Direct detection of long-duration intense X-ray fluxes with SiPM

Abstract

In standard applications Silicon Photomultipliers (SiPMs) are usually used for the detection of photons in the infrared to near-ultra violet range or coupled to scintillators to detect higher energy photons or charged perticles. In this work we demonstrate that SiPMs can be used in current mode, measuring the SiPM DC current, to directly detect with high precision long and intense X-ray fluxes in the energy range ∼ 3 ÷ 15 keV . The response factor of the SiPM to X-rays has been determined and the intrinsic saturation current estimated. Furthermore the attenuation length of X-rays in air has been measured exposing the SiPM to a X-ray flux, confirming the validity of the methods. These results indicate that the SiPM device can in principle be calibrated to perform real time measurements in a high intensity X-ray flux environment and that the SiPM DC current is a potential dosimetric variable for online monitoring of X-ray fluxes.