NOVEL PHOTOSENSOR FOR SCINTILLATION CAMERAS

描述（由申请人提供）：自20世纪50年代以来，光电倍增管（PMT）在核医学伽马相机构造中的使用基本上没有变化。最近，包括我们在内的几个小组一直在加紧努力开发各种类型的固态伽马相机，因为它们在性能、尺寸和重量以及成本方面都有很大的改进。迄今为止，基于固态探测器的伽马相机还没有实现所有这些目标，因为迄今为止所探索的固态探测器技术的基本限制。固态光电探测器的性能受到噪声的限制，这是由于它们的电容和漏电流。我们已经取得了重大进展的硅漂移光电探测器（SDP）的发展，直接取代光电倍增管的愤怒相机。这些新探测器的主要优点是其极小的电容（与探测器尺寸无关）和低噪声。然而，到目前为止，这些设备需要大量的冷却（deltaT=50摄氏度）。 在拟议的第一阶段工作中，我们建议研究漂移检测器设计中的一项重大创新，即为漂移检测器增加内部增益。这减轻了漏电流噪声，使得新器件不必被冷却。我们建议在第一阶段制造测试结构，显示该方法的可行性，并在第二阶段完成技术。这种技术将导致大大优于上级性能和低成本相比，其他技术，如APD，PIN二极管，提出作为PMT的替代品在过去。这些新型设备将在第二阶段组装成直径为20 cm的Anger原型相机。 拟定商业应用：这种技术有可能取代与闪烁晶体一起使用的光电倍增管，用于伽马射线光谱学、核医学成像、光子计数等。这些领域的仪器仪表的整体市场价值数十亿美元。这项技术所解决的市场份额高达数亿美元。

DESCRIPTION (provided by applicant):The use of Photomultiplier Tubes (PMTs) in the construction of gamma cameras for nuclear medicine has been largely unchanged since the 1950's. Recently there has been an intensive effort by several groups including ourselves to develop various types of solid state gamma cameras because they offer vast improvements in performance, size and weight, and cost. To date gamma cameras based on solid state detectors have not achieved all of these goals because of basic limitations of the solid-state detector technologies explored so far. The performance of solid-state photodetectors is limited by noise due to their capacitance and leakage current. We have made significant progress on the development of silicon drift photodetectors (SDPs) for direct replacement of the PMT's in Anger cameras. The main advantage of these new detectors is their extremely small capacitance (independent of detector size) and low noise. However until now these devices have needed a large amount of cooling (deltaT=50 degrees C). During the proposed Phase I effort we propose to investigate a significant innovation in drift detector design that adds internal gain to the drift detector. This mitigates leakage current noise so that the new devices do not have to be cooled. We propose to fabricate test structures showing the feasibility of the approach in Phase I and to finalize the technology during Phase II. This technology will result in vastly superior performance and low cost compared to other technologies such as APDs, PIN diodes, proposed as PMT replacements in the past. These novel devices will be assembled into a 20cm diameter prototype Anger camera during Phase II. PROPOSED COMMERCIAL APPLICATION: This technology has potential for replacement of photomultiplier tubes used in conjunction with scintillation crystals for gamma-ray spectroscopy, nuclear medical imaging, photon counting, etc. The overall market for the instrumentation in these areas is in the billions of dollars. The portion of this market addressed by this technology is in the hundreds of millions of dollars.