The X-ray diffraction beamline developed at Shanghai Synchrotron Radiation Facility(SSRF)is located at the BL14B1 bending magnet port of the 3.5 Ge V storage ring. The beamline optics is based on a collimating mirror,a sagittally focused double crystal monochromator and a focusing mirror. Photon flux of 4.43 × 1011phs/s at10 ke V is obtained. The primary instrument equipped in the experimental end-station is a Huber 5021 sixcycle diffractometer. BL14B1 is a general purpose X-ray diffraction beamline and focused on material science,condensed matter physics and other relevant fields looking for structural information.
本文制备了平均直径为1.4 nm的11-巯基十一烷酸(Mercaptoundecanoic acid,MUA)修饰的金纳米颗粒,随后通过硅晶片上壳聚糖薄涂层静电吸附制备了厚度约为10 nm的超薄膜,原子力显微镜(Atomic Force Microscopy,AFM)和扫描电子显微镜(Scanning Electron Microscopy,SEM)表明金纳米颗粒在薄膜中分布较为均匀且薄膜较平整。进一步采用紫外光电子能谱(Ultraviolet Photoelectron Spectroscopy,UPS)研究了不同热处理温度对超薄膜的二次电子发射能力的影响。结果表明,适度的热处理有助于超薄膜二次电子发射强度的提高,尤其是经150°C热处理的薄膜二次电子发射峰强是未处理样品的4倍,更高的热处理温度造成二次电子发射峰强度急剧下降。本文结果有助于推动有机配体金纳米颗粒超薄膜在光电子发射材料方面的应用。
A design for an efficient monochromatic electron source for Inverse Photoemission Spectroscopy （IPES） apparatus is described. The electron source consists of a BaO cathode, a focus electrostatic lens, a hemispherical deflection monochromator （HDM）, and a transfer electrostatic lens. The HDM adopts a “slit-in and slit-out” structure and the degradation of first-order focusing is corrected by two electrodes between the two hemispheres, which has been investigated by both analytical methods and electron-ray tracing simulations using the SIMION program. Through the focus lens, the HDM, and the standard five-element transfer lens, an optimal energy resolution is estimated to be about 53 MeV with a beam flux of 27 μA. Pass energy （P.E.） of 10 eV and 5 eV are discussed, respectively.
