Electron capture into excited states of helium by helium-ion impact on helium
Cross sections for electron capture into each excited state of He up to 4 $sup 1$$,$$sup 3$D by He$sup +$ impact on He in the energy range 100--10 000 keV have been calculated by means of the first Born approximation (Bates's version). A Gaussian technique previously developed for evaluating two-center integrals occurring in the Born amplitude has been used. One-parameter, variational wave functions are derived for each excited state of helium up to 4 $sup 1$$,$$sup 3$D. Some of the excited $sup 1$S cross sections are found to be affected by almost a factor of 2 by the choice of 1 $sup 1$S helium wave function and orthogonality of the excited state $sup 1$S functions to this function. The observed departure of the ratio of triplet to singlet cross sections from the statistical weight of three is related partly to the interference between a one-electron process of capture into an excited state of helium and a two-electron process of capture into the ground state with the original He$sup +$ electron excited, and is related partly to the difference between the variational singlet and triplet excited one-electron wave functions. At energies of about 100 keV, agreement with available experimental results is generally good; however, for the 3 $sup 1$P, 4 $sup 1$P, and 4 $sup 1$D states, the disagreement exceeds the estimated experimental uncertainty.
- Research Organization:
- Department of Physics, Rice University, Houston, Texas 77001
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-33-001851
- OSTI ID:
- 4169643
- Journal Information:
- Phys. Rev., A, v. 12, no. 2, pp. 434-443, Journal Name: Phys. Rev., A, v. 12, no. 2, pp. 434-443; ISSN PLRAA
- Country of Publication:
- United States
- Language:
- English
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*HELIUM IONS-- ION-ATOM COLLISIONS
*HELIUM-- ION-ATOM COLLISIONS
640304* --Physics Research--Atomic
Molecular & Chemical Physics--Collision Phenomena
BORN APPROXIMATION
ENERGY RANGE
KEV RANGE 100-1000
MEV RANGE 01-10
N60400* --Physics (Atomic & Molecular)--Collision Phenomena