Single-electron-capture cross sections for 1--10-keV Li/sup +/ ions in alkaline-earth vapors

Journal Article · Thu Aug 01 04:00:00 EDT 1985 · Phys. Rev. A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.32.784· OSTI ID:5481355

Coggiola, M J; Bae, Y K; Peterson, J R

Total charge-neutralization cross sections have been measured with use of an attenuation method for Li/sup +/ ions in the energy range from 1 to 10 keV incident on thin targets of Mg, Ca, Sr, and Ba vapors. These cross sections exhibit an energy dependence characteristic of asymmetric charge exchange, increasing with collision energy up to a broad maximum, then decreasing at higher energies. The Li/sup +/+Ba cross section reaches a maximum value (sigma/sub m/) of 4.0 x 10/sup -14/ cm/sup 2/ at approx. 3.5 keV impact energy. The corresponding values of sigma/sub m/ for Sr and Ca are 2.85 x 10/sup -14/ cm/sup 2/ at 6.0 keV, and 3.3 x 10/sup -15/ cm/sup 2/ at 10 keV. The Li/sup +/+Mg cross section only attains a value of 1.1 x 10/sup -15/ cm/sup 2/ at the highest energy measured (10 keV), thus, sigma/sub m/ clearly occurs at even higher energies for this system. The energies at which these cross-section maxima occur increase monotonically through the series from Mg to Ba, while the magnitude of sigma/sub m/ decreases in that order. This ordering is consistent with the inverse ordering of the asymptotic energy defects for the process: Li/sup +/(1s/sup 2/)+M(ns/sup 2/)..-->..Li(2s) +M/sup +/(ns), where M is an alkaline-earth element.

• Research Organization: Chemical Physics Laboratory, SRI International, Menlo Park, California 94025
• OSTI ID: 5481355
• Journal Information: Phys. Rev. A; (United States), Journal Name: Phys. Rev. A; (United States) Vol. 32:2; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ALKALI METALS
ALKALINE EARTH METALS
ATOM COLLISIONS
CAPTURE
COLLISIONS
CROSS SECTIONS
DATA
ELECTRON CAPTURE
ELEMENTS
ENERGY DEPENDENCE
ENERGY RANGE
EXPERIMENTAL DATA
INFORMATION
ION COLLISIONS
ION-ATOM COLLISIONS
KEV RANGE
KEV RANGE 01-10
LITHIUM
METALS
NUMERICAL DATA