正电子发射断层成像系统中数字化多通道时间数字转换研究
Multi-channel Digitized Time-to-Digital Converter of Positron Emission Tomography System
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摘要: 利用现场可编程门阵列（FPGA）内部延迟链，对正电子发射断层成像（PET）系统中高精度时间数字转换（TDC）进行研究。采用粗时间和精细时间相结合的方式测量时间，粗时间利用时钟计数器实现，精细时间利用FPGA延迟链实现。测试时间测量的微分非线性和积分非线性，并在双探头PET实验平台上通过时间符合，对系统总体时间分辨进行测试。实验结果表明，TDC时间分辨达79.3 ps，微分非线性为-0.2 LSB/0.2 LSB，积分非线性为-0.2 LSB/0.3 LSB，双探头PET实验系统总体时间分辨达2.1 ns，可满足PET系统对时间测量的要求。Abstract: High precision time-to-digital converter (TDC) in positron emission tomography (PET) system was studied with the delay chains in field-programmable-gate-array (FPGA). Time measurement includes two parts, coarse time measurement implemented by a clock-driven counter, fine time measurement by delay chains in FPGA. Differential nonlinearity (DNL) and integral nonlinearity (INL) were tested, and also, total time resolution of the double-detector PET experimental platform was measured by time coincidence. The results demonstrate that the time resolution of TDC reaches 79.3 ps, and the DNL is between -0.2 LSB and 0.2 LSB, the INL is between-0.2 LSB and 0.3 LSB, the total time resolution of the double-detector PET experimental platform reaches 2.1 ns. Performance of the TDC, implemented in FPGA, can meet the demand of time measurement in PET system.
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[1] RAMIREZ R A, SOONSEOK K, ZHANG Y X, et al. Ultrahigh-resolution L(Y)SO detectors using PMT-quadrant-sharing for human & animal PET cameras[J]. Nuclear Science Symposium Conference Record, 2006, 3: 1 865-1 869. [2] ZHANG Y X, WONG W H. PET resolution and image quality optimization study for different detector block geometries and DOI designs[J]. Nuclear Science Symposium Conference Record, 2007, 4: 2 885-2 888. [3] FENG Changqing, LIU Shubin, AN Qi. Electronics of BESⅢ TOF monitor system[J]. Nuclear Science, 2010, 57(2): 463-466. [4] SONG Jian, AN Qi, LIU Shubin. A high-resolution time-to-digital converter implemented in field programmable-gate-arrays[J]. Nuclear Science, 2006, 53(1): 236-241. [5] WU Jinyuan. Onchip processing for the wave union TDC implemented in FPGA[C] ∥Real Time Conference, RT’09, 16th. US: IEEE， 2009: 279-282.
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