大面积MCP-PMT K_2CsSb光电阴极理论与测控技术研究

Theory and Control Technology of Large Area MCP-PMT K_2 CsSb Photocathode

针对SBA／UBA光电阴极和中国科学院高能物理研究所380-510nm转换波长的闪烁体，分别从KzCsSb光电阴极第一性原理、结构优化、以及材料生长机理与测控技术等方面进行研究。第一性原理计算结果表明，双碱光电阴极K1.75CsSb1.25是直接禁带半导体，能带弯曲最大，功函数最小；中微子与闪烁体相互作用后发射光子的光谱范围在380-510nm，可以确定双碱阴极透射式工作范围在2．92～3．26eV，反射式工作范围在2．43-2．92eV；针对球形光电倍增管结构，提出了透射式与反射式阴极量子效率最大化方案和K1.75CsSb1.25阴极6点监控制备方法，给出了测试方法。

K2CsSb photocathode were studied from first principle, structure optimization, as well as the material growth mechanism and control technology etc., for SBA/UBA photocathode and scintillator of 380 -510 nm wavelength conversion of High Energy Physics Institute of the Chinese Academy of Sciences The first principle calculation results show that the double alkali photocathode K1.75CsSbl.25 is a direct band gap semiconductor, has maximum band bending and minimum work function. According to the spectral range of emission photon on interact neutrino with scintillator, we can determine the double alkali cathode transmission-mode works in the range of 2.92-3.26 eV, reflecting-mode works in 2.43-2.92 eV. Based on the spherical photomultiplier tube structure, we present scheme of maximizing quantum efficiency of the transmission and reflection cathode and K1.75CsSbl.25 cathode 6 points monitoring preparation method. And the testing method is given.