Double differential electron emission cross sections for double excitation and single ionization of helium by fast e{sup {minus}}, H{sup +}, He{sup +} and He{sup 2+} projectiles at zero degree observation in the vicinity of the (2p{sup 2}){sup 1}D and (2s2p) {sup t}P{sup O} resonances
- Univ. of Nevada, Reno, NV (United States); and others
Double differential cross sections of doubly excited autoionizing (2p{sup 2}){sup 1}D and (2s2p){sup 1}P states due to 150 eV-1 keV electron, 100 keV-1.5 MeV H{sup +}, 400 KeV-1.6 MeV He{sup +} and He{sup ++} impact on He were measured at zero degree observation angle. Two electrostatic spectrometers were used in tandem where the first analyzer separates the emitted electrons from the incident projectile beam and the second analyzer provides high resolution performance. The projectile beam was tightly collimated and then traversed a 9 mm long gas cell containing 20 mT He gas. All measurements have been performed under single collision conditions. Strong interference effects between resonance lines and direct ionization continuum are evident in the observed spectra in particular for slower positive projectile ions due to strong Coulomb Interaction in the Final States (CIFS). Our double differential cross sections have been absolutely calibrated using the theoretical and semiempirical single ionization data given by Kim and Rudd. The experimental results are compared with theoretical calculations including three CFIS.
- OSTI ID:
- 281415
- Report Number(s):
- CONF-9305421--
- Journal Information:
- Bulletin of the American Physical Society, Journal Name: Bulletin of the American Physical Society Journal Issue: 3 Vol. 38; ISSN BAPSA6; ISSN 0003-0503
- Country of Publication:
- United States
- Language:
- English
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