ABSTRACT
This chapter describes the response function of a CdTe detector. First, it takes into consideration why the response function is an important parameter for photon-counting x-ray imaging. It then states one strong point for using a photon-counting detector, that scientists can analyze x-ray spectra. The information of the x-ray spectrum is valuable in identifying different materials; therefore, it has the possibility to add new function of the x-ray image, which can be used for medical and industrial applications. For performing precise and accurate material identification, pure x-ray spectra should be measured. Unfortunately, x-ray spectra measured with a spectroscopic detector are not ideal, because the detector has insufficient efficiency. This insufficiency is caused by the interaction between incident x-rays and the detector's materials, which are reflected in the measured spectrum. The chapter explains the concept of the response function and multipixel-type CdTe detector. The chapter explains the response function as a spectrum concerning just one pixel in the two-dimensional detector array.
