Design and Performance of a Resistor Multiplexing Readout Circuit for a SiPM Detector
Design and Performance of a Resistor Multiplexing Readout Circuit for a SiPM Detector
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DOI：
10.1109/tns.2013.2251661
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发表时间：
2013-06-01
影响因子：
1.8
通讯作者：
Thompson, Christopher J.
中科院分区：
文献类型：
--
作者：
Goertzen, Andrew L.;Zhang, Xuezhu;Thompson, Christopher J.
研制了一种基于硅光电倍增管（SiPM）的正电子发射断层扫描（PET）探测器，该探测器采用电阻网络电荷分割多路复用电路进行探测器读出。该检测器由氧正硅酸镥钇（LYSO）闪烁晶体阵列、SiPM阵列检测器（SPMArray 4，SensL Inc.，Cork，爱尔兰），以及在通孔封装中实现的电阻器多路复用网络，以便于改变电阻器值。为了优化读出电路，所使用的LYSO阵列是4 × 4晶体阵列，晶体尺寸为3.17 × 3.17 × 10 mm（3），间距为3.37 mm，与SiPM像素尺寸匹配。使用标准NIM电子设备进行洪水图像、能量分辨率、峰值幅度、定时分辨率和信号时间拾取测量。通过迭代过程优化电阻网络值。通过加热检测器，在23 ° C至60 ° C的温度范围内评估检测器的性能。使用具有1.67 mm间距的晶体的双层LYSO阵列来评估检测器分辨小于SiPM像素间距的晶体的能力。发现最佳电阻器网络值为沿连接SiPM像素的行沿着为100 Ω，且沿列为56 Ω。对于这些电阻值设置，阵列中中心四个晶体的平均能量分辨率在23.5 ℃时为13.3% +/- 0.3%，在60 ℃时降低到16.3% +/- 0.3%。在此温度范围内，对于350-750 keV的能量窗口，峰值幅度降低了2%摄氏度，定时分辨率从3.43 +/-0.22 ns降低到4.64 +/- 0.25 ns。随着温度的升高，信号时间拾取点提前了2.7 ns，这可能是由于信号形状随温度变化而产生的影响。该检测器能够分辨双层LYSO阵列中的所有113个晶体。这些结果表明，电阻器复用读出电路对于阅读基于SiPM阵列的检测器功能良好，所述基于SiPM阵列的检测器使用比SiPM像素间距小得多的闪烁体晶体阵列。通过这种信号多路复用实现的输出信号数量的减少大大减少了所需的信号电缆的数量。此外，该检测器在宽温度范围内运行的能力为定义系统工作温度设定点提供了极大的灵活性。
A silicon photomultiplier (SiPM)-based positron emission tomography (PET) detector was developed using a resistor network charge division multiplexing circuit for detector readout. The detector consists of a lutetium-yttrium oxy-orthosilicate (LYSO) scintillation crystal array, an SiPM array detector (SPMArray 4, SensL Inc., Cork, Ireland) and the resistor multiplexing network implemented in a through-hole package to facilitate changing of resistor values. For purposes of optimizing the readout circuit, the LYSO array used was a 4 x 4 crystal array with crystal size 3.17 x 3.17 x 10 mm(3) on a pitch of 3.37 mm, matched to the SiPM pixel size. Flood image, energy resolution, photopeak amplitude, timing resolution, and signal time-pickoff measurements were performed using standard NIM electronics. The resistor network values were optimized through an iterative process. The performance of the detector was evaluated over a range of temperatures from 23 degrees C to 60 degrees C by heating the detector. The ability of the detector to resolve crystals smaller than the SiPM pixel pitch was evaluated using a dual-layer LYSO array with crystals of 1.67-mm pitch. The optimal resistor network values were found to be 100 Omega along the rows connecting the SiPM pixels and 56 Omega for the columns. For these resistor value settings, the average energy resolution for the central four crystals in the array at 23.5 degrees C was 13.3% +/- 0.3% and degraded to 16.3% +/- 0.3% at 60 degrees C. The photopeak amplitude decreased by 2% degrees C, and the timing resolution degraded from 3.43 +/- 0.22 ns to 4.64 +/- 0.25 ns for a 350-750-keV energy window over this temperature range. The signal time-pickoff point shifted earlier by 2.7 ns as the temperature increased, an effect likely due to changes in the signal shape with temperature. The detector was able to resolve all 113 crystals in the dual-layer LYSO array. These results demonstrate that the resistor multiplexing readout circuit functions well for reading out SiPM array based detectors, which use scintillator crystal arrays much smaller than the SiPM pixel pitch. The reduced number of output signals achieved through this signal multiplexing greatly reduces the number of signal cables required. In addition, the ability of this detector to function over a wide range of temperatures offers significant flexibility in defining the system operating temperature set point.