Radiant emittance of xenon positive column discharges
- General Electric Co., Schenectady, NY (United States). Corporate Research and Development
An embodiment of a mercury-free fluorescent lamp combines a low pressure rare gas discharges with a phosphor having a quantum efficiency grater than one. The choice of the rare gas depends on a number of factors, one of which is the resonance transition energy. Less demand is placed the quantum efficiency of the phosphor for a lower energy resonance photon. Xenon has the lowest energy resonance transition of the stable rare gases at 8.5 eV (147 nm) and thus is a good candidate to study. The usefulness of a xenon-based discharge depends on the radiant emittance of the discharge at the resonance wavelength of 147 nm. The radiant emittance from a low pressure xenon positive column discharge is measured using two independent techniques. The first relies on the measurement of the resonance level density using absorption techniques. The effective decay rate of the resonance level is calculated using radiation trapping theory. The product of this density and trapped decay rate yields the radiant emittance. The second technique measures the 147 nm radiance normal to the positive column axis using a NIST-calibrated cesium-telluride photodiode. These plasmas tend not to be diffuse radiators so that the angular distribution of the 147 nm radiation cannot be assumed to be cosine. The angular distribution of the resonance radiation is determined from a Monte Carlo simulation of the transport of resonance radiation in a cylindrical geometry. The photodiode measurement places the angular distribution of the radiance on an absolute scale, which can then be integrated to yield the radiant emittance.
- OSTI ID:
- 63077
- Report Number(s):
- CONF-940604-; ISBN 0-7803-2006-9; TRN: IM9527%%128
- Resource Relation:
- Conference: 1994 Institute of Electrical and Electronic Engineers (IEEE) international conference on plasma science, Santa Fe, NM (United States), 6-8 Jun 1994; Other Information: PBD: 1994; Related Information: Is Part Of 1994 IEEE international conference on plasma science; PB: 252 p.
- Country of Publication:
- United States
- Language:
- English
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