The use of nuclear simulation calculations to support applications in radioactive tracer logging

A method for simulating the pulse height responses of passive gamma-ray spectroscopy logging tools is described, and its application to measurements of radioactive tracer spectra is demonstrated. This method consists of computing the flux at the detector surface, convolving the flux with the detector response computed in a separate step to obtain a base spectrum, convolving the base spectrum with itself to obtain a spectrum representative of the contribution due to random summing, and adding the sum spectrum to the base spectrum to obtain the final spectrum. Comparison of measured and simulated spectra and the Compton ratio derived from the measured and simulated spectra for several radioisotopes demonstrates the accuracy of the simulation method. This method has been used to compute calibration spectra for a large number of radioisotopes for which calibration measurements had not been made