Numerical simulations for diamond sensors as real-time X-ray skin dosemeters; comparison to silicon

Simulation results from Monte Carlo codes developed in our laboratory are used to analyze and improve detector responses against unknown high flux X-ray spectra exposures, as encountered in medicine. The algorithms are applied to diamond and silicon based dosemeters studies. The simulations are focused on real-time skin dosimetry for X-ray energies between 10 and 200 keV. The detector response is simulated as an induced collected charge under high fluence irradiation, to control patient injury. The dose equivalent response at 0.07 mm skin depth is calculated for a large set of diamond sensors. Their sensitivity, accuracy and angular response dispersion are presented. The quasi-tissue equivalent property of the diamond material allows maximum response uncertainties lower than 10% at least up to 75 deg. opening incidences. For such monitors the amount of collected charges shows an asymptotic maximum limit near 80nCSv-1 per mm3 sensor interaction volume. These performances are discussed, and compared to those of silicon diodes