Pulse Height, Pulse Shape, and Time Interval Analyzer for Delayed $\alpha /\beta$ Coincidence Counting

Abstract

In this paper, we present a newly constructed analyzer dedicated to measuring the activity of a variety of radioisotopes with an emphasis on the delayed coincidence method. The analyzer acquires arriving pulses whose amplitudes exceed the preset voltage threshold by selectively storing the sampled incoming voltage pulses. This creates data sets that are marked with additional time stamps. These data are given as a sequence, allowing the detection of decay pairs and different types of afterpulses or reduction of the detector's background. Here, the pulse analyzer was verified with a thick α and β sources from <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">232</sup> Th and <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">238</sup> U decay chains and a β source from 40K. The simultaneous pulse height, pulse shape, and time interval measurement allowed the differentiation of β/α pulse pairs arising from <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">212</sup> Bi/ <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">212</sup> Po, <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">214</sup> Bi/ <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">214</sup> Po decay pairs with 300 ns and 160 μs polonium half-life, respectively.