ([ital [bar p]]) impact in the energy region below 50 keV is studied theoretically within a molecular picture. As the energy decreases, the ratio of the double- to single-ionization cross section is found to increase for [ital [bar p]] impact and to decrease to [ital p] impact in agreement with recent measurements. For [ital p] impact, the dominant mechanism for double ionization at the lower energies seems to be sequential ladder climbing by the two electrons through various excited channels. For [ital [bar p]] impact, in contrast, the approaching negative charge distorts the He electron cloud toward the other side of the nucleus and decreases the electron binding energies. These effects enhance the important role of electron-electron, interactions, increasing double ionization.

• DOE Contract Number: W-31-109-ENG-38
• OSTI ID: 7116615
• Journal Information: Physical Review A; (United States), Vol. 49:6; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ANTIPROTONS
ION-ATOM COLLISIONS
HELIUM
PROTONS
CROSS SECTIONS
ELECTRON-ELECTRON INTERACTIONS
ENERGY DEPENDENCE
IONIZATION
KEV RANGE 10-100
ANTIBARYONS
ANTIMATTER
ANTINUCLEI
ANTINUCLEONS
ANTIPARTICLES
ATOM COLLISIONS
BARYONS
COLLISIONS
ELEMENTARY PARTICLES
ELEMENTS
ENERGY RANGE
FERMIONS
FLUIDS
GASES
HADRONS
INTERACTIONS
ION COLLISIONS
KEV RANGE
LEPTON-LEPTON INTERACTIONS
MATTER
NONMETALS
NUCLEI
NUCLEONS
PARTICLE INTERACTIONS
RARE GASES
664300* - Atomic & Molecular Physics- Collision Phenomena- (1992-)
664500 - Special Atoms & Molecules- (1992-)