The CdTe detector is a thermoelectrically cooled X-ray detector available in several preamplifier configuration options. The high stopping power of CdTe makes excellent for applications requiring high detection efficiency at energies up to 100 keV. Its performance, small size, and low cost make it ideal for applications including monitoring of X-ray tubes and ED-XRF on the K lines of rare earth metals, lead, gold, uranium, and other high Z materials. The XR-100CdTe is a high performance x-ray and gamma ray detector, preamplifier, and cooler system using 5 x 5 x 1 mm Cadmium Telluride (CdTe) diode detector mounted on a two-stage thermoelectric cooler. The XR-100-CdTe is capable of detecting energies from a few keV to several hundreds of keV, with an efficiency that peaks from 10 to 100 keV. It is fitted with a 1.5-inch extender as standard, with 5 inches and 9-inch extenders available.