Accession Number : ADA111828

Title :   Development of COCHISE UV Absorption System.

Descriptive Note : Final rept. 7 Jul 80-30 Oct 81,

Corporate Author : PHYSICAL SCIENCES INC WOBURN MA

Personal Author(s) : Piper,L G ; Murphy,H C ; Rawlins,W T

PDF Url : ADA111828

Report Date : Dec 1981

Pagination or Media Count : 66

Abstract : Under this program PSI developed a resonance lamp to be used to measure number densities of N(2D) and N(2P) in the COCHISE facility using the technique of vacuum ultraviolet resonance absorption. The lamps consist of sapphire tubes through which argon containing a trace of molecular nitrogen flows. A low power microwave discharge through the gas excites the VUV resonance lines which are diagnostic of the atomic nitrogen metastables (149.3 nm for N(2D) and 174.3 nm N(2P). An interference filter is used to isolate the appropriate resonance multiplet, and the radiation, after traversing the COCHISE reaction zone twice, is detected with a solar-blind photomultiplier. The major lamp-design criterion is dictated by the important excitation mechanisms in the lamp. VUV resonance-line excitation mechanisms are discussed in detail, and experimental methods for elucidating these mechanisms are presented. (Author)

Descriptors :   *ULTRAVIOLET RADIATION, *RESONANCE ABSORPTION, *FILTERS, *INTERFERENCE, ARGON, REACTION KINETICS, VACUUM, EXCITATION, FLOW, MOLECULAR PROPERTIES, NITROGEN, SAPPHIRE, EXPERIMENTAL DATA, PHOTOMULTIPLIER TUBES, ATOMS, METASTABLE STATE, PLASMAS(PHYSICS)

Subject Categories : Ultraviolet Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE