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

Johann Plagnard (1)

1 LNHB - Laboratoire National Henri Becquerel

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.

Keywords: photon dosimetry; spectra emitted by X-ray tubes; CdTe detector; correction algorithm against escape phenomenon; Pile-up distortion; Spectra analysis; Pile-up correction; Radiobiology/dosimetry; Collimator design

Domains: Nuclear Experiment [nucl-ex]; Instrumentation and Detectors [physics.ins-det]

Johann Plagnard. Comparison of measured and calculated spectra emitted by the X-ray tube used at the Gustave Roussy radiobiological service. X-Ray Spectrometry, 2014, 43 (5), pp.298 - 304. ⟨10.1002/xrs.2554⟩. ⟨cea-01863523⟩