Silicon Detectors for Synchrotron X-Ray Fluorescence

描述(由申请人提供)： 我们将开发一种新型的高效硅X射线探测器，具有良好的能量分辨率和高计数率能力，用于同步辐射X射线荧光(XRF)应用。我们建议将目前在0.3 mm厚的薄衬底上制造的非常成功的硅漂移探测器设计扩展到厚探测器(厚达1.5 mm)领域。这一增加的厚度对于将探测器的X射线吸收能力扩展到40keV至关重要。目前0.3 mm厚的硅在10keV以上的效率迅速下降(在30keV时降至9%)，而1.5 mm厚的硅在30keV时效率为42%。同步辐射XRF技术正在成为生物医学应用领域中必不可少的工具。一些同步加速器--如斯坦福同步辐射实验室和国家同步加速器光源--拥有专门用于XRF分析的硬X射线光束线。第三代同步加速器，如先进光子源(APS)，具有6-40keV范围内的光子通量亮度，使探测器尺寸在微米及以下的情况下能够进行高效的X射线荧光分析。所有这些光束线都需要高计数率、高能量分辨率、能量色散的X射线探测器，其有效吸收高达40keV。与传统的硅和锗XRF探测器相比，新的、更厚的漂移探测器将具有非低温冷却、良好的能量分辨率和数量级的计数速率改进的优势，同时提供10keV以上的效率显著提高。 第一阶段的工作将包括厚硅漂移探测器的设计和制造，以及探测器对5-60keV范围内X射线的噪声、能量分辨率、效率和计数率能力的表征。第二阶段的工作将包括开发厚漂移探测器阵列和相关的低噪声读出电子设备，用于建造XRF光谱仪，该光谱仪将在阿贡国家实验室APS的同步加速器XRF实验中进行评估。

DESCRIPTION (provided by applicant): We will develop a new high efficiency silicon x-ray detector, with good energy resolution and high count rate capability for synchrotron x-ray fluorescence (XRF) applications. We propose to extend the very successful silicon drift detector design, currently fabricated on thin 0.3 mm thick substrates, into the realm of thick detectors (up to 1.5 mm thick). This added thickness is critical in extending the x-ray absorption capability of the detectors up to 40 keV. The current 0.3 mm thick silicon rapidly falls off in efficiency above 10 keV (down to 9% at 30 keV), whereas 1.5 mm is 42 % efficient at 30 keV. Synchrotron XRF techniques are becoming essential tools in the field of bio-medical applications. Several synchrotrons - such as the Stanford Synchrotron Radiation Laboratory and the National Synchrotron Light Source - have hard x-ray beam lines that are dedicated to XRF analysis. Third generation synchrotrons, such as the Advanced Photon Source (APS), have photon flux brilliances in the 6-40 keV region that allow efficient x-ray fluorescence analysis with probe sizes of a micrometer and below. All of these beamlines require high count rate, good energy resolution energy dispersive x-ray detectors that have efficient absorption up to 40 keV. The new, thicker drift detectors will have the advantages of non-cryogenic cooling, good energy resolution, and an order of magnitude improvement in count rates compared with conventional silicon and germanium XRF detectors, while providing a significant increase in efficiency above 10 keV. The Phase I work will include the design and fabrication of the thick silicon drift detectors, and the characterization of the detectors with respect to noise, energy resolution, efficiency and count rate capability in response to x-rays in the 5-60 keV range. The Phase II work will include development of a thick drift detector array, and the associated low noise readout electronics, for the construction of an XRF spectrometer that will be evaluated in a synchrotron XRF experiment at the APS at Argonne National Laboratory.