Development of High Efficiency High Resolution Cryogenic Detector for X-ray Fluorescence Applications and Student Training

在材料科学和生物物理学的现代同步加速器荧光实验中，x射线检测往往是限制因素。在过去的20年里，同步加速器辐射源的亮度增加了近10个数量级，但我们收集和辨别发射的x射线的能力却没有跟上。该奖项由材料研究仪器项目授予加州大学戴维斯分校，将支持新型探测器的开发，这将大大提高材料科学和生物物理学中薄膜或稀释样品荧光分析现有仪器的灵敏度。该仪器的开发将使现有的低温探测器适应同步加速器实验的具体需要。将研究和解决目前限制某些发射线灵敏度的光谱伪影的来源。通过添加高Z材料的厚吸收膜，现有探测器的可用能量范围将扩展到1千电子伏特以上。该传感器的总面积和计数率能力将通过增加来增加。该开发将由研究生和博士后研究员与劳伦斯利弗莫尔的高级探测器小组合作完成。低温光谱仪将在提案的基础上提供给合作者。将这种高灵敏度的高分辨率探测器与第三代同步加速器的波动辐射强度相结合，将为以前不可行的科学开辟一系列新的实验方法。研究生将着重于两组实验。他们将开发角度分辨软x射线荧光光谱法，用于薄膜样品的非破坏性深度分析。他们还将把荧光检测的l边吸收光谱扩展到含钒和含锰的金属酶，以确定催化循环过程中金属位点的化学氧化状态。长期目标是将非破坏性深度剖面和样品的原位化学表征与百万分之一级灵敏度相结合。在材料科学和生物物理学的现代同步加速器荧光实验中，x射线检测往往是限制因素。在过去的20年里，同步加速器辐射源的亮度增加了近10个数量级，但我们收集和辨别发射的x射线的能力却没有跟上。该奖项由材料研究仪器项目授予加州大学戴维斯分校，将支持新型探测器的开发，这将大大提高材料科学和生物物理学中薄膜或稀释样品荧光分析现有仪器的灵敏度。该仪器的开发将使现有的低温探测器适应同步加速器实验的具体需要。该开发将由研究生和博士后研究员与劳伦斯利弗莫尔的高级探测器小组合作完成。低温光谱仪将在提案的基础上提供给合作者。将这种高灵敏度的高分辨率探测器与第三代同步加速器的波动辐射强度相结合，将为以前不可行的科学开辟一系列新的实验方法。研究生将着重于两组实验。长期目标是将非破坏性深度剖面和样品的原位化学表征与百万分之一级灵敏度相结合。

X-ray detection is often the limiting factor in modern synchrotron-based fluorescence experiments in material science and biophysics. The brightness available from synchrotron radiation sources has increased by nearly 10 orders of magnitude in the past 20 years, but our ability to collect and discriminate emitted x-rays has not kept pace. This award from the Instrumentation for Materials Research program to the University of California Davis will support new detector development which will greatly enhance the sensitivity of existing instrumentation for fluorescence analysis of thin films or dilute samples in material science and biophysics. This instrument development will adapt existing cryogenic detectors to the specific needs of synchrotron experiments. The origin of the spectral artifacts that presently limit the sensitivity to certain emission lines will be studied and addressed. The current detector's usable energy range will be extended beyond one kilo electronvolt by adding thick absorber films of high Z materials. The total area and count rate capabilities of the sensor will be increased by increasing This development will be done by graduate students and postdoctoral fellows in collaboration with the Advanced Detector Group at Lawrence Livermore. The cryogenic spectrometer will be available to collaborators on a proposal basis. Combining such high-sensitivity high-resolution detectors with the intensity of undulator radiation of third generation synchrotrons will open up a range of new experimental methods for previously unfeasible science. Graduate students will focus on two sets of experiments. They will develop angle-resolved soft x-ray fluorescence spectroscopy for non-destructive depth profiling of thin film samples. They will also extend fluorescence-detected L-edge absorption spectroscopy to vanadium and manganese-containing metalloenzymes to determine the chemical oxidation state of the metal site during the catalytic cycle. The long-term goal is to combine non-destructive depth profiling and in-situ chemical characterization of samples with part per million level sensitivity.X-ray detection is often the limiting factor in modern synchrotron-based fluorescence experiments in material science and biophysics. The brightness available from synchrotron radiation sources has increased by nearly 10 orders of magnitude in the past 20 years, but our ability to collect and discriminate emitted x-rays has not kept pace. This award from the Instrumentation for Materials Research program to the University of California Davis will support new detector development which will greatly enhance the sensitivity of existing instrumentation for fluorescence analysis of thin films or dilute samples in material science and biophysics. This instrument development will adapt existing cryogenic detectors to the specific needs of synchrotron experiments. The development will be done by graduate students and postdoctoral fellows in collaboration with the Advanced Detector Group at Lawrence Livermore. The cryogenic spectrometer will be available to collaborators on a proposal basis. Combining such high-sensitivity high-resolution detectors with the intensity of undulator radiation of third generation synchrotrons will open up a range of new experimental methods for previously unfeasible science. Graduate students will focus on two sets of experiments. The long-term goal is to combine non-destructive depth profiling and in-situ chemical characterization of samples with part per million level sensitivity.