THE USE OF HYDROGENOUS MATERIAL FOR SENSITIZING PMOS DOSIMETER TO NEUTRONS

This paper is concerned with the application of pMOS dosimeters to mea suring neutron dose by the use of hydrogenous materials to convert inc ident neutron flux to recoil protons. These latter charged particles c an generate electron-hole pairs, and consequently, charge trapping tak es place at the MOS interfaces, and threshold voltage shifts are produ ced. The use of pMOS devices for measuring gamma doses has been descri bed extensively in the literature. Clearly, if measurable voltage shif ts could be generated in a MOS device by neutrons, then a radiation de tection instrument containing two MOS devices, back to back, with hydr ogenous shields, and one MOS dosimeter without a converter would allow 4pi measurements of neutron and gamma doses to be made. The results o btained in this study indicate that paraffin or polyethylene will conv ert incident, 2.82 MeV neutrons to recoil protons, which subsequently cause measurable voltage shifts.