The High Energy X-Ray Timing Experiment (HEXTE), currently under development for the X-Ray Timing Explorer (XTE) mission, employs a closed loop gain control system to attain 0.5 percent stabilization of each of eight-phoswich detector gains. This Automatic Gain Control (AGC) system utilizes a split window discriminator scheme to control the response of each detector pulse height analyzer to gated Am-241 X-ray events at 60 keV. A prototype AGC system has been implemented and tested within the gain perturbation environment expected to be experienced by the HEXTE instrument in flight. The AGC system and test configuration are described. Response, stability and noise characteristics are measured and compared with theoretical predictions. The system is found to be generally suitable for the HEXTE application.

Date Published: 1 October 1991
PDF: 13 pages
Proc. SPIE 1549, EUV, X-Ray, and Gamma-Ray Instrumentation for Astronomy II, (1 October 1991); doi: 10.1117/12.48334

Published in SPIE Proceedings Vol. 1549:
EUV, X-Ray, and Gamma-Ray Instrumentation for Astronomy II
Oswald H. W. Siegmund; Richard E. Rothschild, Editor(s)