Coulomb focusing and path'' interference of autoionizing electrons produced in 10 keV He sup + + He collisions

Conference · Wed Mar 13 00:00:00 EST 1991

OSTI ID:5715524

Swenson, J K ^[1]; Burgdoerfer, J ^[2]; Meyer, F W; Havener, C C; Gregory, D C; Stolterfoht, N ^[3]

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1. Lawrence Livermore National Lab., CA (USA)
2. Tennessee Univ., Knoxville, TN (USA)
3. Oak Ridge National Lab., TN (USA)

Autoionizing electrons emitted following low energy ion-atom collisions may scatter significantly from the receding spectator ion's attractive Coulomb field. In such cases the observed electron intensity is focused'' in the direction of the scattering ion as a result of the effective compression of the emission solid angle. In addition, interference may occur between trajectories, corresponding to electrons scattering around opposite sides of the ion, which lead to the same final laboratory electron energy and emission angle. This Coulomb path'' interference mechanism manifests itself in the uncharacteristically rapid angular dependence of the He target 2s{sup 2} {sup 1}S autoionizing state measured near 0{degree} following low energy He{sup +} + He collisions. A classical trajectory model for Coulomb focusing is presented and a semi-classical approximation is used to model the Coulomb path'' interference mechanism. In this description we account for the evolution of the phase of the autoionizing state until its decay and the path dependence of the amplitude of the emitted electron following decay of the autoionizing state. Calculated model lineshapes, which include contributions from adjacent overlapping resonances, reproduce quite well the angular dependence observed in the data near 0{degree}. 14 refs., 7 figs.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5715524
• Report Number(s): UCRL-JC-107202; CONF-9103146-4; ON: DE91013249
• Resource Relation: Conference: 3. US/Mexico atomic and molecular physics workshop, Mexico City (Mexico), 13-16 Mar 1991
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
HELIUM
AUTOIONIZATION
ION-ATOM COLLISIONS
COULOMB FIELD
ELECTRON SPECTRA
ENERGY DEPENDENCE
HELIUM IONS
LINE WIDTHS
ATOM COLLISIONS
CHARGED PARTICLES
COLLISIONS
ELECTRIC FIELDS
ELEMENTS
FLUIDS
GASES
ION COLLISIONS
IONIZATION
IONS
NONMETALS
RARE GASES
SPECTRA
640304* - Atomic
Molecular & Chemical Physics- Collision Phenomena
640302 - Atomic
Molecular & Chemical Physics- Atomic & Molecular Properties & Theory