Automatic dead-time correction for multichannel pulse-height analyzers at variable counting rates

Abstract

A new system for automatic correction of dead-time losses of multichannel analyzers is described. Correction is performed by storing compensating pulses distributed over all channels with the same distribution as the measured pulse-height distribution. The integral number of compensating pulses to be stored is derived from comparing the integral number of pulses really stored in the analyzer with the number of detector pulses to be stored. Dead-time losses are corrected accurately not only for constant counting rates, but also if the counting rate is varying during the measurement as long as the pulse-height distribution remains constant. If both, counting rate and pulse-height distribution are varying, dead-time correction is not accurate for very short-lived radionuclides. The limit of this system is only reached at half lifes, some orders of magnitude shorter than with conventional dead-time correction.