Excitation of mercuric bromide by electrons. Final report 15 May 81-30 Jun 82

Technical Report · Mon Aug 30 04:00:00 EDT 1982

OSTI ID:6460717

Chantry, P J; Chen, C L

Computer modelling of the HgBr discharge laser requires as input the various cross sections for electron impact on HgBr/sub 2/. One of the most important of these is the cross section for production of the HgBr* (B doublet sigma one-half), the upper laser state, by electron impact on HgBr/sub 2/. This report describes work performed to measure the total emission cross section for production of the HgBr B-X fluorescence. Under the conditions of the experiment this corresponds to the total formation cross section for the HgBr*(B) state. A magnetically collimated electron beam (1-200 eV) crosses a low density molecular beam of HgBr/sub 2/. The apparatus permits simultaneous measurements of negative ion, positive ion, and wavelength resolved photon production from HgBr/sub 2/, and from permanent bottled gases. The relative wavelength dependence of the photon counting system has been determined from 280 to 640 nm using standard lamps. By comparison with known ionization and total emission cross sections in He, it is possible to measure total emission cross sections for other molecules whose ionization cross sections are known. The HgBr*(B) emission extends from 510 nm to beyond 350 nm, and appropriate integration over wavelength is necessary. The resulting cross section has a sharp onset at 6.0 eV and rises rapidly to a plateau with a mean value of 3.2 (-16) sq cm. In the region (3-5 eV) of dissociative attachment HgBr*(B) production is undetectable, corresponding to sigma < (-18) sq cm.

• Research Organization: Westinghouse Electric Corp., Pittsburgh, PA (USA). Research and Development Center
• OSTI ID: 6460717
• Report Number(s): AD-A-119583/3
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420300* -- Engineering-- Lasers-- (-1989)
BEAMS
BROMIDES
BROMINE COMPOUNDS
CROSS SECTIONS
ELECTRODES
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ELECTRONS
ELEMENTARY PARTICLES
ELEMENTS
EMISSION
ENERGY-LEVEL TRANSITIONS
EXCITATION
FERMIONS
FLUIDS
FLUORESCENCE
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HELIUM
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LEPTONS
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MERCURY COMPOUNDS
MOLECULAR BEAMS
NONMETALS
PARTICLE BEAMS
PHOTONS
RARE GASES