Composite polycrystalline boron nitride for alpha and neutron detectors

Hexagonal Boron Nitride polycrystalline material can act as semiconductor neutron detector which converts neutrons to alpha particles as a result of the neutron reaction with ¹⁰B. Therefore by testing for the response to alpha radiation BN or any other similar compounds, which have a relative large cross section to absorb neutrons; one can obtain a preliminary indication on its ability to detect neutrons. Among the successful compounds we studied and reported here is composite BN. The polycrystalline studied BN were bound as planar detectors with different binders, such as Polystyrene or Nylon-6, and coated with different metal electrodes such as ITO, Aquadag, Al and Cu. The planar BN detector plates which contained initially only the natural amount of the active ¹⁰B of 20% were further diluted by the binder to only 10% of ¹⁰B. Despite the low content of neutron active conversion isotope and very low signal to noise (S/N) ratio of about 2, the neutron caused events could be counted by subtracting the noise from the signal. In addition, the BN was also irradiated on an intensive neutron beam and the results will be shown.