Accession Number : ADP004447

Title :   The Flowing Afterglow in Argon and Helium: Differences in Two Reactor Designs in Application to the Analysis of Moisture,

Corporate Author : LAWRENCE LIVERMORE NATIONAL LAB CA

Personal Author(s) : Bystroff,R. I. ; Stout,N. D.

Report Date : 02 JUN 1982

Pagination or Media Count : 10

Abstract : Excitation by rare gas metastables in a glow discharge afterglow is effective for the sensitive chemiluminescent detection of trace moisture. In the development of a flowing afterglow (FLAG) system for the study of effluent gases from high explosives, two approaches were taken in the design of a modular reactor. A glass reactor system with a tantalum shell hollow cathode source isolated by a Woods horn was compared to a 3 in. dia. steel reactor in which the reactor entrance port acts as the cathode. The sensitivity of both systems increases linearly with currents up to 15 microaluminum in operation at 1 Torr argon or helium. The steel reactor provides an order of magnitude greater sensitivity for OH than the glass reactor. A continuous moisture background at 60 C over vacuum dried nitrocellulose of 0.9 nmol/gm-s (0.02 ppm) is demonstrated. With the steel system a photon count sensitivity for OH at 308.9 nm of 30000 counts/nmol in argon and 5200 counts/nmol in helium is obtained using a 0.4 nm badnpass.

Descriptors :   *EXPLOSIVE GASES, *MOISTURE CONTENT, *CHEMILUMINESCENCE, *TEST REACTORS, GLASS, STEEL, EXCITATION, HELIUM, ARGON, METASTABLE STATE, MOISTURE, EFFLUENTS, GLOW DISCHARGES, AFTERGLOWS, CATHODES, SENSITIVITY, NITROCELLULOSE, HIGH EXPLOSIVES, SYMPOSIA

Distribution Statement : APPROVED FOR PUBLIC RELEASE