Readout Circuit System to Improve the Spatial Resolution and Measurable Energy Range of a Compton Camera

In this article, we focus on tackling position distortion in Compton imaging systems by proposing a readout circuit based on a current conveyor. Compton imaging is a technique used for reconstructing radiation source images by analyzing the kinematics of Compton scattering. The accurate positioning of detectors is crucial for achieving high-quality imaging results. However, using a conventional readout circuit coupled with a resistive network to reduce the number of channels can introduce positional distortion in the image, and the amount of distortion depends on the gain of the readout circuit. Therefore, the measurable energy range is limited. In our study, we analyze the factors contributing to position distortion caused by electronic devices and present a novel readout circuit based on a current conveyor. This circuit aims to minimize position error and mitigate the effects of electronic characteristics while controlling the gain of the signal. Experimental verification is conducted using gamma-ray sources to evaluate the proposed readout circuit. The results showed that with 2\times and 10\times gain, the same positional characteristics were found, and the distortion was also greatly improved, approaching the ideal position of the image. It also suggests that the range of measurable energy extends from 80 keV to 1.3 MeV, which could improve the performance of the Compton camera. Overall, our research makes a valuable contribution to the field of Compton imaging. The proposed readout circuit effectively reduces position distortion and expands the measurable energy range, leading to improved performance and reliability of Compton cameras in various applications.