Development of boron-lined ionization chamber used in n/γ mixed field

A boron-lined ionization chamber used in n/γ mixed field with better performance was developed. The boron-lined ionization chamber consists of two cavity rooms with the same size: One is for γ, the other is for both γ and neutron. The neutron sensitivity reaches a level of 9.2×10-16 A/(cm-2·s-1) with a calibrated Am-Be neutron source with neutron intensity estimated to be 2.7×107 s-1, and the γ sensitivity reaches a level of 7.36×10-16 A/(MeV·cm-2·s-1) with a calibrated 137Cs source with 5.24 μGy/h dose rate. The plateau length is 600 V and the slope is less than 4%/100 V. An average γ compensation coefficient is less than 5% at work voltage of-400 V, which can be used to monitor the n/γ mixed field around reactors.