Method and device for simulating detection efficiency of calibration detector by adopting virtual source

Abstract

The invention provides a method and device for simulating detection efficiency of a calibration detector by adopting a virtual source. The virtual source is used for replacing gas for efficiency calibration, and the efficiency split principle, an collimation conical point source and a virtual point source in a Monte Carlo program and a line source are ingeniously applied to aerial survey Monte Carlo calibration simulation work. The method and device can replace a body source to do the daily calibration work of labs and field instruments, that is, energy calibration and efficiency calibration are achieved through one-time experiment calibration, and therefore calibration work links are reduced, and source purchasing cost is lowered.

Description

technical field [0001] The invention belongs to radiation detection technology and method, and in particular relates to the detection efficiency calibration technology of detectors and the virtual technology of radioactive sources. Background technique [0002] This patent mainly studies the efficiency calibration work in laboratory and field measurement environments of radioactive substances. The efficiency scale of the detector is classified into three technical methods from the broad aspects: active efficiency scale, passive efficiency scale, and active and passive hybrid scale. The main methods of active efficiency calibration include standard source relative calibration method and semi-empirical formula function method. Passive efficiency calibration mainly includes Monte Carlo simulation, software efficiency calibration and mathematical theoretical calculation. Active and passive hybrid calibration methods mainly include efficient transfer method, Virtual point detect...

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Problems solved by technology

[0007] However, the most fatal congenital deficiency of passive scales is that the correctness and reliability of the scale results cannot be guaranteed. When the measurement environment changes or the use time is long, the verification of active scales must be carried out.

[0008] The biggest advantage of the active efficiency scale is that its correctness and reliability are guaranteed, but most of the active efficiency scales are aimed at volume sources, and its disadvantages are: the geometric shape and component density of the volume source are difficult to be consistent with the standard source , the correction is cumbersome and time-consuming; the preparation of the standard source is complicated, expensive, and complex samples are not easy to prepare; it is necessary to apply for a radioactive source license, and it cannot be used in time in emergency situations; if the half-life of the standard source is short, its use time is too short; Time-consuming and safety issues, resulting in a small range of application of standard volume sources for calibration

The adjoint Monte Carlo method is the inversion of the physical process, and the reverse simulation of particle transport requires an adjoint equation, which is difficult to program; the point flux point probability method does not actually transport the particles to the detection point, but only estimates the point flux and cannot further simulate the response in the detector, so it cannot meet more practical needs

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