DEVELOPMENT OF HGI2 ARRAYS FOR SYNCHROTRON RADIATION

该计划的长期目标是开发新技术，以 制造先进的能量色散x射线探测器的大型阵列 在同步辐射(SR)研究设施进行生物医学研究。 单个HGI-2阵列单元达到250-300的能量分辨率 EV在6keV，速率超过50000 cps/元素，完成100 元素数组将超过5x10-6cps，但每个元素数组的成本约为1000美元 元素。计数能力和固体率方面的预期增长 角度收集效率将允许在超低稀释条件下进行研究 (或作为时间、温度或浓度的函数) 否则是不可行的或不可能的。与摇摆器和波浪器连用 在现有和新一代SR源上，这些阵列将 增强我们的能力，获得直接的结构，结合和 成分信息已被发现是如此重要的 解开蛋白质和酶的作用机制 分子水平。虽然本项目使用HGI-2探测器元件，因为 由于其接近室温的操作和易于钝化， 低成本的混合信号处理电子设备与 硅或锗能量色散探测器。 这项探测器开发计划有四个具体目标。第一，(年 1)完成100元硬X射线探测器系统的建设 目前正在进行中。其HGI-2像素阵列和所有显影和 生产工程齐全。剩下的就是捏造100 混合电子渠道和安装系统一般为 斯坦福同步辐射的用户群体XAS测量 实验室(SSRL)。第二，(2-3年级)设计改进的探测器设计 以及电子处理技术，以将阵列探测器的优点扩展到 软X射线的范围在500到3000 eV之间。实现这一目标将 要求对主要系统组件进行重新设计，以减少电子设备 噪声从当前的250 eV降至125 eV或更好。这将是 实现方式：提高HGI-2晶体质量；精炼前端 探测器模块设计；通过开发新的FET降低前置放大器噪声 构造并实施一种新的、小信号、迅速的重置方案； 开发一种新的时变放大器以适应新的重置 方案；重新检查堆积拒绝的原则；并替换 SCA与杂化的MCAS一起记录整个光谱。也是一个很高的 将开发快速去卷积程序来处理光谱 峰重叠，即使在125 eV分辨率下也会发生。第三 (第4年)使用这些材料建造一个100元软X射线探测器阵列 技术，并将其用于支持现有的NIH生物技术 在SSRL或其他地方的研究计划。第四，制定升级方案 路径，并寻求额外的资金，为硬X射线探测器艾米， 特别注重提高其吞吐量。

This program's long term objective is to develop new technologies for creating large arrays of advanced, energy dispersive x-ray detectors for biomedical research at Synchrotron Radiation (SR) research facilities. With single HgI-2 array elements attaining energy resolutions of 250-300 eV at 6 keV, at rates exceeding 50,000 cps/element, a completed 100 element array would count at over 5xl0-6 cps, yet cost about $1000 per element. The projected increases in count rate capability and solid angle collection efficiency will allow research at ultra-low dilutions (or as a function of time, temperature, or concentration) that would otherwise be infeasible or impossible. Used with wigglers and undulators on both existing and next generation SR sources, these arrays will enhance our ability to obtain the direct structural, bonding and compositional information which has been found to be so important in unravelling the mechanisms of protein and enzyme function at the molecular level. While this project uses HgI-2 detector elements because of its near room temperature operation and ease of passivation, the low-cost, hybridized signal processing electronics work equally well with Si or Ge energy dispersive detectors. This detector development program has four specific goals. First, (Year 1) complete construction of the 100 element hard x-ray detector system currently in progress. Its HgI-2 pixel array and all developmental and production engineering are complete. What remains is to fabricate 100 channels of hybridized electronics and install the system for general user community XAS measurements at the Stanford Synchrotron Radiation Laboratory (SSRL). Second, (Years 2-3) devise improved detector design and electronic processing techniques to extend array detector benefits to the soft x-ray range between 500 and 3000 eV. Meeting this goal will require re-engineering the major system components to reduce electronic noise to 125 eV or better from the current value of 250 eV. This will be achieved by: improving the HgI-2 crystal quality; refining the front end detector module design; reducing preamplifier noise by developing new FET structures and implementing a new, small signal, prompt reset scheme; developing a new, time variant amplifier to accommodate the new reset scheme; re-examining the principles of pileup rejection; and replacing the SCAs with hybridized MCAs to record entire spectra. Also a high speed deconvolution procedure will be developed to cope with spectral peak overlaps, which will still occur even with 125 eV resolution. Third (Year 4) construct a 100 element soft x-ray detector array using these technologies and deploy it in support of existing NIH biotechnology research programs at SSRL or elsewhere. Fourth, formulate an upgrade path, and seek additional funding, for the hard x-ray detector amy, focusing particularly on improving its throughput.