We report on the possibility that a new dual-energy X-ray absorptiometry can potentially be designed by Monte Carlo N-Particle (MCNP) simulations to determine the optimal conditions for the thickness of double-layered CdZnTe detector layers and the X-ray tube voltages. The optimal thicknesses of the front and the rear CdZnTe in a detector and an intermediate filter have been determined from transmitted X-ray spectra. In addition, the performance has been tested with a virtual phantom composed of bone and soft tissue. Two types of CdZnTe detectors, one with a single and the other with a 2x2 square array, were simulated with a pencil-type beam of X-rays having spectra generated using the SRS 78 program for 80, 90, 100, 110, and 120 kV. According to the analysis of the relative detection efficiency for X-ray photons for both CdZnTe detectors, the optimum detector-layer thicknesses were found to be 0.5 mm and 3 mm for the front and the rear CdZnTe detectors, respectively, at 120 kV. The X-ray spectra collected from the front and the rear CdZnTe detectors show considerable variability depending upon the locations the beam passes through; the center of a phantom, the boundary between bone and soft tissue, and a soft-tissue-only region. From these results-based MCNP simulations, we suggest that a new bone mineral densitometry sensor based on this double-layered CdZnTe detector has a very promising configuration.
Bibliographical noteFunding Information:
This work was supported by the Nuclear Safety Research Program through the Korea Foundation of Nuclear Safety (KoFONS) using the financial resources granted by the Nuclear Safety and Security Commission (NSSC) of the Republic of Korea (No.1803017).
© 2019, The Korean Physical Society.
- Bone Densitometry
ASJC Scopus subject areas
- Physics and Astronomy(all)