Gaussian broadening and spectrum unfolding method of gamma response function of detector

Abstract

The invention discloses a Gaussian broadening and spectrum unfolding method for a gamma response function of a detector, which comprises the following steps of: firstly, performing Gaussian broadening on each energy point in a certain unbroadened energy spectrum by adopting Gaussian broadening of an analytical method according to a relationship between full width at half maximum and energy to obtain a response function under a specific energy resolution; secondly, broadening the unbroadened energy spectrums of the incident photons with different energies in sequence by using an MATLAB batch processing program to obtain a response matrix formed by response functions under different energies; and finally, solving the mixed gamma energy spectrum by using a weighted least square method in combination with the response matrix. According to the method, the response matrix broadened by the analytical method is reliable, after the change of the energy resolution of the mixed spectrum is simulated, the fluctuation of solving the mixed spectrum by the response matrix under the corresponding energy resolution is small, the accuracy is high, and the solving effect of the weighted least square method under the corresponding energy resolution is good. Gaussian broadening is carried out by adopting an analytical method, broadening parameters can be adjusted according to reality, and a more convenient mode is provided for constructing a response matrix under the corresponding energy resolution.

Description

technical field [0001] The invention belongs to the technical field of gamma energy spectrum analysis, in particular to a method for Gaussian broadening and spectrum resolution of a gamma response function of a detector. Background technique [0002] Gamma energy spectrum analysis is widely used in geological exploration, national defense security, environmental monitoring, aerospace and other fields. Corresponding physical information can be obtained from the measured mixed γ energy spectrum. Accurately obtaining the detector's response to γ-rays is a research The core problem of gamma spectrum. The current methods for studying the γ-ray response function mainly include (1) combining standard samples and experimental determination; (2) interpolating on the basis of known response curves of certain monoenergetic nuclides; (3) using the Monte Carlo sampling method Combined with the physical process and cross-sectional information of the interaction between rays and matter, t...

AI Technical Summary

Problems solved by technology

In the current method, it is difficult to find various single-energy standard sources by experimental methods, and the input cost is high; and the accuracy of interpolation results based on certain nuclides is affected by the interpolation method, which makes the Monte Carlo method a research response. Important methods of functions

Using the Monte Carlo method to simulate and calculate the response function needs to set the energy resolution according to the actual situation. At present, the energy resolution parameters of the detector are set in most cases by using the GEB card that comes with the MCNP. This method It is very convenient under ideal conditions, but there are also the following problems: since the energy resolution of the detector is easily affected by factors such as temperature, electronic system, and the geometric size of the radioactive source, when the energy resolution changes, the response function will also change. The change requires re-simulation calculations, and when there are many elements in the response matrix, re-simulation requires more time and cost

Therefore, when the energy resolution of the detector changes, the gamma response matrix obtained by the original simulation using the Monte Carlo method is not available, resulting in inaccurate gamma spectrum resolution

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