Given that it is difficult to accurately determine the uranium and thorium contents in the strata of uranium-thorium mixed de-posits,this study developed a digital γ spectrum logging probe based on cerium tribromide(CeBr3)crystals.Using CeBr3 crystals with a diameter of 38 mm×38 mm,the logging probe improved the sensitivity to uranium and the detection efficiency of ore beds with low u-ranium and thorium contents.The logging probe operated as follows.First,the original signals from the CeBr3 detector were filtered and shaped using the C8051 single-chip microcomputer as the core processor.Then,the γ spectrum data were obtained using the energy spectrum collector.After the spectrum unfolding based on the inverse matrix is performed for the γ spectrum data,precise uranium and thorium contents in the ore beds were obtained.Finally,the γ spectrum data were transmitted to the host computer for logging through the RS-485 bus.The results show that the logging probe had high measurement accuracy in the standard uranium-thorium mixed model,with indication errors of less than 6%,stability of less than 1.5%,and repeatability of less than 1%.Moreover,the 2.62 MeV energy peak drift of thorium 208 Tl did not exceed±0.3 channels,and the relative errors of log anomalies were less than 4%.Therefore,the digit-al γ spectrum logging probe proposed in this study is applicable to the exploration and logging of uranium deposits.
γ spectral logcerium bromidespectrum unfolding based on the inverse matrix
万方数据
维普
