Role of excitation in K-shell vacancy production for F/sup 6 +/+He collisions

Journal Article · Sat Dec 01 04:00:00 EST 1979 · Phys. Rev., A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.20.2340· OSTI ID:5857237

Tawara, H; Terasawa, M; Richard, P; Gray, T J; Pepmiller, P; Hall, J; Newcomb, J

Cross sections have been measured for K-shell vacancy production for F/sup 6 +/(1s/sup 2/2s) ions incident on He target atoms in the projectile energy range from 10 to 40 MeV. Collisions leading to F/sup 6 +/(1s2s2p) states are attributed to K-shell excitation. The cross sections for F/sup 6 +/(1s/sup 2/2s) to F/sup 6 +/(1s2s2p) excitation agree with a Born calculation for 1s-electron excitation. Collisions leading to F/sup 7 +/(1s2p) states are referred to as K-vacancy production to distinguish it from the K-shell excitation process. The energy dependence of the K-vacancy production cross section for the F/sup 6 +/(1s/sup 2/2s) to F/sup 7 +/(1s2p) process does not agree with the calculation for single 1s-electron ionization. The observed energy dependence is understood in terms of the sum of two two-step processes. One two-step process is 1s-electron ionization simultaneous with 2s-2p--electron excitation and the other is 2s-electron ionization simultaneous with 1s-2p--electron excitation. The latter process is dominant. The F/sup q/+ charge-state dependence at 15 MeV and the F/sup 8 +/ energy dependence for electron excitation, as previously reported, are also compared with theory.

• Research Organization: Department of Physics, Kansas State University, Manhattan, Kansas 66506
• OSTI ID: 5857237
• Journal Information: Phys. Rev., A; (United States), Journal Name: Phys. Rev., A; (United States) Vol. 20:6; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ATOM COLLISIONS
CHARGED PARTICLES
COLLISIONS
CROSS SECTIONS
CRYOGENIC FLUIDS
ELECTRONIC STRUCTURE
ELEMENTS
ENERGY DEPENDENCE
ENERGY RANGE
ENERGY-LEVEL TRANSITIONS
EXCITATION
FLUIDS
FLUORINE IONS
HELIUM
ION COLLISIONS
ION-ATOM COLLISIONS
IONIZATION
IONS
K SHELL
MEV RANGE
MEV RANGE 10-100
MULTICHARGED IONS
NONMETALS
RARE GASES