Performance of a Prototype Amorphous Silicon Active Pixel Sensor Array using a-Se for Direct X-ray Conversion

摘要

Active pixel sensor (APS) circuits are an alternate to passive pixel sensor (PPS) technology which, when integrated with a direct detection amorphous selenium (a-Se) photoconductor, can enable high performance, digital x-ray imaging applications such as real-time fluoroscopy due to their better signal-to-noise ratios at low dose. This paper presents experimental imaging results from a prototype 64x64 APS pixel array fabricated in a-Si technology. The prototype APS array is coated with a one millimeter thick layer of a-Se and the experimental results are evaluated using a standard radiography x-ray beam quality RQA5. The APS experimental results are compared with a standard real-time detector (FPD14) imaging array under the same x-ray beam conditions. In addition, we will theoretically examine the best achievable performance for our APS array fabricated in state-of-the-art a-Si technology and compare the results to state-of-the-art PPS panels for real-time fluoroscopy.