CdZnTe detector in diagnostic x-ray spectroscopy

A method to utilize CdZnTe (CZT) detectors in diagnostic x-ray spectroscopy is described in this article. Spectral distortion due to transmission of primary x rays, the escape of cadmium- and tellurium-K fluorescent x rays, and tailing was severe in measured x-ray spectra. Therefore, correction for the distortion was performed with the stripping method using response functions. The response functions were calculated with the Monte Carlo method. The Hecht equation was employed to approximate the effects of carrier trapping in the calculations. The parameters in the Hecht equation, the mean-free path (lambda) of electrons and holes, were determined such that the tailing in calculated response functions fit that in measured gamma-ray spectra. Corrected x-ray spectra agreed well with the reference spectra measured with an HPGe detector. The results indicate that CZT detectors are suitable for diagnostic x-ray spectroscopy with appropriate corrections. (C) 2002 American Association of Physicists in Medicine.