Abstract: The present invention is directed to a nuclide separation precipitator system in which noble gas nuclear fission products are introduced into a gas reservoir and generate charged daughter nuclides in the gas reservoir. A collector collects three detectable charged daughter nuclides. A detector detects the energy distributions of beta-rays and gamma-rays emitted from the daughter nuclides collected in the collector and outputs signals indicative of the detected beta-rays and gamma-rays. Three pulse height discriminators discriminate the signals output from the detector into three respective energy levels of a low energy range, a middle energy range, and a high energy range. A first order simultaneous equation of three unknowns obtained by utilizing a fact that counting ratios of the three energy ranges vary for each daughter nuclide is then solved.

Abstract: A semiconductor radiation detector is equipped with a semiconductor detection device such as silicon or germanium and is used in qualitative and quantitative analysis of X-rays or gamma-rays while the detection device is cooled with a refrigerator that makes use of the adiabatic expansion of air or nitrogen gas being released from an adiabatic expansion valve. In accordance with the present invention, the periphery of the gas outlet of the adiabatic expansion valve at the tip of the refrigerator is covered with a gas-permeable fibrous or screen-like material or with a laminate of two or more perforated plates. This construction ensures a passage of gas flow and yet reduces the air vibration that would otherwise occur when the gas is released from the adiabatic expansion valve. The detector of the present invention provides an energy resolution that is just comparable to the value attained when the detector is cooled directly with liquid nitrogen.