Scintillation Detector Gain Control

摘要

From a determination of a plot of total count rate v discrimination level, upper, lower and intermediate values of voltage threshold are determined representing a linear slope on the plot that represents the reference peak. In use with a calibration radiation source, a first comparison is made to determine whether the ratio of counts at upper and lower thresholds represent the correct reference peak. A second comparison is then made between the differences of count rates for intermediate and lower compared with upper and intermediate rates to determine whether the measured reference peak has shifted. If the differences are not approximately equal the gain is adjusted accordingly.