Composite polycrystalline semiconductor neutron detectors

Composite polycrystalline semiconductor detectors bound with different binders, both inorganic molten glasses, such as B₂O₃, PbO/B₂O₃, Bi₂O₃/PbO, and organic polymeric binders, such as isotactic polypropylene (iPP), polystyrene or nylon-6, and coated with different metal electrodes were tested at room temperature for α-particles and very weak thermal neutron sources. The detector materials tested were natural occurring hexagonal BN and cubic LiF, where both are not containing enriched isotopes of ¹⁰B or ⁶Li. The radiation sources were 5.5 MeV α's from ²⁴¹Am, 5.3 MeV from ²¹⁰Po and also 4.8 MeV from ²²⁶Ra. Some of these detectors were also tested with thermal neutrons from very weak ²²⁷Ac⁹Be, ²⁴¹Am-¹⁰Be sources and also from a weak ²³⁸Pu+⁹Be and somewhat stronger ²⁵²Cf sources. The neutrons were thermalized with paraffin. Despite very low signal to noise ratio of only ∼2, the neutrons could be counted by subtracting the noise from the signal.