The use of scintillators based on complex heavy oxides for detection of neutron fluxes

Abstract

Studies are reported on the possibility of detection and spectrometry of thermal and resonance neutrons using crystals based on complex oxides. The crystals studied included CWO, GSO(Ce), NBWO, polycrystals LuSO(Ce), comprising elements Cd, Gd, W, Lu, Na with large capture cross-section of thermal and resonance neutrons. Energy spectra have been studied for products of nuclear reactions of internal conversion electrons (ICE), KX- and gamma-quanta in said compounds. A possibility has been shown in principle of spectrometry of thermal neutrons on nuclei of the said elements in different energy ranges, with exception of /sup 176/Lu nuclei. The presence of radiation background froth the nuclei of natural radionuclide /sup 176/Lu, as well as high induced activity due to radiation neutron capture, can be additional sources of the background. Induced activity spectra were studied for NBWO crystals, and possibilities are discussed of their use as elements of optical system of combined neutron detectors. A possibility is shown to discern products of neutron radiation capture nuclear reactions on nuclei of cadmium, tungsten, gadolinium. This is achieved by means of selected energy detection windows for nuclear reaction products and accompanying gamma-radiation, using scintillators with different response times and interaction cross-sections with neutrons and gamma-quanta, as well as using screens that selectively absorb neutrons or gamma-quanta.