Thin CdTe detector in diagnostic x-ray spectroscopy

Abstract

A CdTe Schottky diode detector of 1 mm thickness was employed in diagnostic x-ray spectroscopy. The detector response to monoenergetic photons was investigated with γ rays from the calibration sources (241Am and 133Ba). As spectral distortion due to carrier trapping, known as tailing, was small in γ-ray spectra, the effects of carrier trapping were not taken into account in the calculation of response functions. The distortion due to the transmission of primary x rays and the escape of secondary x rays (K-fluorescent x rays and Compton-scattered x rays) from the crystal was included in the calculated response functions. X-ray spectra corrected using the response functions were in good agreement with the reference spectra obtained with a high-purity germanium detector. The results indicated that correction for the distortion due to carrier trapping is not necessary when using a thin CdTe detector in diagnostic x-ray spectroscopy. © 2003 American Association of Physicists in Medicine.