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Title: Absolute total and one- and two-electron transfer cross sections for Ar[sup [ital q]+] (8[le][ital q][le]16) on He and H[sub 2] at 2. 3[ital q] keV

Journal Article · · Physical Review A; (United States)
; ; ;  [1]
  1. Nuclear Science and Engineering Program, Ward Laboratory, Cornell University, Ithaca, New York 14853 (United States)

Absolute values for the total and one- and two-electron transfer cross sections for Ar[sup [ital q]+] ions (8[le][ital q][le]16) colliding with helium and molecular hydrogen at 2.3[ital q] keV laboratory energy were measured by the growth-rate method. The He and H[sub 2] total cross sections as a function of Ar-projectile [ital L]-shell occupation number increase monotonically from Ar[sup 8+], 2[ital p] shell full, to Ar[sup 16+], 2[ital s] shell empty. The H[sub 2] one-electron capture cross section scales approximately as [[ital E][sub IP] (He)/[ital E][sub IP](H[sub 2])][sup 2] times the corresponding He cross section, but the shapes of the two cross sections differ in detail. The Ar[sup [ital q]+] ions were produced by the Cornell superconducting-solenoid, cryogenic electron-beam ion source (CEBIS) and extracted at 2.3 kV. Selected charge states traversed a gas cell, after which they were detected and charge-state analyzed by the energy-retardation method and by a [pi]/ [radical]2 cylindrical electrostatic analyzer. The target-gas pressure in the cell was measured directly by the orifice-flow method used for absolute-pressure gauge calibration. The overall error in the Ar[sup [ital q]+] on H[sub 2] cross-section measurements is [plus minus]10%, and [plus minus]15% in the He measurements.

DOE Contract Number:
FG02-86ER13519
OSTI ID:
6609705
Journal Information:
Physical Review A; (United States), Vol. 47:5; ISSN 1050-2947
Country of Publication:
United States
Language:
English