Saddle point electrons in slow ion-atom collisions

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:199516

Pieksma, M; Eck, J van; Westerveld, W B ^[1]

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1. Utrecht Univ. (Netherlands); and others

The authors have investigated velocity distributions of electrons ejected in adiabatic atomic collisions, both experimentally and theoretically, in search for saddle point electrons. These electrons reside on/near the top of the internuclear potential barrier on the outgoing way of the collision. The so-called theory of hidden crossings, which describes this unusual and seemingly unstable ionization mechanism, will be discussed in some detail. The authors will also discuss the experimental set-up, in particular their newly designed {open_quotes}magnetic time-of-flight electron spectrometer.{close_quotes} For the H{sup +}-H system, at collision energies of 4 and 6 keV, the good agreement between theory and experiment, for both electron velocity distributions and integrated cross sections, strongly suggests the actual existence of a saddle point ionization mechanism. Besides the H{sup +}-H system the authors have also studied the He{sup 2+}-H (theory) and H{sup +}-He (experimental) collision systems.

• OSTI ID: 199516
• Report Number(s): CONF-941129--
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ADIABATIC PROCESSES
DISTRIBUTION FUNCTIONS
ELECTRONS
HELIUM
HELIUM IONS
HYDROGEN
HYDROGEN IONS 1 PLUS
ION-ATOM COLLISIONS
IONIZATION
KEV RANGE 01-10
VELOCITY