A MODEL OF THE GAMMA-RAY BACKGROUND ON THE BATSE EXPERIMENT

The BATSE experiment on the Compton Gamma-Ray Observatory is a nearly uninterrupted all-sky monitor in the hard X-ray/gamma-ray energy range . Count rate data continuously transmitted to the ground from Low Eart h Orbit (altitude similar to 450 km) is dominated, in the 20-300 keV e nergy range, by diffuse cosmic background modulated by blocking effect s of the Earth. Other background sources include atmospheric gamma-ray s and the decay of radionuclides created in cosmic ray and radiation b elt trapped particle interactions with the detector. Numerous discrete cosmic sources are also present in these data. In this paper we descr ibe a semi-empirical background model which has been used to reduce th e effect of dominant background sources. The use of this model can inc rease the sensitivity of the experiment to sources observed with the E arth occultation technique; to long period pulsed sources; to analysis of flickering noise; and to transient events.