ISSN:
1432-0649
Keywords:
42.55 Dk
;
33.80 eH
;
52.80-s
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract In sealed CO2 spark preionised lasers the preionisation is largely due to photoionisation of NO and NO2, in seeded TEA lasers it originates from the low ionisation potential additive used. Unseeded and flowing gas lasers can still be successfully preionised but the source of this preionisation has remained a mystery; previous attempts to isolate and identify low I.P. gaseous impurities have failed. We have now identified these, using a combination of cryogenic impurity concentration and mass spectroscopy and found them to be a complex mixture of hydrocarbons (C2−C7). Of these hydrocarbons, the alkenes are found to be predominantly responsible for the photoionisation and are present in concentrations of ∼ 0.5 ppm. Deliberate addition of one of these alkenes, propene, to a uv preionised CO2 TEA laser was found to enhance the lasers performance at high energy loadings.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00690018
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