Institute of Materials Structure Science, KEK, 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan.
J Synchrotron Radiat. 2012 Sep;19(Pt 5):722-7. doi: 10.1107/S0909049512024971. Epub 2012 Jul 7.
Carbon contamination of optics is a serious issue in all soft X-ray beamlines because it decreases the quality of experimental data, such as near-edge X-ray absorption fine structure, resonant photoemission and resonant soft X-ray emission spectra in the carbon K-edge region. Here an in situ method involving the use of oxygen activated by zeroth-order synchrotron radiation was used to clean the optics in a vacuum ultraviolet and soft X-ray undulator beamline, BL-13A at the Photon Factory in Tsukuba, Japan. The carbon contamination of the optics was removed by exposing them to oxygen at a pressure of 10(-1)-10(-4) Pa for 17-20 h and simultaneously irradiating them with zeroth-order synchrotron radiation. After the cleaning, the decrease in the photon intensity in the carbon K-edge region reduced to 2-5%. The base pressure of the beamline recovered to 10(-7)-10(-8) Pa in one day without baking. The beamline can be used without additional commissioning.
光学碳污染是所有软 X 射线光束线中的一个严重问题，因为它会降低实验数据的质量，例如在碳 K 边缘区域的近边 X 射线吸收精细结构、共振光发射和共振软 X 射线发射谱。在这里，我们使用了一种原位方法，涉及使用零级同步辐射激活的氧气来清洁日本筑波市光子工厂的 BL-13A 真空紫外和软 X 射线波荡器光束线中的光学器件。通过将光学器件暴露在 10(-1)-10(-4)Pa 的氧气中 17-20 小时，并同时用零级同步辐射照射它们，去除了光学器件上的碳污染。在清洁之后，碳 K 边缘区域的光子强度下降到 2-5%。在一天内，无需烘烤，光束线的基底压力恢复到 10(-7)-10(-8)Pa。光束线可以无需额外调试即可使用。
