Detection of Artificial Sources of Nuclear Radiation in Space. Revision

The gamma-ray experiment on board NASA's Solar Maximum Mission Satellite (SMM) has detected nuclear radiation emitted from the reactor on COSMOS 1176. Direct observations of gamma-rays and possibly neutrons from this reactor have been made at distances as close as about 350 km. Nuclear line features have been observed in the gamma-ray spectrum. Explanations for some of these features are presented. The absolute power of the reactor is difficult to estimate at present; however, there is evidence that both the intensity and spectral shape of the emitted radiation changed significantly during the operational period of COSMOS. The reactor was also detected at distances of or = 6,300 km in an indirect manner. Positrons and electrons escaping from the COSMOS spacecraft following production by the intense gamma-radiation are stored temporarily in the Earth's magnetic field and unambiguous signal due to their characteristic annihilation into gamm-rays at 511 keV. Details of these observations and their implications are discussed. Prepared in colloboration with Univ. of New Hampshire, Durham. Dept. of Physics and Los Alamos Scientific Lab., NM. Revision of Rept. no. NRL-MR-4596, AD-C025 833L.