A novel method of combined detector model for gamma-ray densitometer: Theoretical calculation and MCNP4C simulation

This study focuses on investigating a new model of combined backscatter and transmission method for nuclear densitometer. In this method for density measurement, a true combination of transmission and backscatter methods was studied and related equations were developed. The MCNP4C code was used for simulation of this combined detector model (CDM) and by applying theoretical calculations, density equation was corrected for the proposed nuclear densitometer. In the new method presented here, the buildup effect was estimated by an online system that was improved in our laboratory and was replaced by a new conceptual calculation. Hence, for the purpose of buildup reduction, there was no need for the shield around the detector, as it was monitored and reduced online. Furthermore, this study showed that the RSQ function could be improved by the CDM. The measurement technique proposed in this study has a better linearity trend than the transmission technique. Thus, the ability of CDM to improve the accuracy of the nuclear densitometer was shown. •Combination of backscatter and transmission methods in nuclear densitometer.•On-line buildup monitoring and on-line buildup reduction.•The error of combined detectors model is less than transmission model.•R-squared value improved in comparison to the transmission technique.•In combination method no shielding needs around the detectors.