Double photodetachment from the Cl[-]ion
Journal article, 2004

The correlated process involving the photodetachment of two electrons from the [Formula Presented] ion has been investigated over the photon energy range 20–45 eV. In the experiment, a beam of photons from the Advanced Light Source (ALS) was collinearly merged with a counterpropagating beam of [Formula Presented] ions from a sputter ion source. The [Formula Presented] ions produced in the interaction region were detected, and the normalized signal was used to monitor the relative cross section for the reaction. An absolute scale for the cross section was established by measuring the spatial overlap of the two beams and by determining the efficiency for collection and detection of the [Formula Presented] ions. The overall magnitude and shape of the measured cross section for this process agrees well with an R-matrix calculation. The calculation identifies the dominant mechanism leading to the production of the [Formula Presented] ion as being a direct nonresonant process involving the ejection of a pair of electrons from the valence shell. Less important is the indirect nonresonant process that involves the production and decay of core-excited and doubly excited states of the Cl atom in an intermediate step. Direct and indirect resonant mechanisms involving the excitation of a single [Formula Presented] core electron or more than one valence electron of the [Formula Presented] ion were found to be insignificant in the energy range studied.


A. Aguilar

University of Nevada, Reno

J. S. Thompson

University of Nevada, Reno

D. Calabrese

Sierra College

A. M. Covington

Lake Tahoe Community College

C. Cisneros

Universidad Nacional Autonoma de Mexico

V. T. Davis

United States Military Academy at West Point

M. S. Gulley

Los Alamos National Laboratory

M. Halka

Embry-Riddle Aeronautical University

Dag Hanstorp

Chalmers, Department of Experimental Physics

University of Gothenburg

Joakim Sandström

Chalmers, Department of Experimental Physics

B. M. McLaughlin

Queen's University Belfast

D. J. Pegg

University of Tennessee

Physical Review A - Atomic, Molecular, and Optical Physics

1050-2947 (ISSN) 1094-1622 (eISSN)

Vol. 69 2 8-8

Subject Categories

Accelerator Physics and Instrumentation

Subatomic Physics

Atom and Molecular Physics and Optics



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