A semiconductor device for fast- and slow-neutron dosimetry

Quantitative observations of pile-neutron effects in germanium and silicon suggest their use as fast-neutron dosimeters, especially in mixed neutron-¿ fields. In order to provide a firm basis for such techniques, or, in other words, to determine neutron-response characteristics of semiconductor materials for general dosimetry applications, more information is needed on the extent to which the damage is actually energy dependent. In the present state of the art, the development of semiconductor dosimeters for fast neutrons of known energy spectrum should be rewarding. On the other hand, it is well known that thermal-neutron captures by lattice nuclei have only a small effect on the electrical properties of germanium or silicon crystals. Slow-neutron reactions yielding fast charged particles or ions may result in enhanced, highly localized damage of practical interest for thermal-neutron dosimetry. A suitable arrangement combining a high-resistivity p-type germanium foil with thin linings of lithium-6 appears to be a convenient tool for the estimation of biologically significant thermal-neutron doses. Analytical and experimental work done on semiconductor dosimeters designed according to the above-mentioned lines is presented.