用空心阴极光源标定极紫外-软X射线单色仪

为了使单色仪在极紫外-软X射线波段准确地进行波长扫描,需要对单色仪进行波长标定。单色仪的所有组件都放置在罗兰圆的圆周上,改变出射狭缝在罗兰圆上的位置,在单色仪的出射狭缝处就可以得到相应波长的单色光。通过测量标准He空心阴极光源的发射光谱,对Mcpherson247单色仪进行波长标定,并对实验结果进行了分析,得出在1~100nm波段内单色仪标定精度为±0.017nm~±0.097nm。     

An alternative scheme of angular‐dispersion analyzers for high‐resolution medium‐energy inelastic X‐ray scattering

The development of medium‐energy inelastic X‐ray scattering optics with meV and sub‐meV resolution has attracted considerable efforts in recent years. Meanwhile, there are also concerns or debates about the fundamental and feasibility of the involved schemes. Here the central optical component, the back‐reflection angular‐dispersion monochromator or analyzer, is analyzed. The results show that the multiple‐beam diffraction effect together with transmission‐induced absorption can noticeably reduce the diffraction efficiency, although it may not be a fatal threat. In order to improve the efficiency, a simple four‐bounce analyzer is proposed that completely avoids these two adverse effects. The new scheme is illustrated to be a feasible alternative approach for developing meV‐ to sub‐meV‐resolution inelastic X‐ray scattering spectroscopy.     

使用光栅单色仪测量红宝石晶体的吸收和发射光谱

使用WDS-8型光栅单色仪测量了室温下红宝石晶体的吸收光谱和发射光谱.通过该实验,学生在了解光致发光原理及光致发光材料光谱特性的同时,掌握单色仪的使用方法和技巧.     

The LUCIA beamline at SOLEIL

Commissioned in May 2004 on the SLS machine, the LUCIA beamline was moved to the synchrotron SOLEIL during the summer of 2008. To take advantage of this new setting several changes to its design were introduced. Here, a review of the various improvements of the mechanics and, mostly, of the optics is given. Described in detail are the results of a new multilayer grating monochromator implemented on the Kohzu vessel already holding the two‐crystal set‐up. It consists of a grating grooved onto a multilayer (replacing the first crystal) associated to a multilayer (as a second crystal). It allows a shift of the low‐energy limit of the beamline to around 500 eV with an energy resolution and a photon flux comparable with those of the previous couples of crystals (KTP and beryl).     

Sapphire hard X‐ray Fabry–Perot resonators for synchrotron experiments

Hard X‐ray Fabry–Perot resonators (FPRs) made from sapphire crystals were constructed and characterized. The FPRs consisted of two crystal plates, part of a monolithic crystal structure of Al₂O₃, acting as a pair of mirrors, for the backward reflection (0 0 0 30) of hard X‐rays at 14.3147 keV. The dimensional accuracy during manufacturing and the defect density in the crystal in relation to the resonance efficiency of sapphire FPRs were analyzed from a theoretical standpoint based on X‐ray cavity resonance and measurements using scanning electron microscopic and X‐ray topographic techniques for crystal defects. Well defined resonance spectra of sapphire FPRs were successfully obtained, and were comparable with the theoretical predictions.     

Large‐surface‐area diamond (111) crystal plates for applications in high‐heat‐load wavefront‐preserving X‐ray crystal optics

Fabrication and results of high‐resolution X‐ray topography characterization of diamond single‐crystal plates with large surface area (10 mm × 10 mm) and (111) crystal surface orientation for applications in high‐heat‐load X‐ray crystal optics are reported. The plates were fabricated by laser‐cutting of the (111) facets of diamond crystals grown using high‐pressure high‐temperature methods. The intrinsic crystal quality of a selected 3 mm × 7 mm crystal region of one of the studied samples was found to be suitable for applications in wavefront‐preserving high‐heat‐load crystal optics. Wavefront characterization was performed using sequential X‐ray diffraction topography in the pseudo plane wave configuration and data analysis using rocking‐curve topography. The variations of the rocking‐curve width and peak position measured with a spatial resolution of 13 µm × 13 µm over the selected region were found to be less than 1 µrad.     

The Double Monochromator Geometric Theory and Compensation of Aberrations

The light path function for the double monochromator is constructed, and the formulas of account of the members of its expanding in ascending power series adequate for the defocusing and the first order astigmatism aberrations are found. On the basis of results of the minimisation of obtained expressions the opportunity of construction of a double monochromator so that the second monochromator fractionally compensates aberrations of the first one is analysed. It is also noticed, that in the scheme of the double monochromator under certain conditions compensation of an astigmatism of the second order is automatically carried out. It allows to use a deviation angle of the scheme for more complete compensation of other aberrations and to develop double monochromators with the improved performances.This paper was originally presented at the 2nd International Conference on Optical Design and Fabrication, ODF2000 which was held on November 15-17, 2000 at the International Conference Center, Tokyo, Waseda University, Japan.