Double and Triple Coincidence Counter With More Than Three Photosensors and Independent Coincidence Counting

A double and triple coincidence counter using more than three photosensors was developed. The principle of operation and measurement is based on the well-established statistical model governed by the Poisson stochastic model. Design features to optimize the efficiency of the counters are presented. The photosensors of these counters are grouped in subsets. The double and triple coincidences can be measured simultaneously for all subsets. The results of these measurements are used to verify the proper operation of each coincidence counter. In addition, the recorded coincidence counting rates are used to estimate the rate of interaction of the radiation with the scintillator. Preliminary measurements were performed to verify the proper operation of a coincidence counter with four photosensors. A measurement of a
$^{14}\text{C}$
reference source resulted in an estimation of the
$^{14}\text{C}$
decay rate remarkably close to the specified reference disintegration rate. A scintillation source combining55Fe and plastic scintillator BC-412 was used to verify the counter operation at a weak scintillation output of less than 60 photons per photoelectron interaction with the scintillator.