Pulsed Neutron Monitoring at High Energy Electron Accelerators with Silver Lined Proportional Counter

Abstract

To meet the challenging requirement of pulsed neutron background measurement, which is present around electron accelerators at the Indus‐1 facility of the Raja Ramanna Centre for Advanced Technology (RRCAT) Indore, a silver lined proportional counter with 0.2cps/n cm−2s−1 thermal neutron sensitivity has been developed. The detector has been tested for its performance in continuous thermal neutron field at Apsara reactor and in pulsed neutron field at Indus‐1 facility. The detector shows ±11% signal linearity at various reactor powers and follows the silver decay scheme during reactor scram experiment. Off‐line measurements made in pulsed neutron background at the Indus‐1 facility compare well with nuclear track detectors (CR‐39). For monitoring on‐line neutron flux, electronic gating circuit was used that can switch off the scalar counter unit during the prompt X‐ray response of the detector taking trigger pulse from the accelerator and experiments showed that the neutron flux measured by the detector is in close agreement with CR‐39 values.