Development of Photo-sensors for 1 Megaton size Proton Decay and Neutrino Detectors

该研究项目的目标是为下一代1兆吨级质子衰变/中微子探测器开发新的光传感器。传感器的要求是便宜的，并具有良好的镀锡/充电分辨率。研制了13英寸的混合光电探测器样机，并进行了详细的测试和改进。以下是我们遇到的问题和解决方案的列表。1.由于施加到雪崩二极管（AD）的25 kV放电。→在制作光电阴极材料时加热支撑绝缘体。2. AD寿命短。→开发长寿命5 mm φ AD 3，有效光电阴极面积为300 mm中的240 mm。→ AD位置和光阴极表面形状的微调。4. HPD结构优化→制定优化方案，最大限度地减少零件数量，提高耐压性和光阴极表面形状。从以上研究可以看出，大尺寸HPD具有优良的特性。(good定时/电荷分辨率）并且没有大的技术问题。我们将进一步优化HPD的设计，并通过扩大探测器尺寸来降低成本。

The goal of this research project is to develop new photo sensors for next generation 1Megaton size proton decay/neutrino detectors. Requirements of the sensor are cheap and having good tinning/charge resolutions. We developed 13inch size prototype of hybrid photo detector (HPD) and performed detailed tests and several, improvements. Here is the list of problems and solutions we reached.1.electric discharge due to 25kV applied to avalanche diodes (AD). → heat up a support insulator when making photo cathode material.2.short lifetime of AD. → develop long life 5mmφ AD3.effective photo cathode area is 240mm out of 300mm. → fine tuning of the position of AD and the shape of the photo cathode surface.4.optimization of HPD structure → made optimization plan to minimize the number of parts and improve the pressure resistance and the shape of the photo cathode surface.From the research above, we conclude that large size HPD has excellent characteristics. (good timing/charge resolution) and there is no big technical problems. We would perform further optimization of the HPD design and cost reduction by enlarge the detector size.