(e,2e) and (e,3-1e) studies on double processes of He at large momentum transfer

Journal Article · Thu Sep 15 04:00:00 EDT 2005 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.72.032705· OSTI ID:20718543

Watanabe, N; Takahashi, M ^[1]; Khajuria, Y ^[1]; Udagawa, Y ^[2]; Vinitsky, P S; Popov, Yu V ^[3]; Chuluunbaatar, O ^[4]; Kouzakov, K A ^[5]

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1. Institute for Molecular Science, Okazaki 444-8585 (Japan)
2. Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan)
3. Nuclear Physics Institute, Moscow State University, Moscow 119992 (Russian Federation)
4. Joint Institute for Nuclear Research, Dubna 141980, Moscow Region (Russian Federation)
5. Physics Department, Moscow State University, Moscow 119992 (Russian Federation)

The double processes of He in electron-impact ionization, single ionization with simultaneous excitation and double ionization, have been studied at large momentum transfer using an energy- and momentum-dispersive binary (e,2e) spectrometer. The experiment has been performed at an impact energy of 2080 eV in the symmetric noncoplanar geometry. In this way we have achieved a large momentum transfer of 9 a.u., a value that has never been realized so far for the study on double ionization. The measured (e,2e) and (e,3-1e) cross sections for transitions to the n=2 excited state of He{sup +} and to doubly ionized He{sup 2+} are presented as normalized intensities relative to that to the n=1 ground state of He{sup +}. The results are compared with first-order plane-wave impulse approximation (PWIA) calculations using various He ground-state wave functions. It is shown that shapes of the momentum-dependent (e,2e) and (e,3-1e) cross sections are well reproduced by the PWIA calculations only when highly correlated wave functions are employed. However, noticeable discrepancies between experiment and theory remain in magnitude for both the double processes, suggesting the importance of higher-order effects under the experimental conditions examined as well as of acquiring more complete knowledge of electron correlation in the target.

• OSTI ID: 20718543
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 3 Vol. 72; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ATOMS
ELECTRON CORRELATION
ELECTRON-ATOM COLLISIONS
ELECTRONS
EV RANGE
EXCITATION
EXCITED STATES
GEOMETRY
GROUND STATES
HELIUM
HELIUM IONS
IMPULSE APPROXIMATION
IONIZATION
MOMENTUM TRANSFER
WAVE FUNCTIONS