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Tropospheric ho determination by fage
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Chan, C. Y. Mehrabzadeh, A. A. Obrien, R. J. Hard, T. M. |
| Copyright Year | 1986 |
| Description | In the detection of tropospheric HO by laser excited fluorescence, and alternative air-sampling method, named FAGE (Fluorescence Assay with Gas Expansion) was introduced. Here the air is expanded through a nozzle prior to excitation, in order to improve the ratio of the HO signal to the scattered, fluorescent, and photolytic backgrounds. The improvement comes from the differing pressure dependence of the intensities of these four terms, as well as the distinguishability of their temporal waveforms at low pressures when excited by a pulsed laser. HO has been excited by a YAG/dye laser. Other lasers and pumping paths may perform as well or better in this method. With FAGE, chemical modulation of the HO signal was achieved by hydrocarbon addition to the nozzle flow, converting photolytic HO from an interference to a background. Chemical calibration of the instrumental response to external HO was also achieved, by hydrocarbon decay, at HO concentrations within the ambient range. |
| File Size | 118583 |
| Page Count | 2 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19870006099 |
| Archival Resource Key | ark:/13960/t9091528k |
| Language | English |
| Publisher Date | 1986-12-01 |
| Access Restriction | Open |
| Subject Keyword | Geophysics Pressure Dependence Chemical Analysis Photolysis Laser Pumping Air Sampling Yag Lasers Troposphere Laser Induced Fluorescence Hydroxyl Radicals Dye Lasers Gas Expansion Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
