State selective extreme ultraviolet (EUV) photoemission cross sections for excitation and ionization-excitation of helium in fast electron and positive ion collisions: He{sup {lg_bullet}} (1snp) {sup 1}P{sup {lg_bullet}} (n=2 to 10) and He{sup +} (np) (n=2 to 10) Rydberg states
- Univ. of Nevada, Reno, NV (United States); and others
We have analyzed high resolution (EUV) spectra of HeI and HeII originating from e{sup -}, H{sup +}, H{sub 2}{sup +} and H{sub 3}{sup +} bombardment of He gas. From these data excitation and ionization-excitation cross sections have been obtained by the HeI (1snp){sup 1}P{sup o} {yields} (1s2){sup 1}S + h{nu} and HeII (np){sup 2}P{sup o}-(1s){sup 2}S + h{nu} Rydberg series with main quantum numbers from n=2 to 10, respectively. The determination of the individual line intensities has been accomplished using the IRAF one dimensional spectroscopy package installed on the Physics Department`s HP9000 system. The cross sections for n{>=}4 presented here are reported for the first time. The up manifolds have been studied as a function of the projectile charge and velocity and number of scattering centers. Theoretically we have parametrized the cross sections in terms of first order, second order and interference contributions. We have also tested sum rules, by integrating over all np states. The dynamical Stark mixing among HeII ns and np states has also been investigated. A detailed discussion of the intensity distribution at high np states is presented for different means of excitation.
- OSTI ID:
- 281418
- Report Number(s):
- CONF-9305421-; ISSN 0003-0503; TRN: 96:019343
- Journal Information:
- Bulletin of the American Physical Society, Vol. 38, Issue 3; Conference: 1993 American Physical Society annual meeting on atomic, molecular, and topical physics, Reno, NV (United States), 16-19 May 1993; Other Information: PBD: May 1993
- Country of Publication:
- United States
- Language:
- English
Similar Records
Observation of charge-transfer population of high-n levels in Ar/sup +16/ from neutral hydrogen in the ground and excited states in a tokamak plasma
Characteristics of a multilayer mirror polarimeter for measurements at extreme ultraviolet wavelengths