抛物面型X射线组合折射透镜聚焦性能的理论与实验研究

结合衍射理论和矩阵光学方法得出抛物面型X射线组合折射透镜的光学性能指标(包括其焦距的严格表达式、薄透镜近似的判定准则、透过率和有效孔径,以及极限聚焦光斑尺寸等).采用X射线深度光刻技术实际制作了PMMA材料抛物面型X射线组合折射透镜并给出了工艺测试结果.最后在北京同步辐射装置(BSRF)上,实际构建了基于3种不同结构参数的PMMA材料抛物面型X射线组合折射透镜的微束聚焦实验系统.并实际测试了其聚焦性能,均获得了良好的聚焦效果,给出实测结果并对实测结果进行了分析和讨论.     

制作工艺误差对X射线组合折射透镜聚焦性能影响研究

本文主要介绍对X射线组合折射透镜的制作工艺误差对其聚焦性能影响的研究结果. 首先给出采用深度X射线光刻技术制作的PMMA材料圆柱面型X组合折射透镜的工艺测试结果,得出制作工艺误差值,定性分析制作工艺误差对X射线组合折射透镜聚焦性能的影响. 然后根据实际的制作工艺误差建模,给出详尽的理论分析和定量的理论模拟结果. 最后在北京同步辐射装置(BSRF)上,构建基于PMMA材料的圆柱面型X射线组合折射透镜的微束聚焦实验系统,实际测试了有明显工艺误差和尽量消除工艺误差的两种X射线组合折射透镜的聚焦性能,给出实测结果 关键词： X射线组合折射透镜 制作工艺误差 X射线聚焦性能 同步辐射     

铜材料X射线聚焦组合透镜的设计与制作

铜材料X射线聚焦组合透镜是一种基于折射效应的X射线聚焦元件。简单介绍了组合透镜的设计理论研究结果,并据此对材料作了选择。针对铜材料组合透镜,分析了组合透镜结构参数、X射线工作波长的选择对组合透镜光学性能的影响。在此基础上,设计了组合透镜的结构参数,使其在硬X射线波段具有较好的聚焦性能,并能获得较高的焦斑强度。采用准LIGA技术制作了铜材料X射线组合透镜,给出了部分铜材料X射线组合透镜结构测量结果。     

高能X射线组合透镜聚焦性能的实验结果

高能X射线组合透镜是一种基于折射效应的新型X射线光学元件。报道了这种新型X射线光学元件聚焦性能的最新实验结果。设计的高能X射线组合透镜为聚甲基丙烯酸甲酯(PMMA)材料,包括40个相同的、顺序排布的平凹折射单元,折射单元的球面半径为200μm,组合透镜的几何口径约为500μm,长度约为8 mm,焦距约为1.3 m。简要描述了PMMA材料X射线组合透镜的制作技术和制作过程。并给出了X射线组合透镜聚焦性能测试实验系统和实验条件。最后给出8 keV单色X射线辐射下,PMMA材料X射线组合透镜的聚焦性能的测试结果,对实际测试结果进行了分析和讨论,得出结论,焦距等参量与理论计算结果基本吻合。     

背面曝光技术制作沙漏状X射线组合折射透镜

在分析沙漏状X射线组合折射透镜（X-ray compound refractive lens,XCRL）的折射聚焦理论的基础上,设计并利用背面曝光技术制作了SU-8材料的沙漏状XCRL,该技术在保证图形准确性的同时减少了工艺步骤,使制作更加简便易行.在10?keV单色X射线辐射下,对制作的透镜进行了聚焦性能的实验测试,结果表明,所制作的透镜较好地实现了一维聚焦. 关键词： 组合折射透镜 背面曝光 沙漏状 SU-8     

高能X射线聚焦组合透镜的理论研究

X射线聚焦组合透镜是一种利用折射效应对X射线辐射聚焦的新型元件。针对X射线波段的特性,综合考虑折射和吸收效应得出组合透镜的衍射屏函数,并利用衍射理论推导出X射线组合透镜的设计理论。利用统计学理论中一阶、二阶原点矩表征像面处的光学性能,使设计更简洁。该理论方法可方便地推广到双凹折射单元情况。通过数值计算分析了像向处强度分布的二阶中心矩以及焦点处辐射强度随组合透镜结构参最的变化关系,给出了一种铝基X射线组合透镜的结构参量设计结果。对于设计的组合透镜结构参量,计算了当X射线辐射能量分别为0．93 keV．9．89 keV和29．78 keV时,X射线辐射经过组合透镜后的焦点强度分布。     

复合折射透镜的进展和应用

文章介绍了X射线复合折射透镜的工作原理,详细回顾了X射线复合折射透镜的发展历程,综述了近年来X射线复合折射透镜的研究成果及其主要应用领域.     

一种用于软X射线激光去相干的单玻璃管光学透镜设计

激光具有亮度高、单色性好、高相干性及方向性好的优势,然而在激光成像、激光加工等场景只想利用其高亮度或高单色性,高相干性导致的干涉效应会影响和限制其应用效果.通过模拟计算的方法,设计了一种针对软X射线激光去相干的新型单玻璃管光学透镜.模拟结果显示,针对波长为10 nm、束腰半径为1.25 mm的软X射线激光光束,透镜入口端内直径5 mm、出口端内直径0.6 mm、长度15 cm的单玻璃管光学透镜在有效降低软X射线激光光束相干度的同时,在出口处获得了发散度为30—50 mrad的出射光束,相应的传输效率为78%,光强增益为52.74.针对波长不低于1 nm的激光光束,该型号的单玻璃管光学透镜能够将光束的传输效率保持在30%以上.本文还探讨了入射光能量和透镜长度对器件传输结果的影响.结果表明,根据全反射原理设计的单玻璃管光学透镜能够满足极紫外到X射线波长范围内激光去相干的应用需求,在X射线激光成像、激光加工等方面具有广泛的应用前景.     

金刚石复合折射透镜的设计及加工初探

复合折射透镜（compound refractive lens, CRL）因具有结构紧凑、焦距可调、准直方便等优点,被用作硬X射线自由电子激光（X-ray free electron laser, XFEL）装置的光束聚焦器件。面向XFEL光束高精度聚焦对高性能CRL的实际需求,从CRL的几何结构设计原理出发,分析了不同材料CRL的性能参数,证明了单晶金刚石材料是适用于XFEL光束聚焦的CRL优选材料。同时,考虑超硬金刚石材料的难加工特性以及低重频钛宝石飞秒激光不能实现大厚度材料高效加工的实际问题,探索了高重频光纤飞秒激光对大厚度单晶金刚石材料进行高效加工的可行性。研究结果表明,高重频飞秒激光精密加工技术是实现金刚石CRL制备的有效手段。     

整体X光透镜及其在X射线衍射技术中的应用

概述了整体Ｘ光透镜的物理性能及其在Ｘ射线衍射技术中的应用研究，介绍了所研制的新型衍射装置及其测量结果． The basic physical properties and applications in X ray diffraction technology for the monolithic capillary lens are described. The new designed diffraction facility and its measurment results are laso introduced.     

Pink‐beam focusing with a one‐dimensional compound refractive lens

The performance of a cooled Be compound refractive lens (CRL) has been tested at the Advanced Photon Source (APS) to enable vertical focusing of the pink beam and permit the X‐ray beam to spatially overlap with an 80 µm‐high low‐density plasma that simulates astrophysical environments. Focusing the fundamental harmonics of an insertion device white beam increases the APS power density; here, a power density as high as 500 W mm^?2 was calculated. A CRL is chromatic so it does not efficiently focus X‐rays whose energies are above the fundamental. Only the fundamental of the undulator focuses at the experiment. A two‐chopper system reduces the power density on the imaging system and lens by four orders of magnitude, enabling imaging of the focal plane without any X‐ray filter. A method to measure such high power density as well as the performance of the lens in focusing the pink beam is reported.     

Large‐acceptance diamond planar refractive lenses manufactured by laser cutting

For the first time, single‐crystal diamond planar refractive lenses have been fabricated by laser micromachining in 300 µm‐thick diamond plates which were grown by chemical vapour deposition. Linear lenses with apertures up to 1 mm and parabola apex radii up to 500 µm were manufactured and tested at the ESRF ID06 beamline. The large acceptance of these lenses allows them to be used as beam‐conditioning elements. Owing to the unsurpassed thermal properties of single‐crystal diamond, these lenses should be suitable to withstand the extreme flux densities expected at the planned fourth‐generation X‐ray sources.     

Diffractive–refractive optics: low‐aberration Bragg‐case focusing by precise parabolic surfaces

Based on analytical formulae calculations and ray‐tracing simulations a low‐aberration focal spot with a high demagnification ratio was predicted for a diffractive–refractive crystal optics device with parabolic surfaces. Two Si(111) crystals with two precise parabolic‐shaped grooves have been prepared and arranged in a dispersive position (+,?,?,+) with high asymmetry. Experimental testing of the device at beamline BM05 at the ESRF provided a focal spot size of 38.25 µm at a focal distance of 1.4 m for 7.31 keV. This is the first experiment with a parabolic‐shaped groove; all previous experiments were performed with circular grooves which introduced extreme aberration broadening of the focal spot. The calculated and simulated focal size was 10.8 µm at a distance of 1.1 m at 7.31 keV. It is assumed that the difference between the measured and calculated/simulated focal spot size and focal distance is due to insufficient surface quality and to alignment imperfection.     

X‐ray collimation by crystals with precise parabolic holes based on diffractive–refractive optics

Two crystals with precise parabolic holes were used to demonstrate sagittal beam collimation by means of a diffractive–refractive double‐crystal monochromator. A new approach is introduced and beam collimation is demonstrated. Two Si(333) crystals with an asymmetry angle of α = 15° were prepared and arranged in a dispersive position (+,?,?,+). Based on theoretical calculations, this double‐crystal set‐up should provide tunable beam collimation within an energy range of 6.3–18.8 keV (Θ_B = 71–18.4°). An experiment study was performed on BM05 at ESRF. Using 8.97 keV energy, the beam profile at various distances was measured. The experimental results are in good agreement with theoretical predictions. Owing to insufficient harmonic suppression, the collimated (333) beam was overlapped by horizontally diverging (444) and (555) beams.     

Design and fabrication of low-cost X-ray mirrors

Traditional X-ray mirrors made from Zerodur and silicon carbide are quite expensive because of the fabrication cost involved in achieving a very high surface finish of the order of 15 Å or better. The cost of X-ray mirrors can be greatly reduced by using replication methods for producing the grazing-incidence type mirrors. This paper presents the optical and optomechanical design for a Wolter type I mirror and its mount, and the fabrication method used to produce a low-cost replicated nickel mirror. The finite element analysis results for this mirror are also presented. The design and fabrication steps for the aluminium master mandrel used for replication are also discussed. A surface finish of better than 15 Å was achieved for a such an electroformed mirror with a wall thickness of only 1 mm.     

Design and fabrication of one-dimensional focusing X-ray compound lens with Al material

A method based on Fourier spectrum analysis for predicting the performances of the X-ray compound lenses is briefly introduced,the theoretical result obtained is the same as that of Fresnel-Kirchhoff approach.A kind of technique named moulding is developed for fabricating the one-dimensional (1D) compound X-ray lens with Al material and the fabrication process is presented.In addition,a two-time coating method is used to improve the numerical apertures of the compound lenses.Furthermore,the focusing performance of the Al compound X-ray lens under the high energy X-rays is measured.