Segmented Ge detectors and mechanical coolers for future gamma-ray astronomy instrumentsThe effectiveness of a segmented Ge detector in rejecting background events due to the beta decay of internal radioactivity is demonstrated by a laboratory experiment in which radioactivity was produced in the detector by neutron irradiation. A Cf-252 source of neutrons was used to produce, by neutron capture on Ge-74 in the detector itself, Ge-75, which decays by beta emission with a maximum energy of 1188 keV. Simultaneous spectra are taken of the activity in the detector under two conditions: a free spectrum in which all events in the detector are accumulated, and a gated spectrum in which events are accumulated only if they deposit energy in two or more segments. A comparison of the spectra shows that over 85 percent of the beta events are rejected, which is in good agreement with predictions.
Document ID
19910063388
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Varnell, Larry S. (JPL Pasadena, CA, United States)
Date Acquired
August 14, 2013
Publication Date
January 1, 1990
Subject Category
Spacecraft Instrumentation
Meeting Information
Meeting: High-energy astrophysics in the 21st century