Dead time compensation circuit for radiation detector

Abstract

A Geiger-Mueller tube-based radiation measurement device includes circuitry for the correction of the dead time losses associated with the Geiger-Mueller tube. As the event count rate rises, the transfer function (e.g., the closed loop voltage gain) of an operational amplifier responding to an event count rate signal is modified to compensate for dead time losses experienced at high count rates. Preferably, an analog switch controlled by the event count rate signal automatically sets the voltage gain of the operational amplifier at a level corresponding to the desired amount of dead time compensation required to provide an accurate measurement of actual events. The dead time correction circuitry disclosed herein finds practical application in the use of well-known analog rate meter circuits of the charge pump type.