Backup for the gamma-ray detector installed in the "wheel" section on the OSO-1 satellite launched on 7 March 1962. The detector, built at the University of Rochester, includes two scintillators and a Cerenkov counter. Entering gamma-rays impinge on a thin lead sheet in the instrument; the collision converts the high energy photon to an electron-positron pair. Those charged particles then lead to a flash of light in the Lucite Cerenkov counter. The resulting flashes are amplified and counted by a photomultiplier tube. The scintillators form part of the anti-coincidence circuit that accepts only those signals that enter the detector from the front. The instrument on OSO-1 detected the cosmic ray background but did not provide clear evidence for high energy solar events. The detector was transferred to NASM from the Smithsonian Astrophysical Observatory in December 1982.
Transferred from the Smithsonian Astrophysical Observatory