Efficiency of composite boron nitride neutron detectors in comparison with helium-3 detectors

It has been clearly demonstrated that the composite boron nitride (BN) semiconductor polycrystalline bulk detectors with BN grains embedded in a polymer matrix operate as an effective detector of thermal neutrons even if they contain natural boron only. A reasonable signal to noise ratio has been achieved with detector thickness of about 1mm. A Monte Carlo simulation of neutron reactions in the BN detector was done to estimate the thermal neutron detection efficiency. The result was compared with widely used He3 based detectors to prove advantages of BN detectors, which are especially promising for neutron imaging and for large area sensors.