Charge-changing cross sections for 1--70-keV H/sup +/ and H/sup 0/ in collisions with calcium and strontium metal vapors

Journal Article · Thu Sep 01 04:00:00 EDT 1983 · Phys. Rev. A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.28.1315· OSTI ID:5469739

Mayo, M; Stone, J A; Morgan, T J

Absolute electron-transfer cross sections have been measured for H/sup +/ and H/sup 0/ in collisions with Ca and Sr metal vapor targets for energies between 1 and 70 keV. The measurements include cross sections for single- and double-electron capture by H/sup +/ and single-electron capture and loss by H/sup 0/. The single-electron capture cross section for H/sup +/ incident has been calculated using the binary-encounter approximation, and agrees with experiment to within a factor of 2 for energies between 2 and 70 keV. The electron-detachment cross section for H/sup -/ in collisions with Ca and Sr is determined from the present measured data and previously measured charge-state equilibrium fractions. The high- and low-energy structure in the cross sections for single- and double-electron capture by H/sup +/ are discussed in terms of the importance of inner-shell capture at high energies and a molecular picture at low energies, and the cross sections are compared to those for Mg and Ba targets published in a previous paper. The cross section for single-electron capture by H/sup 0/ rises at low energies; that for electron detachment from H/sup -/ decreases at low energies in agreement with theoretical predictions of Olson and Liu. This situation is discussed as the mechanism responsible for large negative-ion equilibrium yields at low energies for alkaline-earth targets.

• Research Organization: Physics Department, Wesleyan University, Middletown, Connecticut 06457
• OSTI ID: 5469739
• Journal Information: Phys. Rev. A; (United States), Journal Name: Phys. Rev. A; (United States) Vol. 28:3; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ALKALINE EARTH METALS
ATOM COLLISIONS
ATOM-ATOM COLLISIONS
CALCIUM
CATIONS
CHARGE EXCHANGE
CHARGED PARTICLES
COLLISIONS
CROSS SECTIONS
DATA
ELECTRON DETACHMENT
ELECTRON LOSS
ELEMENTS
ENERGY RANGE
EXPERIMENTAL DATA
HYDROGEN
HYDROGEN IONS
HYDROGEN IONS 1 PLUS
INFORMATION
ION COLLISIONS
ION-ATOM COLLISIONS
IONS
KEV RANGE
KEV RANGE 01-10
KEV RANGE 10-100
METALS
NONMETALS
NUMERICAL DATA
STRONTIUM