DEVELOPMENT OF HGI2 ARRAYS FOR SYNCHROTRON RADIATION

该计划的长期目标是开发新技术， 制造先进的能量色散X射线探测器的大型阵列， 生物医学研究在同步辐射（SR）研究设施。 单个HgI-2阵列元件的能量分辨率达到250-300 eV，速率超过50，000 cps/元件，完成100 元素数组的计数将超过5xl 0 -6 cps，但每个成本约为1000美元。 元素 预计计数率能力和固体 角收集效率将允许在超低稀释度下进行研究 (or作为时间、温度或浓度的函数）， 否则是不可行的或不可能的。 与摆动器和波动器一起使用 在现有和下一代SR源上，这些阵列将 增强我们获得直接结构、键合和 成分信息，已被发现是如此重要， 解开蛋白质和酶功能的机制， 分子水平。 虽然该项目使用HgI-2探测器元件， 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 Si或Ge能量色散探测器。 该探测器开发计划有四个具体目标。 一、（年 1)完成100元素硬x射线探测器系统的建造 目前正在进行中。 其HgI-2像素阵列和所有开发和 生产工程已完成。 剩下的就是制造100个 通道的混合电子和安装系统的一般 在斯坦福大学同步加速器上的XAS测量 实验室（SSRL）。 第二，（2-3年级）设计改进的探测器设计 和电子处理技术，以扩展阵列探测器的优势， 软X射线的范围在500和3000 eV之间。 实现这一目标将 需要重新设计主要系统组件，以减少电子 噪声从250 eV的电流值降低到125 eV或更好。 这将是 通过提高HgI-2晶体质量， 探测器模块设计;通过开发新的FET来降低噪声 结构和实现一种新的、小信号、快速复位方案; 开发新的时变放大器以适应新的复位 方案;重新审查拒绝堆积的原则;并取代 SCA与杂交MCA一起记录整个光谱。 也很高 将开发快速反卷积程序，以科普光谱 峰重叠，即使在125 eV分辨率下仍会发生。 三 (Year 4）使用这些构建100元件软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 路径，并寻求额外的资金，为硬x射线探测器艾米， 特别关注于提高其吞吐量。

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.