CIX - A Detector for Spectral Enhanced X-ray Imaging by Simultaneous Counting and Integrating

TL;DR

This paper introduces a hybrid X-ray detector combining photon counting and charge integration to extend dynamic range and enable spectral imaging, demonstrated with prototype CMOS chips using different sensor materials.

Contribution

The paper presents a novel hybrid detector that integrates counting and integrating methods, allowing high dynamic range imaging and spectral analysis in X-ray detection.

Findings

Extended dynamic range through combined counting and integrating.

Spectral information enhances X-ray image contrast.

Prototype demonstrates effective performance with different sensor materials.

Abstract

A hybrid pixel detector based on the concept of simultaneous charge integration and photon counting will be presented. The second generation of a counting and integrating X-ray prototype CMOS chip (CIX) has been operated with different direct converting sensor materials (CdZnTe and CdTe) bump bonded to its 8x8 pixel matrix. Photon counting devices give excellent results for low to medium X-ray fluxes but saturate at high rates while charge integration allows the detection of very high fluxes but is limited at low rates by the finite signal to noise ratio. The combination of both signal processing concepts therefore extends the resolvable dynamic range of the X-ray detector. In addition, for a large region of the dynamic range, where counter and integrator operate simultaneously, the mean energy of the detected X-ray spectrum can be calculated. This spectral information can be used to enhance the contrast of the X-ray image. The advantages of the counting and integrating signal processing concept and the performance of the imaging system will be reviewed. The properties of the system with respect to dynamic range and sensor response will be discussed and examples of imaging with additional spectral information will be presented.