Efficiency calibration of airborne γ-ray spectrometer using sourceless efficiency calibration method

Based on the exponential law of narrow beam γ ray and calculus principle, a numerical calculation model for sourceless efficiency calibration of airborne γ-ray spectrometer has been developed. Through experiments and simulations, it was found that the relative deviation between the efficiency of airborne γ-ray spectrometer with different surface sources and volume sources and the value of stimulation was within ± 1.5% when conducting low-attitude detection, and the relative deviation between the calculation results of infinite volume source containing 1460.8 keV or 2614.5 keV γ photons at the altitude of 90-150 m and the experimental values was 5.41-11.27%. The above experiments sufficiently proved that sourceless efficiency calibration model could be appropriate for the detection practice of airborne γ-ray spectrometry. (author)