On density measurement using various radiation sources: Cs-137, X-ray and pulsed neutron

The use of controllable sources for density measurement is gaining more attention as a safer alternative to chemical sources, since chemical sources pose risks to both humans and the environment. Nuclear density tools using electronically controlled sources, such as X-ray tubes and pulsed neutron generators, are being researched as a replacement for radiological gamma sources such as Cs-137. This study, based on the real gamma density tool structure, optimizes the design of the X-ray and pulsed neutron-gamma density tools, providing a reference for the optimization of source-less density tools. Firstly, the study gives a comparison of density measurement using three sources through a combination of theory and simulation results. And the performance of the tools is evaluated using indicators such as detection efficiency, formation density sensitivity, and depth of investigation. Finally, based on the characteristics of different sources, the aforementioned indicators are balanced to obtain the optimal value of the source-to-detector distance, thus the structure of the X-ray density tool and pulsed neutron-gamma density tool are optimized.