A detailed analysis of the effects of temperature changes, over time and between array elements, on the generation of circular artifacts in images produced by x‐ray computed tomography was reported. We give formulas for calculating—according to the x‐ray energy, detector sensitivity, and observed image quality (contrast and spatial resolution)—the maximum offset temperature coefficient and maximum gain temperature coefficient that will allow circular‐artifact‐free imaging. A temperature‐controlled and insulated solid‐state x‐ray detector array, consisting of Gd2O2S:Pr,Ce,F ceramic scintillators coupled to crystal Si pin‐photodiodes and designed to meet the requirements for these coefficients, produced high‐resolution artifacts‐free CT images of a phantom head.