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 αʹs 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.