CAPILLARY-OPTICS DEVELOPMENT FOR HIGH FLUX X-RAY MAPPING & SPECTROSCOPY

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目及 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 使用12 keV和9 keV的预聚焦X射线束照射单次反弹毛细管（SBC）以产生高通量X射线微束。使用矢状聚焦双晶体单色仪和双压电晶片反射镜（195 <$m x 125 <$m，分别为水平和垂直FWHM）对1.18 <$1013 ph/s的BioCAT波荡器X射线束进行预聚焦。毛细管入口与预聚焦光束焦点对准，因此整个波荡器光束照射毛细管壁。测试了两种对准配置：a）毛细管中心与预聚焦光束对准（在线），以及B）毛细管一侧与光束对准（离线）。后者在传递的通量和较小的光斑尺寸（在两个方向上d 10微米FWHM）方面更好。测得的输送通量为3.3 <$1012 ph/s。光子通量密度为4.2 <$1010 ph/s/um 2。该实验中使用的光束线主光学器件与大工作距离（约20 mm）毛细管的组合，使其适用于许多需要微米尺寸X射线束和高通量密度的微探针荧光应用。这些特征对于生物样品非常方便，其中典型的金属浓度在几ng/cm 2的范围内。微型XANES实验也是可行的，使用这种组合的光学装置。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. A pre-focused x-ray beam at 12 keV and 9 keV was used to illuminate a single-bounce capillary (SBC) to generate a high flux x-ray microbeam. The BioCAT undulator x-ray beam of 1.18¿1013 ph/s was pre-focused using a sagittal focusing double crystal monochomator and a bimorph mirror (195 ¿m x 125 ¿m, FWHM horizontal and vertical respectively). The capillary entrance was aligned with the pre-focused beam focal point, thus the full undulator beam was illuminating the capillary walls. Two alignment configurations were tested: a) the center of the capillary aligned with the pre-focused beam (in line) and b) one side of the capillary aligned with the beam (off line). The latter being the better in terms of flux delivered and smaller spot size (d 10 microns FWHM in both directions). A 3.3¿1012 ph/s delivered flux was measured. The photon flux density was 4.2¿1010 ph/s/um2. The combination of the beamline main optics with a large working distance (approximately 20 mm) capillary used in this experiment, make it suitable for many microprobe fluorescence applications that require micron size x-ray beam and high flux density. These features are extremely convenient for biological samples, where typical metal concentrations are in the range of a few ng/cm2. Micro-XANES experiments are also feasible using this combined optical arrangement.