ISSN:
1089-7623
Source:
AIP Digital Archive
Topics:
Physics
,
Electrical Engineering, Measurement and Control Technology
Notes:
This paper deals with the specifications and the possibilities of a novel highly sensitive optical absorption spectroscopy method. It consists of a cascaded arc as an extremely bright broadband light source with a high resolution spectrometer as a detector. Its interest for a continuous quantitative monitoring of the densities of waste atoms and molecules in the atmosphere is investigated. To this end, theoretical considerations are given with respect to the detection limits and the resolution necessary for selective spectrochemical analysis. In the first measurements with the setup, on a laboratory argon-hydrogen plasma, the versatility and sensitivity of the technique for measuring low species densities is demonstrated. Densities of the sublevels of the argon first excited state, the four Ar(3p54s) metastable and resonant substates, were measured simultaneously in one measuring sequence. The data were analyzed using an efficient line of sight integration technique. The densities of these substates are of the order of 1017 m−3 in a plasma with a pressure of 40 Pa. For the atomic hydrogen H(n=2) state, densities of the order of 1014 m−3 over a length of about 2 cm could be measured, representing a detection limit of approximately 2×1012 m−2. © 1995 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1145631
