Performance studies of boron lined proportional counters for reactor applications

Boron lined proportional counters of standard cylindrical geometry were developed and characterized for reactor applications. It is observed that the life of boron lined proportional counters is significantly lower if irradiated in high neutron flux keeping the HV bias “ON” compared to the irradiation with HV bias “OFF”. When operated in gamma radiation, the boron lined proportional counters suffer count rate loss and underestimate the neutron flux. The loss in the count rate in gamma radiation is attributed to the space charge effect. The space charge effect is theoretically calculated for a known gamma radiation. The estimated values compared well with the experimentally observed values. Neutron sensitivity is estimated by modeling the boron lined proportional counters in FLUKA Monte-Carlo simulation code. The estimated neutron sensitivity values are comparable to the experimental and theoretical values.