Comparison of measured and calculated spectra emitted by the X‐ray tube used at the Gustave Roussy radiobiological service

Abstract

Along with the strengthening of the control processes of irradiation systems used in industrial and medical sectors, direct measurement of spectra emitted by X‐ray tubes is becoming a necessity to ensure beam quality. To reach that aim, a research project was initiated at the Henri Becquerel Laboratory to develop a system to measure, with semiconductor detectors (Ge and CdTe), the spectra emitted by X‐ray tubes. However, the measured spectra are distorted by artifacts associated with the detection processes. Therefore, two algorithms were developed to correct for the pile‐up distortions due to the high count rate and for the photon escape phenomenon, which takes place into the crystal of the semiconductor detectors. Our system was tested using the X‐ray tube used by the Gustave Roussy (France) radiobiological service. Measurements with two high voltages (70 and 200 kV) were carried out using a CdTe detector equipped with a micrometric positioning system and a specific collimator to reduce the high count rate. The measured and calculated spectra using the XCOMP5 and SpeKcalc V1.0 programs were compared. This comparison reveals a good agreement. Copyright © 2014 John Wiley & Sons, Ltd.