Feasibility study of the use of a silicon photomultiplier coupled to a scintillator for kVp measurement based on spectrometry

Abstract

This study proposes a spectroscopic and non-invasive approach to measure the kVp of an X-ray tube using a silicon photomultiplier (SiPM) coupled to a GaGG scintillator crystal. Several experimental setups were explored to assess the feasibility and performance in measuring the kVp based on international standards IEC 61267:2005 and IEC 61676:2002. The energy spectrum was obtained through pulse height analysis. System calibration was performed using radioactive sources emitting characteristic X-rays and gamma radiation. Determination of the maximum energy of the X-ray spectrum was based on a linear regression aiming for a goodness of fit to reduce uncertainty in kVp. The approach was successfully evaluated for specific radiology beams, including mammography, with a maximum uncertainty of 6.5% in the kVp values for the tested beam qualities.