NSSDCA ID: 1969-006A-06
Mission Name: OSO 5This flight instrument was designed for studying the line shape of the solar Lyman-alpha line summed over the entire solar disk. It made use of the optical resonance of hydrogen and deuterium gases. A grating and mirror system converted the incident solar radiation into a beam of Lyman-alpha light (1216 A) with a bandwidth of 100 A, which entered two resonance cells. One cell was filled with molecular hydrogen and the other cell was filled with molecular dueterium gas. Each cell had a photomultiplier mounted at its exit window to measure the total intensity of the solar spectrum in the 100-A bandwidth. In addition, each cell had a photomultiplier mounted at right angles to the cell (i.e., at right angles to the incident beam) that measured the intensity of the light scattered by the cell. Heated filaments in these cells dissociated some of the gas, and different concentrations of atomic species in the cells were obtained by varying filament voltage. The signal on the right angle detectors was proportional to the intensity of the incident light at 1215.664 A for the hydrogen cell (0.015 A bandwidth) and at 1215.335 A for the deuterium cell (0.011 A). Scanning was accomplished by a doppler shift due to approaching and receding velocity of the spacecraft with relation to the sun at orbit morning and evening. An internal calibration lamp was included in the experiment. The experiment operated 1 h every 2 calendar days. More experiment details and some measured data are contained in the paper, 'Solar Lyman alpha changes and related hydrogen density distribution at the earth's exobase (1969-1970),' A. Vidal-Madjar, et al, J. Geophys. Res., 78, 7, 1115-1144, March 1973.
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Name | Role | Original Affiliation | |
---|---|---|---|
Mr. Pierre Coufleau | Other Investigator | Observatoire de Paris, Meudon | |
Prof. Jacques E. Blamont | Principal Investigator | CNRS, Service d'Aeronomie |