Field-induced dissociation of O{sub 2}{sup *} in a fast beam

Journal Article · Sat May 01 04:00:00 EDT 1993 · Bulletin of the American Physical Society

OSTI ID:281200

Hazell, I; Cosby, P C; Walter, C W; Helm, H

A keV energy beam of O{sub 2} produced by charge transfer of O{sub 2}{sup +} (a{sup 4}{Pi}{sub u}) in Cs vapor is found to be rapidly ({tau}{le} 35 ns) predissociated during passage through a 300 {mu}m wide slit. Spatial and temporal analysis of the correlated dissociation fragments locate the dissociating O{sub 2}{sup *} levels at an energy {approximately} 0.02 eV below the vibrational levels of O{sub 2}{sup +} X{sup 2}{Pi}{sub g} and reveal predissociation of at least 7 discrete vibrational levels to the O({sup 1}S)+O({sup 1}D), O({sup 1}D)+O({sup 1}D), O({sup 1}D)+O({sup 3}P), and O({sup 3}P)+O({sup 3}P) separated atom limits. Studies of the fragmentation as a function of electric field strength applied across the slit suggest that the observed dissociation arises form a mixing of high nl (n>30) Rydberg states built on an X{sup 2}{Pi}{sub g} core that is induced by very weak fields. Predissociation of v > 0 is suppressed by field ionization of these vibrational levels at a rate increasing with applied field. The observed branching among the dissociation channels appears to be relevant to that which would be produced in the dissociative recombination of O{sub 2}{sup +}(X{sup 2}{Pi}{sub g},v).

• OSTI ID: 281200
• Report Number(s): CONF-9305421--; CNN: Contract F 33615-90-C-007
• Journal Information: Bulletin of the American Physical Society, Journal Name: Bulletin of the American Physical Society Journal Issue: 3 Vol. 38; ISSN BAPSA6; ISSN 0003-0503
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
DISSOCIATION
OXYGEN
PHOTOIONIZATION
PHOTON-MOLECULE COLLISIONS
VIBRATIONAL STATES