2 COGTOT TOTx TOTe TOTx TOTe 15 3

2. COGTOT定位方法(续) • TOTx / TOTe TOTx - TOTe 15

3. 1 方法验证 • 模拟波形加权输出的ASIC——EXYT – 8 x 8 LSYO Array with 4. 1 x 20 mm³ – 8 x 8 Si. PM Array of Sens. L® Micro. FM 30035 – 10000 个有效事件 17

18

• Xpeak / Epeak TOTX - TOTE 19

直接 TOT法 VS COG-TOT • TOTX/TOTE TOTX – TOTE 20

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REFERENCES • [1] Olcott, P. D. , and C. S. Levin. "Pulse Width Modulation: A Novel Readout Scheme for High Energy Photon Detection. " In 2008 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (2008 NSS/MIC), VOLS 1 -9, 3804 -09. NEW YORK: IEEE, 2009. • [2] Deng, Z. et al. “Development of an Eight-Channel Time-Based Readout Asic for Pet Applications. ” IEEE TRANSACTIONS ON NUCLEAR SCIENCE 58, no. 6 Part 2 (2011): 3212 -18. • [3] Shimazoe, K. and H. Takahashi, et al. (2012). "Dynamic Time Over Threshold Method. " IEEE TRANSACTIONS ON NUCLEAR SCIENCE 59 (6 Part 2): 3213 -3217. 26

核电子学实验室 Laboratory of Nuclear Electronics THANKS YOU!

(LEFT) TOT of different pulse amplitude at a fixed threshold Ith=0. 18. (RIGHT) Relationship between TOTX and TOTE with input amplitude from 0. 2 to 1. 0. (The pulse shape is shown in Fig. 1 and the four pulses are multiplied by ωX=1. 0, 2. 0, 3. 0 and 4. 0 for the position X=1, 2, 3 and 4. ) 29

Problems with current ASIC • Mismatch between different channels – Baselines are different • Noise • Input pulse shape 30