Dokhale P, Schmall J, Stapels C, Christian J, Cherry S, Squillante M R, Shah K
Radiation Monitoring Devices, Inc. 44 Hunt Street, Watertown, MA 02472, USA.
Department of Biomedical Engineering, University of California-Davis, Davis, CA 95616, USA.
J Instrum. 2013 Feb;8(2):C02033. doi: 10.1088/1748-0221/8/02/C02033.
We have designed and built a large-area 1cm × 1cm position-sensitive solid-state photomultiplier (PS-SSPM) for use in detector design for medical imaging applications. Our new large-area PS-SSPM concept implements resistive network between the micro-pixels, which are photodiodes operated in Geiger mode, called Geiger Photodiodes (GPDs), to provide continuous position sensitivity. Here we present imaging and timing performance of the large-area PS-SSPM for different temperatures and operating biases to find the optimum operating parameters for the device in imaging applications. A detector module was built by coupling a polished 8×8 LYSO array, with 1×1×20 mm elements, to a 1×1 cm PS-SSPM. Flood images recorded at room temperature show good crystal separation as all 64 elements were separated from each other. Cooling the device at 10 °C showed significant improvement. The device optimum bias voltage was ~4.5V over breakdown voltage. The coincidence timing resolution was improved significantly by increasing the operating bias, as well as by lowering the temperature to 0 °C. Results show excellent imaging performance and good timing response with a large-area PS-SSPM device.
我们设计并制造了一种用于医学成像应用探测器设计的大面积1厘米×1厘米位置敏感型固态光电倍增管（PS - SSPM）。我们新的大面积PS - SSPM概念在微像素之间实现了电阻网络，这些微像素是工作在盖革模式下的光电二极管，称为盖革光电二极管（GPD），以提供连续的位置敏感性。在此，我们展示了大面积PS - SSPM在不同温度和工作偏压下的成像和定时性能，以找到该器件在成像应用中的最佳工作参数。通过将一个经过抛光的8×8 LYSO阵列（元件尺寸为1×1×20毫米）与一个1×1厘米的PS - SSPM耦合，构建了一个探测器模块。在室温下记录的泛光图像显示出良好的晶体分离效果，因为所有64个元件都相互分离。将器件冷却到10°C显示出显著改善。该器件的最佳偏压约为击穿电压之上4.5V。通过增加工作偏压以及将温度降低到0°C，符合定时分辨率得到了显著提高。结果表明，大面积PS - SSPM器件具有出色的成像性能和良好的定时响应。
