High Efficiency X-ray Fluorescence Detectors

高效 X 射线荧光探测器

• 批准号: 7480504
• 负责人: ke zhang
• 金额: $ 37.99万
• 依托单位: HD TECHNOLOGIES, INC.
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-20 至 2010-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7480504
• 关键词: Adopted; Area; Biology; Collaborations; Collection; Communities; Count; Deposition; Detection; Development; Educational workshop; Elements; Fluorescence; Fluorescence Spectroscopy; Generations; Investigation; KLK3 gene; Marketing; Measurement; Motor; Operative Surgical Procedures; Performance; Phase; Photons; Rate; Reporting; Research; Resolution; Rest; Roentgen Rays; Scanning; Solid; Source; Synchrotrons; System; Technology; Testing; Time; Work; base; beamline; design; detector; improved; new technology; next generation; simulation

DESCRIPTION (provided by applicant): It has been repeatedly emphasized in various reports and workshops [1-2] that the development of better X- ray fluorescence detector systems is urgently needed to solve the saturation problems with the currently available detectors. The multilayer analyzer array detector (MAAD) using linearly graded multilayers has been successfully developed to handle the large photon flux from the third generation synchrotron sources. However, this type of detectors has limited detection solid angle restricted by its vertical and horizontal acceptance. The detectors will suffer largely degraded energy resolution and loss of throughput if horizontal acceptance angle is increased. In the Phase I proposal, we have proposed to develop multilayer array analyzer detectors using radially graded multilayers. By largely increasing the horizontal acceptance per multilayer, this new design provides a 2.5 times of collection solid angle increase. Furthermore, the new design substantially reduces the energy resolution and improves the throughput of the analyzers due to the preferred gradient design and optimized deposition material selection. Thus we have demonstrated 6-8 times of combined improvement of performance over the previous analyzer detector design. In a subsequent investigation after the completion of our Phase II project (RR015994), we have demonstrated that large background rejection, in excess of 10,000, can be achieved with a dual multilayer analyzer in }plus} configuration, rather than }minus} configuration that we have proposed previously. Thus we will combine the two technologies, namely the radially graded multilayer technology and the new dual multilayer analyzer configuration to fabricate very desirable fluorescence analyzer detectors to benefit the user community. In the Phase II project, we will design, fabricate and test one radially graded multilayer array analyzer detector (RMAAD) optimized for energies from 1.2 to 4 KeV, and one dual multilayer array analyzer detector (DMAAD) in the plus configuration optimized from 3.5 to 10 KeV. We will adopt a modular design for the RMAAD unit, where smaller unit containing 5 miltilayers can be added to form a full-scale unit. The DMAAD unit can work as a RMAAD when large background rejection is not required. The proposed DMAAD will allow for the elemental detection in ppb levels or in Physiologically relevant concentrations. In addition to the improved detection efficiency, the proposed analyzer detectors extend the current fluorescence detection capability in two crucial areas: very dilute system regime and intermediate to lower energy regions, which are most relevant to biology. The market of the new detectors will no longer be restricted to synchrotron beamlines with intense flux, but all the beamlines which are involved in spectroscopy and fluorescence analysis. The advances made in this proposal will enhance the capability of research for x-ray spectroscopy and fluorescence analysis under high count rate achievable at the current and next generation synchrotron sources.

说明(申请人提供)：在各种报告和研讨会[1-2]中一再强调，迫切需要开发更好的X射线荧光探测器系统，以解决现有探测器的饱和问题。采用线性梯度多层膜的多层分析器阵列探测器(MAAD)已成功地用于处理来自第三代同步加速器源的大光子通量。然而，这类探测器的探测立体角有限，受其垂直和水平接受能力的限制。如果水平接受角增加，探测器的能量分辨率将大大降低，吞吐量也会损失。在第一阶段的方案中，我们已经提出了利用径向梯度多层膜来开发多层阵列分析器探测器。通过大幅增加每多层的水平接受度，这种新设计提供了2.5倍的收集立体角增加。此外，由于优选的梯度设计和优化的沉积材料选择，新设计大大降低了能量分辨率并提高了分析仪的吞吐量。因此，我们已经展示了与以前的分析仪检测器设计相比，性能总共提高了6-8倍。在我们的第二阶段项目(RR015994)完成后的后续调查中，我们已经证明了使用双多层分析仪在加配置下可以实现超过10,000的大背景抑制，而不是我们之前提出的减配置。因此，我们将结合这两项技术，即径向梯度多层技术和新的双多层分析器配置，以制造非常理想的荧光分析器探测器，以造福于用户社区。在第二阶段项目中，我们将设计、制造和测试一个径向梯度多层阵列分析器探测器(RMAAD)，能量优化为1.2至4keV，以及一个双多层阵列分析器探测器(DMAAD)，其PLUS配置优化为3.5至10keV。我们将对RMAAD单元采用模块化设计，可以添加包含5个多层的较小单元，形成一个完整的单元。当不需要大的背景抑制时，DMAAD单元可以作为RMAAD工作。拟议的DMAAD将允许以ppb水平或生理相关浓度进行元素检测。除了提高检测效率外，所提出的分析器检测器还将当前的荧光检测能力扩展到两个关键区域：与生物学最相关的非常稀薄的体系区域和中低能区。新探测器的市场将不再局限于强通量的同步加速器光束线，而是涉及光谱分析和荧光分析的所有光束线。这项提议所取得的进展将加强在当前和下一代同步加速器源可实现的高计数率下的X射线光谱分析和荧光分析的研究能力。