Xenon source virtual point source scale device and method based on point source efficiency function

Abstract

The invention provides a xenon source virtual point source scale device based on a point source efficiency function. The device comprises radioactive xenon sources, a standard mixing point source and a detector; the radioactive xenon sources are located at different heights over the detector; the standard mixing point source is located at the corresponding height over the detector; energy of rays emitted by the standard mixing point source must cover or approach to energy of rays emitted by the radioactive xenon sources. The 170Tm point source of long half-life is selected to be placed at the virtual point position of a 133Xe and isotope gas source of short half-life to simulate the efficiency of the scale radioactive 133Xe sources, and the problem that as some standard 133Xe and isotopes are short in half-life in actual working process, the use time is short can be solved.

Description

technical field [0001] The invention belongs to radiation detection technology, and in particular relates to a point source efficiency function calibration technology of a detector and a virtual point source technology of a radioactive source. Background technique [0002] Measuring xenon gas usually uses planar HPGeγ energy spectroscopy. The HPGe gamma energy spectroscopy method determines the activity by xenon isotope characteristic gamma rays. This method has simple equipment and high energy resolution, and is widely used in nuclide laboratories in various countries. The key to the HPGe gamma energy spectroscopy method is to determine the detection of the xenon radioactive source by the detector. efficiency. [0003] Chinese invention patent 201310617130.5 a method and device for calibrating xenon sample HPGe detection efficiency and 201310294436.1 surface source automatic simulation calibration gas source detection efficiency method and device system, mainly using surfa...

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Problems solved by technology

[0003] Chinese invention patent 201310617130.5 a method and device for calibrating xenon sample HPGe detection efficiency and 201310294436.1 surface source automatic simulation calibration gas source detection efficiency method and device system, mainly using surface source calibration radioactive xenon gas source efficiency, the disadvantage of using surface source is Its diameter must be consistent with the diameter of the gas source to be simulated, and it can only simulate a fixed-shaped gas source such as a cylindrical gas source. At the same time, the uniformity requirements of the surface source are also high, and the production cost is high.

[0004] Chinese invention patent 201410264382.9 uses a method and device for simulating the detection efficiency of a virtual source to simulate a scaled detector, and proposes the theory of a virtual point source and a virtual surface source with a scaled radioactive xenon gas source, but it does not solve the problem of determining the position of the virtual source.

This patent mainly finds the position of the virtual source by making a standard gas source and Monte Carlo simulation. The cost of making a standard radioactive gas source is very high, and the service life is also very short. The calculation error of the Monte Carlo simulation is large because the calculation parameters cannot be guaranteed, and It is not a substitute for daily efficiency tick work

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