Design and performance of a versatile curved-crystal spectrometer for high-resolution spectroscopy in the tender x-ray range

A complete in-vacuum curved-crystal x-ray emission spectrometer in Johansson geometry has been constructed for a 2-6 keV energy range with sub natural line-width energy resolution. The spectrometer is designed to measure x-ray emission induced by photon and charged particle impact on solid and gaseous targets. It works with a relatively large x-ray source placed inside the Rowland circle and employs position sensitive detection of diffracted x-rays. Its compact modular design enables fast and easy installation at a synchrotron or particle accelerator beamline. The paper presents main characteristics of the spectrometer and illustrates its capabilities by showing few selected experimental examples.     

Five-element Johann-type x-ray emission spectrometer with a single-photon-counting pixel detector

A Johann-type spectrometer with five spherically bent crystals and a pixel detector was constructed for a range of hard x-ray photon-in photon-out synchrotron techniques, covering a Bragg-angle range of 60°-88°. The spectrometer provides a sub emission line width energy resolution from sub-eV to a few eV and precise energy calibration, better than 1.5 eV for the full range of Bragg angles. The use of a pixel detector allows fast and easy optimization of the signal-to-background ratio. A concentration detection limit below 0.4 wt% was reached at the Cu Kα(1) line. The spectrometer is designed as a modular mobile device for easy integration in a multi-purpose hard x-ray synchrotron beamline, such as the SuperXAS beamline at the Swiss Light Source.     

The ITER core imaging x-ray spectrometer: x-ray calorimeter performance

We describe the anticipated performance of an x-ray microcalorimeter instrument on ITER. As part of the core imaging x-ray spectrometer, the instrument will augment the imaging crystal spectrometers by providing a survey of the concentration of heavy ion plasma impurities in the core and possibly ion temperature values from the emission lines of different elemental ions located at various radial positions.     

Triple-path collector optics for grazing incident x-ray emission spectrometer

A new type of collector optics was developed for grazing incident x-ray emission spectrometer. The collector optics used two cylindrical mirrors to add two extra light paths while keeping the center light path that directly illuminates the grating. The design and properties of the spectrometer using the triple-path collector optics were evaluated using ray-tracing simulations, and validity of this design in terms of throughput and energy resolution was confirmed by the experimentally obtained spectra.     

Ultrahigh resolution soft x-ray emission spectrometer at BL07LSU in SPring-8

An extremely high resolution flat field type slit less soft x-ray emission spectrometer has been designed and constructed for the long undulator beamline BL07LSU in SPring-8. By optimizing the ruling parameters of two cylindrical gratings, a high energy resolution ΔE < 100 meV and/or an E∕ΔE ~ 10 000 are expected for the energy range of 350 eV - 750 eV taking into account the broadening by the spatial resolution (25 μm) of a CCD detector. A coma-free operation mode proposed by Strocov et al., is also applied to eliminate both defocus and coma aberrations. The spectrometer demonstrated experimentally that E/ΔE = 10 050 and 8046 for N 1s (402.1 eV) and Mn 2p (641.8 eV) edges, respectively.     

A plastic miniature x-ray emission spectrometer based on the cylindrical von Hamos geometry

We present a short working distance miniature x-ray emission spectrometer (miniXES) based on the cylindrical von Hamos geometry. We describe the general design principles for the spectrometer and detail a specific implementation that covers Kβ and valence level emission from Fe. Large spatial and angular access to the sample region provides compatibility with environmental chambers, microprobe, and pump/probe measurements. The primary spectrometer structure and optic is plastic, printed using a 3-dimensional rapid-prototype machine. The spectrometer is inexpensive to construct and is portable; it can be quickly set up at any focused beamline with a tunable narrow bandwidth monochromator. The sample clearance is over 27 mm, providing compatibility with a variety of environment chambers. An overview is also given of the calibration and data processing procedures, which are implemented by a multiplatform user-friendly software package. Finally, representative measurements are presented. Background levels are below the level of the Kβ(2, 5) valence emission, the weakest diagram line in the system, and photometric analysis of count rates finds that the instrument is performing at the theoretical limit.     

Calibration of a high resolution grating soft x-ray spectrometer

The calibration of the soft x-ray spectral response of a large radius of curvature, high resolution grating spectrometer (HRGS) with a back-illuminated charge-coupled device detector is reported. The instrument is cross-calibrated for the 10-50 A? waveband at the Lawrence Livermore National Laboratory electron beam ion trap (EBIT) x-ray source with the EBIT calorimeter spectrometer. The HRGS instrument is designed for laser-produced plasma experiments and is important for making high dynamic range measurements of line intensities, line shapes, and x-ray sources.     

A multi-crystal wavelength dispersive x-ray spectrometer

A multi-crystal wavelength dispersive hard x-ray spectrometer with high-energy resolution and large solid angle collection is described. The instrument is specifically designed for time-resolved applications of x-ray emission spectroscopy (XES) and x-ray Raman scattering (XRS) at X-ray Free Electron Lasers (XFEL) and synchrotron radiation facilities. It also simplifies resonant inelastic x-ray scattering (RIXS) studies of the whole 2d RIXS plane. The spectrometer is based on the Von Hamos geometry. This dispersive setup enables an XES or XRS spectrum to be measured in a single-shot mode, overcoming the scanning needs of the Rowland circle spectrometers. In conjunction with the XFEL temporal profile and high-flux, it is a powerful tool for studying the dynamics of time-dependent systems. Photo-induced processes and fast catalytic reaction kinetics, ranging from femtoseconds to milliseconds, will be resolvable in a wide array of systems circumventing radiation damage.     

Double axis, two-crystal x-ray spectrometer

A two-crystal double axis x-ray spectrometer, capable of goniometric accuracy on the order of 0.1", has been developed. Some of its unique design features are presented. These include (1) a modified commercial thrust bearing which furnishes a precise, full circle theta:2theta coupling, (2) a new tangent drive system design in which a considerable reduction of the lead screw effective pitch is achieved, and (3) an automatic step scanning control which eliminates most of the mechanical deficiencies of the tangent drive by directly reading the tangent arm displacement.     

国内辉光放电光谱仪的研制

本文介绍了辉光放电光谱仪（GD—OES）的结构与基本原理。分别对仪器各部件（如辉光放电光源、直流恒流供能源、光学系统、自动控制系统、数据采集处理系统）的研制进行了详细地阐述。采用研制的辉光放电光谱仪分别对样品进行了成分分析和深度分析,取得了很好的分析结果。所研制的辉光放电光谱仪在光学系统的PMT负高压、直流恒流供能源、光源不同部位的不同抽速等多方面都有相应的技术创新。     

A new type of x-ray absorption spectrometer

A single-crystal spectrometer for x-ray absorption and emission with a microfocus x-ray source has been set up so that the divergent rays from the source can be analyzed over a wide range of Bragg angles with a high degree of resolution. The covered energy interval depends upon the exposed width of the crystal and the geometrical setup. Preliminary experiments are presented to show the effectiveness of the spectrometer.     

岛津μEDX型微区能量色散型X射线荧光光谱分析仪

本文介绍岛津公司最新的μEDX能量色散型X射线荧光光谱分析仪的特点。     

ITER-relevant calibration technique for soft x-ray spectrometer

The ITER-oriented JET research program brings new requirements for the low-Z impurity monitoring, in particular for the Be—the future main wall component of JET and ITER. Monitoring based on Bragg spectroscopy requires an absolute sensitivity calibration, which is challenging for large tokamaks. This paper describes both “component-by-component” and “continua” calibration methods used for the Be IV channel (75.9 ?) of the Bragg rotor spectrometer deployed on JET. The calibration techniques presented here rely on multiorder reflectivity calculations and measurements of continuum radiation emitted from helium plasmas. These offer excellent conditions for the absolute photon flux calibration due to their low level of impurities. It was found that the component-by-component method gives results that are four times higher than those obtained by means of the continua method. A better understanding of this discrepancy requires further investigations.     

Application of a transmission crystal x-ray spectrometer to moderate-intensity laser driven sources

In the pursuit of novel, laser-produced x-ray sources for medical imaging applications, appropriate instrumental diagnostics need to be developed concurrently. A type of transmission crystal spectroscopy has previously been demonstrated as a survey tool for sources produced by high-power and high-energy lasers. The present work demonstrates the extension of this method into the study of medium-intensity laser driven hard x-ray sources with a design that preserves resolving power while maintaining high sensitivity. Specifically, spectroscopic measurements of characteristic Kα and Kβ emissions were studied from Mo targets irradiated by a 100 fs, 200 mJ, Ti: sapphire laser with intensity of 10(17) W/cm(2) to 10(18) W∕cm(2) per shot. Using a transmission curved crystal spectrometer and off-Rowland circle imaging, resolving powers (E/ΔE) of around 300 for Mo Kα(2) at 17.37 keV were obtained with an end-to-end spectrometer efficiency of (1.13 ± 0.10) × 10(-5). This sensitivity is sufficient for registering x-ray lines with high signal to background from targets following irradiation by a single laser pulse, demonstrating the utility of this method in the study of the development of medium-intensity laser driven x-ray sources.     

Development of a time-resolved soft x-ray spectrometer for laser produced plasma experiments

A 2400 lines/mm variable-spaced grating spectrometer has been used to measure soft x-ray emission (8-22 A?) from laser-produced plasma experiments at Lawrence Livermore National Laboratory's Compact Multipulse Terrawatt (COMET) Laser Facility. The spectrometer was coupled to a Kentech x-ray streak camera to study the temporal evolution of soft x rays emitted from the back of the Mylar and the copper foils irradiated at 10(15)?W/cm(2). The instrument demonstrated a resolving power of ～120 at 19 A? with a time resolution of 31 ps. The time-resolved copper emission spectrum was consistent with a photodiode monitoring the laser temporal pulse shape and indicated that the soft x-ray emission follows the laser heating of the target. The time and spectral resolutions of this diagnostic make it useful for studies of high temperature plasmas.     

便携式拉曼光谱仪的设计

研制了适合现场使用的便携式拉曼光谱仪。介绍了仪器的特点和组成、激光光源、拉曼光纤探头和CCD光纤光谱仪。     

Portable x-ray fluorescence spectrometer for coating thickness measurement

A handheld x-ray spectrometer has been realized and tested. The purpose of the device is to measure the thickness of coated samples in the range of 1-1500 nm in an industrial environment. Accuracy of approximately 3% has been achieved in this range with a measurement time of 1 min. Automated software has been implemented to allow utilization by a nonspecialist operator. An automated calibration procedure, based on measurements of reference samples, is used.     

Calibration of a flat field soft x-ray grating spectrometer for laser produced plasmas

We have calibrated the x-ray response of a variable line spaced grating spectrometer, known as the VSG, at the Fusion and Astrophysics Data and Diagnostic Calibration Facility at the Lawrence Livermore National Laboratory (LLNL). The VSG has been developed to diagnose laser produced plasmas, such as those created at the Jupiter Laser Facility and the National Ignition Facility at LLNL and at both the Omega and Omega EP lasers at the University of Rochester's Laboratory for Laser Energetics. The bandwidth of the VSG spans the range of ～6-60?A?. The calibration results presented here include the VSG's dispersion and quantum efficiency. The dispersion is determined by measuring the x rays emitted from the hydrogenlike and heliumlike ions of carbon, nitrogen, oxygen, neon, and aluminum. The quantum efficiency is calibrated to an accuracy of 30% or better by normalizing the x-ray intensities recorded by the VSG to those simultaneously recorded by an x-ray microcalorimeter spectrometer.     

高分辨率旋转光栅光谱仪的设计

针对光栅光谱仪中高分辨率与宽光谱难以同时满足的问题,设计了一款基于旋转光栅的Czerny-Turner（C-T型）光路结构的高分辨率宽光谱拉曼光谱仪,激发波长为532 nm,光谱范围为80～3000 $ {\mathrm{c}\mathrm{m}}^{-1} $,分辨率为1.2 $ {\mathrm{c}\mathrm{m}}^{-1} $。将光谱范围分为低（80～1450 $ {\mathrm{c}\mathrm{m}}^{-1} $）、中（855～2225 $ {\mathrm{c}\mathrm{m}}^{-1} $）、高（1630～3000 $ {\mathrm{c}\mathrm{m}}^{-1} $）3个波段,以优化中波段为主,对全波段进行了优化。通过微调光栅的旋转角度,确保低、中、高波段均位于CCD的有效像面上。该光谱仪成像系统的点列图、均方根图和调制传递函数图均符合设计要求。