JPS54141185A - Radiation detector - Google Patents

Abstract

PURPOSE: To enable the sensitivity calibration of a neutron measuring radiation detector to be performed simply and surely by providing a mixture layer comprising mixing a slight amount of radioactive isotope into solid state fissionable material in a case and opposing the detecting part to the mixture layer.

CONSTITUTION: A mixture layer 1 comprising mixing a slight amount of radioactive isotope, e.g., ²⁴¹Am to solid state fissionable material, e.g, ²³⁵U and a semiconductor detecting part 2 opposing thereto are sealed in a case 3 connected to a power source 4. The neutrons having arrived at this radiation detector enter the layer 1, where ²³⁵U causes unulear fission and the fission fragments enter the detector 2 by having the kinetic energy of 60 to 100MeV, whereby output pulses are generated. On the other hand, in the place where no neutrons exist, the output pulses are generated by α rays such as 4.39MeV, etc. at which ²³⁵U releases. When the count rate is low, the output pulses are generated by α rays of about 5.5MeV at which readily separated ²⁴¹Am releases. These output pulses are counted via preamplifier 5 and amplifier 6.

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