MULTILAYER ANALYSER FOR XAFS: X RAY FLUORESCENCE DETECTOR

该项目的目标是开发能量分辨x射线。 使用合成多层膜的荧光探测器。20人组 采用渐变多层膜的多层阵列探测器在 BioCAT的光束线。这些元素相对于彼此对齐 使用微调机制。探测器校准曲线 是通过旋转衍射面中的所有元素而获得的 具有固定的光束入口狭缝。探测器的吞吐量为 大约26%。获得了与探测器类似的吞吐量 当在其他荧光能量下进行校准时，例如，锰、钴、铜和 锌，基本上具有相同的吞吐量。对探测器进行了测试 稀释生物系统。信号与背景的比率为 约为5比1，而在没有 分析器为1到3。因此，总拒绝率约为15 泰晤士报。为了提高分析器检测器的吞吐量，我们有 仔细选择与多层沉积相关的因素，在 详细分析了影响反射率的因素。24个元素 分析器阵列探测器已经设计并正在制造中。 与20个元素的单位类似，总检测立体角为 在MnKA荧光能量下为0.21，在锌KA荧光能量下为0.14。关于测试的 安装了7个元件的单元显示，吞吐量为35%，多 比20个元素的单元更好。这个新的单元将建成并 在半年内进行了运行测试。

The objective of the project is to develop energy-resolving x-ray fluorescence detectors using synthetic multilayers. A 20-element multilayer array detector using graded multilayers was fully tested at the BioCAT beamline. The elements were aligned relative to each other using the fine adjustment mechanism. The detector calibration curve was obtained by rotating all the elements in the diffraction plane with a fixed beam entrance slits. The throughput of the detector is approximately 26%. Similar throughput of the detector was obtained when calibrated at other fluorescence energies, such as Mn, Co, Cu and Zn, with essentially the same throughput. The detector was tested on dilute biological systems. The signal to background ratio is approximately 5 to 1, while the signal to background ratio without the analyzer is 1 to 3. Thus the total rejection rate is approximately 15 times. To improve the throughput of the analyzer detector, we have carefully chosen the factors relative to multilayer deposition, in particular the factors affecting the reflectivity. A 24-element analyzer array detector has been design and are being fabricated. Similar to the 20-element unit, the total detection solid angle is 0.21 at Mn Ka and 0.14 at Zn Ka fluorescence energies. Tests on the unit with 7-elements installed show that the throughput is 35%, much better than the 20-element unit. This new unit will be completed and tested for operation within half year.