EVALUATION OF CDZNTE DETRACTORS FOR SOFT-X-RAY APPLICATIONS

High resistivity CdZnTe is a very promising material for X-ray detecti on at room temperature or slightly below. Cooling a Cd0.8Zn0.2Te cryst al down to -30-degrees-C reduces the leakage current to the picoamp le vel, which enables the use of low-noise pulsed optical feedback instea d of noisier resistive feedback preamplifiers. Also, longer shaping ti me constants at the linear amplifier can be used for the optimum resol ution. We have obtained resolutions of 240 eV (FWHM) for the 5.9-keV F e-55 line at -40-degrees-C and of 282 eV at -30-degrees-C. The Fano fa ctor for the material at -40-degrees-C was calculated to be 0.14. Thes e results compare well with the results obtained with peltier-cooled H gI2 detectors.