Thin CdTe detector in diagnostic x-ray spectroscopy.

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 gamma rays from the calibration sources (241Am and 133Ba). As spectral distortion due to carrier trapping, known as tailing, was small in gamma-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.