软X射线晶体标定系统研制

研制了一套完整的软X射线晶体积分反射系数标定系统,包括针对CC224M软X射线源所设计的专用的晶体标定室、晶体与探测器的转动控制机构、复合真空及供气系统、作为标定探测器的流气式正比计数器等。在这一系统上开展了实验研究,获得了TAP晶体对Cu-Lα(13.33)、Al-Kα(8.32)两种入射波长的积分反射系数,验证了系统的有效性。     

软X射线条纹相机的静态性能标定

软X光扫描相机是对软X光时间特性进行研究的主要诊断工具。我们利用同步辐射作为光源，对它的静态性能：能量响应、增益等性能进行了相对标定，给出了软X光条纹相机的能量响应曲线和增益特性曲线，并与利用Henke的经验公式^[1]计算给出的响应曲线比较，其结果与理论较符合。     

X射线在Be、C轻材料上的散射特性研究

介绍了在Ru-200 X光机上,采用Ag靶的韧致辐射谱,通过LiF晶体分光产生单色X射线,用Be、C材料作散射体,在6°～40°的方向上作散射测量.实验结果显示这两种低Z材料对X光散射具有方向性.给出了散射效率随散射角度的分布曲线,阐明这种方向性与X-射线能量E、散射体的原子序数Z和强散射角θ之间的关系.     

低注量X射线中屏蔽电缆的系统电磁脉冲响应研究

介绍了在低注量X光条件下进行电缆的系统电磁脉冲实验研究的方法。将DPF低注量脉冲X光响应实验与实验室电流注入方法相结合,对典型实用电缆的系统电磁脉冲响应情况进行了实验研究,结果表明该方法对于电缆的研究是切实可行的,克服了由于缺乏高注量X光装置带来的困难。     

基于晶体衍射的X射线偏振源

基于X射线的晶体衍射,实验设计并搭建了X射线偏振源.该X射线偏振源主要包括X射线光管和用于起偏的布拉格晶体.当X射线以45°角入射到晶体表面上时,经过布拉格衍射,可以得到线偏振的X射线;当X射线的入射角度偏离45°时,将产生部分偏振X射线.实验中利用微通道铅玻璃板做准直器,很好地保证了入射角的大小和X射线的透过率.实验中使用的晶体是LiF晶体和CaF2晶体,并分别用连续能量的X射线和单一能量的特征X射线入射到晶体上,产生能量分别为6.10和4.54 keV的线偏振源,并利用二次衍射的方法对产生的偏振源进行了测量.     

北京同步辐射软X射线装置与软X射线探测器标定

软X射线计量标准的建立和软X射线探测器标定是目前国内急需解决的课题，本简单介绍了两套北京同步辐射软X射线装置，它们主要用于软X射线光学元件测量和软X射线探测元、器件的标定。另外给出了近年来在软X射线测量装置上开展的计量标准和探测器标定方面的研究结果。     

类GEM用于X光电子能量沉积增益的实验研究

GEM是一种具有高增益、高时间分辨和空间分辨等优点的新型探测器,仿照其结构设计制作了具有与其相似功能的类GEM.实验研究了类GEM对X光电子在吸收介质中能量沉积的增益特性,实验结果表明类GEM对X光电子在介质中的能量沉积增益是明显的,最大能量沉积能增加40%以上.给出了进一步提高X光电子能量沉积的建议,展望了类GEM倍增X光电子的能量沉积方式在硬X射线成像中的应用前景.     

ST401塑料闪烁体脉冲X射线相对灵敏度标定方法

介绍了脉冲X射线在ST401塑料闪烁体上的相对灵敏度标定方法,并在"晨光号"脉冲X射线源和钴辐照源上,实验标定了厚度从1～50 mm的六种规格塑料闪烁体的相对灵敏度,并给出了标定数据的不确定度评定,其标定数据能够作为ST401塑料闪烁体相对灵敏度转换的实验依据.     

小型化软X光能谱仪研制

为研制小型化软X光能谱仪,首先研制了一批小型化软X光探测元器件,包括中子辐照的砷化镓探测器、质子辐照的砷化镓探测器、多层膜反射镜、平面镜和小型化X射线二极管(XRD)等等。配置了多层镜光电导软X光能谱仪、平面镜小XRD软X光能谱仪和平面镜光电导软X光能谱仪等。这些谱仪都在“神光”Ⅱ上做了考核实验,并对这些谱仪作出了客观的评价。     

北京同步辐射软X射线装置与软X射线探测器标定

简单介绍了2套北京同步辐射软X射线装置，主要用于软X射线光学元件测量和软X射线探测元、器件的标定。给出了在软X射线测量装置上计量标准和探测器标定方面的研究结果。     

X光透镜在X射线衍射技术中的应用

用整体平行束X光透镜代替常规衍射仪的索拉狭缝和/或附加狭缝,入射和衍射X光强度可提高1.5―3.5倍,分辨率可达0.4°,可用于薄膜、粉末样品和离子束沉积样品的分析。将微会聚X光透镜应用于生物大分子衍射、高压X射线衍射、四圆X射线衍射3个不同的衍射领域,在相同X光源功率条件下,使用X光透镜后的衍射强度提高到原来的3―10倍,信噪比和分辨率有不同程度的改善。     

使用X光聚束系统的X射线荧光分析研究

复合光导管组成的Ｘ光透镜可将发散的Ｘ光束聚至直径φ０．５ｍｍ，聚束后的功率密度增加１０＾４倍，这种新型的Ｘ光透镜已用于Ｘ射线荧光分析研究，使用Ｘ光管功率仅２Ｗ，而探测限可达１０＾－９－１０＾１０ｇ．     

A microfocus X-ray tube based on a microstructured X-ray target

We present a novel concept to develop a microfocus X-ray tube based on a microstructured X-ray target that is irradiated with a nonfocused electron beam. X-ray emissions from the microstructured targets with various morphologies were studied using Monte-Carlo simulation code MCNP5. The calculations revealed that the microstructured targets are quite capable of minimizing the effective X-ray spot size compared with those of conventional transmission-type X-ray targets. Based on the simulation results of X-ray brightness, optimum geometric parameters were derived for the microstructured targets with different morphologies. Moreover, the stability of the microstructured target against heat loads delivered by an electron beam was also investigated under both the continuous and pulsed operation modes. From the analysis, the limitations of the maximum allowable electron beam currents for the stable operation of the X-ray targets are presented. The combination of the microstructured targets and nonfocused electron beam allows the miniaturization of a microfocus X-ray tube by eliminating the needs for massive and complex focusing devices.     

X-ray scattering in X-ray fluorescence spectra with X-ray tube excitation - Modelling, experiment, and Monte-Carlo simulation

X-ray scattering may contribute significantly to the spectral background of X-ray fluorescence (XRF) spectra. Based on metrological measurements carried out with a scanning electron microscope (SEM) having attached a well characterised X-ray source (polychromatic X-ray tube) and a calibrated energy dispersive X-ray spectrometer (EDS) the accuracy of a physical model for X-ray scattering is systematically evaluated for representative samples. The knowledge of the X-ray spectrometer efficiency, but also of the spectrometer response functions makes it possible to define a physical spectral background of XRF spectra. Background subtraction relying on purely mathematical procedures is state-of-the-art. The results produced by the analytical model are at least as reliable as those obtained by Monte-Carlo simulations, even without considering the very challenging contribution of multiple scattering. Special attention has been paid to Compton broadening. Relevant applications of the implementation of the analytical model presented in this paper are the prediction of the limits of detection for particular cases or the determination of the transmission of X-ray polycapillary lenses.     

Optimization of X-ray target parameters for a high-brightness microfocus X-ray tube

Parameters of a transmission-type X-ray target have been optimized for a microfocus X-ray tube with an emphasis on maximizing the intensity of X-rays generated from the target while reducing the X-ray focal spot size. Monte Carlo simulation code MCNPX was used for the calculation of X-ray intensity generated from the X-ray tube. The calculation shows that the target thickness plays a dominant role in the enhancement of X-ray intensity. The optimum thickness to get maximum X-ray intensity for a given beam current was derived from the calculation for a broad range of electron energies from 30 keV to 150 keV. In addition, stability of a transmission-type target against localized thermal loading, which is attributed to the electron beam impinging on a micron-sized target region, was also investigated by the calculation of the temperature distribution within the target. From the analysis, we present the maximum allowable electron-beam power loading for a stable operation of the transmission-type target at different incident electron beam energies.     

Soft X-ray Imaging using a Neon Filled Plasma Focus X-ray Source

A 3 kJ Mather-type UNU/ICTP plasma focus device with neon filling is used, for the first time, as a soft X-ray source for imaging of thin biological samples including insects. A charge-coupled-device (CCD) based pinhole projection system, placed in a differentially pumped chamber, is used for radiography using neon soft X-rays. The image brightness, contrast and resolution have been optimized by varying soft X-ray yield, pinhole size, camera chamber length and X-ray filters. The system can simply be modified for table-top soft X-ray microscopy of thin biological samples.     

X射线吸收光谱技术中的滤光片研制

在同步辐射X射线吸收光谱(XAS)实验中,X射线滤光片用于吸收样品的康普顿散射和弹性散射,改善荧光信号的质量。我们将ZnO颗粒分散在聚氨酯溶液里,通过恰当的喷涂工艺,获得ZnO滤片。X射线衍射(XRD),X射线荧光(XRF)及X射线吸收光谱(XAS)实验结果表明：在滤片制备过程中,ZnO结构保持不变。进一步地,ZnO滤片用于测量Ga2O3的GaK边XAS谱,显示出好的信噪比。采用同样的方法还制备了其它X射线滤光片,表明这种X射线滤光片制备技术的可行性和实用性。     

X-ray scattering in X-ray fluorescence spectra with X-ray monochromatic, polarised excitation - Modelling, experiment, and Monte-Carlo simulation

A systematic series of measurements has been carried out with monochromatic X-ray excitation with synchrotron radiation in order to check a physical model on X-ray scattering. The model has recently been successfully tested for the case of polychromatic, unpolarised excitation emitted by an X-ray tube. Our main purpose is the modelling of a physical background in X-ray fluorescence spectra, so that improved quantitative results can be achieved especially for strongly scattering specimens. The model includes single Rayleigh and Compton scattering in the specimen, the effect of bound electrons, the challenging Compton broadening and the polarisation degree. Representative specimens, measurement geometries and excitation energies have been selected with synchrotron monochromatic light at BAMline/BESSY II. Monte-Carlo simulations have been also carried out in order to evaluate the quality of the results achieved with the model.     

CdTe semiconductor X-ray imaging sensor and energy subtractionmethod using X-ray energy information

A multichannel X-ray imaging sensor using a CdTe compound semiconductor radiation detector was developed. Both the digital X-ray imaging and energy-information-generating analyzing method were studied. The X-ray imaging sensor consisted of 512-channel CdTe detector elements at a pitch of 0.2 mm. X-ray photons were directly detected using a photon-counting method and high- and low-energy images were obtained simultaneously. The specific resolution was obtained over 2.5 line pairs/mm in the channel direction and 1.6 line pairs/mm in the scanning direction with a scanning pitch of 0.2 mm. The energy subtraction method was found to be effective in distinguishing an object's component materials