Experimental and theoretical study of long counters on the departure of “point” assumption and scattering background influence

A new long counter has been constructed and calibrated with the inherent efficiency of 11.5 cm2 in the 2.5 MeV neutron field, and a relative flat energy response of 20% disparity within 0.5 MeV–15 MeV. Using this detector and another commercial DePangher counter, the departure of “point” assumption at near distance and the scattering background influence are investigated by performing three groups of experiments in low, middle and high scattering room. Simulation studies are also performed to supplement the experimental data.