A processing circuit for overlapped pulse signals for a thermal neutron coincidence counter

We have developed a processing circuit for overlapped pulse signals. The overlapped pulse signals are generated when the pulse signals of a He-3 detector, by using a neutron coincidence counter, are connected to shift register coincidence electronics by an OR gate device. The developed circuit detects the overlapped pulse signals from among four input signals and produces new 50 ns pulse wide signals. We considered a case where two pulse signals are simultaneously overlapped among four signals. This circuit was tested with an ACP safeguards neutron counter (ASNC) for an advanced spent fuel conditioning process (ACP) and a 252Cf neutron source at high rates. The loss rate of the output signal was reduced by 1.27% for singles and 4.75% for doubles when compared with the OR gate device. Also the variation for the triples was much bigger.