Measurement of X-ray spectrum using a small size CdTe multichannel detector

A multichannel detector was fabricated with 32 elements, each 1 mm wide×0.25 mm long×0.3 mm thick, on a single CdTe crystal wafer whose overall size was 1×8×0.3 mm. One of the elements was subjected to an energy analysis using diagnostic wavelength X-rays. It is noted that the energy spectrum was distorted because of the small size of the element. Errors caused by X-ray escape and by the energy dependency of the photoelectric absorption process were appreciable; however, these errors are specific to narrow energy ranges and can be corrected. The response function of the detector to monochromatic 59.54 keV ²⁴¹Am gamma-rays was measured and, by fitting the results to a calibration curve, this small-size CdTe detector was able to detect X-ray spectra reliably