Patent ID: 9091772
Filing Date: 2015-07-28
Classification: G01J,G01T,H04N

Abstract:
1. A method for controlling gain in a scintillation detector comprising a scintillator and a photomultiplier tube which receives light from the scintillator, the method comprising: exposing the scintillator to a radiation source; obtaining calibration count rates from the photomultiplier tube, each representing an integral count rate above a different energy threshold; performing a first comparison of at least some of the calibration count rates, and when a result of the first comparison indicates that the calibration count rates do not correspond with a reference peak in the energy spectrum of the radiation source, performing a first adjustment of the photomultiplier tube gain until the result indicates the calibration count rates correspond with the reference peak; and performing a second comparison of at least some of the calibration count rates which is different from the first comparison and, when a result of the second comparison varies from a relationship of integral count rate versus the different energy thresholds resulting from the reference peak, performing a second adjustment of photomultiplier tube gain so as to reduce the variation.