Electron-electron interaction in ion-atom collisions studied by projectile state-resolved Auger-electron spectroscopy

Thesis/Dissertation · Mon Jan 01 04:00:00 EST 1990

OSTI ID:5524660

Dohyung, Lee

This dissertation addresses the problem of dynamic electron-electron interactions in fast ion-atom collisions using projectile Auger electron spectroscopy. The study was carried out by measuring high-resolution projectile KKL Auger electron spectra as a function of projectile energy for the various collision systems of 0.25-2 MeV/u O{sup q+} and F{sup q+} incident on H{sub 2} and He targets. The electrons were detected in the beam direction, where the kinematic broadening is minimized. A zero-degree tandem electron spectrometer system, was developed and showed the versatility of zero-degree measurements of collisionally-produced atomic states. The zero-degree binary encounter electrons (BEe), quasifree target electrons ionized by the projectiles in head-on collisions, were observed as a strong background in the KLL Auger electron spectrum. They were studied by treating the target ionization as 180{degree} Rutherford elastic scattering in the projectile frame, and resulted in a validity test of the impulse approximation (IA) and a way to determine the spectrometer efficiency. An anomalous q-dependence, in which the zero-degree BEe yields increase with decreasing projectile charge state (q), was observed. State-resolved KLL Auger cross sections were determined by using the BEe normalization and thus the cross section of the electron-electron interactions such as resonant transfer-excitation (RTE), electron-electron excitation (eeE), and electron-electron ionization (eeI) were determined. Projectile 2l capture with 1s {yields} 2p excitation by the captured target electron was observed as an RTE process with Li-like and He-like projectiles and the measured RTEA (RTE followed by Auger decay) cross sections showed good agreement with an RTE-IA treatment and RTE alignment theory.

• Research Organization: Kansas State Univ., Manhattan, KS (United States)
• OSTI ID: 5524660
• Country of Publication: United States
• Language: English

Related Subjects

664300* -- Atomic & Molecular Physics-- Collision Phenomena-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
ATOM COLLISIONS
AUGER EFFECT
AUGER ELECTRON SPECTROSCOPY
CATIONS
CHARGED PARTICLES
COLLISIONS
CROSS SECTIONS
ELECTRON SPECTROSCOPY
ELECTRON-ELECTRON INTERACTIONS
ELEMENTS
ENERGY-LEVEL TRANSITIONS
EXCITATION
FLUIDS
GASES
HELIUM
HYDROGEN
INTERACTIONS
ION COLLISIONS
ION-ATOM COLLISIONS
ION-MOLECULE COLLISIONS
IONIZATION
IONS
IRON IONS
LEPTON-LEPTON INTERACTIONS
MOLECULE COLLISIONS
MULTICHARGED IONS
NONMETALS
OXYGEN IONS
PARTICLE INTERACTIONS
RARE GASES
RECOMBINATION
SPECTROSCOPY