Nuclear Techniques ›› 2019, Vol. 42 ›› Issue (7): 0-070202-4.doi: 10.11889/j.0253-3219.2019.hjs.42.070202

• ACCELERATOR, RAY TECHNOLOGY AND APPLICATIONS •    

A high sensitivity screening method for γ peaks based on the critical level

Xinjun ZHANG,Shilian WANG,Huaimao JIA,Qi LI,Jianfang SHI,Yuanqing FAN,Yungang ZHAO   

  1. CTBT Beijing National Data Centre and Radionuclide Laboratory, Beijing 100085, China
  • Received:2019-03-18 Revised:2019-04-28 Online:2019-07-10 Published:2019-07-16
  • About author:ZHANG Xinjun, male, born in 1976, graduated from China Institute of Atomic Energy with a doctoral degree in 2018, focusing on particle physics and nuclear physics

Abstract: Background

Radionuclide monitoring is critical to determine whether a suspicious nuclear event detected is a nuclear explosion test. Trace released radionuclides will be transported in the atmosphere, their decay and dilution induce that comprehensive nuclear-test-ban treaty (CTBT) relevant radionuclide monitoring belongs to the ultra-low level radioactive monitoring. The weak γ peaks of CTBT relevant radionuclides are interfered by the complex high environment radioactivity background.

Purpose

This study aims to search accurately the weak γ peaks of CTBT relevant radionuclides in γ spectra of aerosol samples from CTBT radionuclide stations.

Methods

A screening method for γ peaks based on the critical level was proposed to detect weak γ peaks immerged in high environmental radioactive background. Combining the second derivative peak finding method, accurate detection for γ peaks was achieved. Finally, verification was performed on HPGe γ spectra from CTBT radionuclide stations.

Results

The identification rate of γ peaks by using proposed method is 97.4% and the error identification rate of γ peaks can be reduced from 274% to 10.4%.

Conclusion

The high sensitivity screening method for γ peaks based on the critical level can improve the accurate detection rate of the weak γ peaks.

Key words: CTBT, γ peak, Critical level, Screening method

CLC Number: 

  • TL816.4