Nuclear Techniques ›› 2014, Vol. 37 ›› Issue (07): 70403-070403.

• NUCLEAR ELECTRONICS AND INSTRUMENTATION •

### Measurement of γ absorption dose rate through measuring the full energy peak of γ spectrum

HE Jun1 YANG Chaowen1,2

1. 1(College of Physics Science and Technology, Sichuan University, Chengdu 610065, China) 2(Key Laboratory of Radiation Physics and Technology, Sichuan University, Chengdu 610065, China)
• Received:2014-02-15 Revised:2014-03-16 Online:2014-07-10 Published:2014-07-07
• Supported by:

NSAF

Abstract: Background: At present most radiation dose meters have the serious problem of energy response, and they just use the count rate plus relative correction method to measure the dose rate. This method has large error, and cannot distinguish the type of radionuclide, also cannot obtain the contribution of each radionuclide to the dose rate. Purpose: The research of new method is to measure the dose rate and improve the accuracy of measurement. Methods: The method of γ dose rate measurement through measuring full energy peak of γ spectrum was put forward, the angular response function of parallel γ ray injected into detector was defined. The average angular response over full space in the energy range from 0.02 MeV to 3 MeV was calculated by Monte Carlo simulation for ?50mm×50mm NaI(Tl) detector. Measurement tests have been done using standard radioactive sources of 137Cs, 60Co, 152Eu, 133Ba and in reference radioactive field of 137Cs, 60Co, 226Ra, 241Am in a national lab. Results: The test errors are smaller than 2% compared with the theoretical value for standard sources, and smaller than 3% compared with the value of PTW 10 L spherical chamber for reference radiation field. Conclusion: The results show that the method is suitable for the dose rate measurement for a wide range of energy without experimental calibration, can calculate the dose rate of different energy ray, and at the same time identify the radioactive nuclides in the radiation source.