紫外-可见光双通道拉曼光谱仪光学设计

紫外拉曼光谱技术具有高强度拉曼散射、无荧光干扰的特点;可见光拉曼光谱技术可实现低波数、高分辨率探测。为兼具两种激发波长的优势,设计了一款对称分布的双Czerny-Turner光路聚焦于一个探测器的双通道拉曼光谱仪。通过元器件的选型和初始结构的计算,在不增加多余元器件的情况下,对弧矢方向像散进行补偿,避免了像面上的能量损失。配合Zemax软件对双通道光谱分别进行建模优化,最终实现了对400~5000 cm^-1（266 nm激发）和50~3500 cm^-1（633 nm激发）两段光谱的同时探测。均方根半径、点列图和调制传递函数等评价指标有效验证了设计的合理性和可行性。结果表明,两套拉曼光谱仪分别可达8 cm^-1和5 cm^-1分辨率,本设计具有高分辨率、低波数、多波长激发、集成化等优势。     

Confocal micro-x-ray fluorescence spectrometer for light element analysis

An existing micro-x-ray fluorescence (micro-XRF) spectrometer designed for light element analysis (6 ≤ Z ≤ 14) has been extended to confocal geometry: a second polycapillary x-ray optic has been introduced in front of the energy dispersive x-ray detector. New piezo positioners for optimum alignment of both optics have been installed inside the vacuum chamber. The spectrometer offers now the possibility of true 3D elemental analysis in the micrometer regime. Depth resolution varies between 100 μm at 1 keV fluorescence energy (Na-Kα) and 30 μm for 17.5 keV (Mo). To further extend analytical capabilities a second x-ray tube with a Rh anode has been acquired to supplement to existing Mo anode tube. Lower limits of detection have been determined to be in the ppm region for confocal geometry. The spectrometer has been characterized and tested using different samples. Furthermore, results have been compared with SR micro-XRF to show the capabilities and limitations of this spectrometer.     

Characterization of a polarization-resolved high spectral resolution UV-visible spectrometer

To measure the degree of polarization of a plasma emission, a polarization-resolved UV-visible Czerny-Turner-type spectrometer was designed and constructed. For a high spectral resolution, F=1 m mirrors were used as a focusing and collimating mirrors and the incidence angles to the mirrors were determined to eliminate coma. The effect of astigmatism was reduced by designing the incidence angles to the mirrors to be as small as possible. The flat focal plane condition proposed by Reader [J. Opt. Soc. Am. 59, 1189 (1969)] was used to determine the grating position. The measured spatial resolution was 170 microm. To simultaneously measure the intensities with two perpendicular polarizations, a calcite crystal was placed after the entrance slit of the spectrometer. The change in the imaging property of the spectrometer due to the calcite crystal was measured and minimized. The spectral resolution was experimentally measured with a laser produced plasma to be 0.05 nm at 348 nm. The resolving power measured is 6600.     

Supermini型X射线荧光光谱仪的故障分析

总结了该仪器真空系统、X射线发生单元故障处理的工作经验。重点介绍了根据仪器故障报警内容,结合电路原理和相关部件的机械机构,分析、查找故障原因的方法。     

Qualification of a fluorescence spectrometer for measuring true fluorescence spectra

New analytical methods using fluorescence detection are becoming increasingly quantitative and require easy-to-use material standards for fluorometer qualification and method validation. NIST is responding to this need by developing and producing such standards. Reported here is the first step in this process, which is to qualify a research-grade fluorescence spectrometer for measuring true fluorescence spectra of reference material candidates. "True" spectra are defined here as those with fluorescence intensity, either relative or absolute as required, and wavelength both being reported with high accuracy and known precision, after wavelength has been calibrated and corrections for excitation intensity and detection system response have been applied. The uncertainties determined in relative and absolute intensity-corrected fluorescence spectra using both calibrated source (CS)- and calibrated detector (CD)-based methods were compared. The CS-based method gave uncertainties, typically about +/-5% for relative spectral correction, that were about half that of the CD-based method for determining both relative and absolute spectral correction factors. Absolute spectral correction factors can be determined using either method without knowing the optical geometry of the instrument. The absolute spectral correction factors were found to have much larger uncertainties than the corresponding relative correction factors with uncertainties for the CS-based method of +/-10% to +/-15% being typical and +/-20% or more not being uncommon, particularly for excitation and emission wavelengths below 400 nm. Uncertainties arising from detection system nonlinearity and instrument polarization ratios were also explored.     

X荧光光谱仪对焦炭成分的分析

本文介绍用X射线荧光光谱仪分析焦炭中P_2O_5、Al_2O_3、CaO含量的分析方法,该法分析速度快,结果准确。     

理学3370E X荧光光谱分析仪的故障分析及处理

本文主要介绍理学3370E Ⅹ荧光光谱分析仪几例电路故障的分析及处理。     

利用X荧光能谱仪快速测定合金钢中钛元素

在合金钢能量色散X射线荧光光谱的研究基础上,使用国产的XRF-6型X射线荧光能谱仪对合金钢中钛元素进行了分析技术研究。钛元素的Kα特征射线能量值为4.51keV,与特征能量值为4.66keV的FeKα逃逸峰叠加重合,严重干扰钛元素的测定。研究了铁元素逃逸峰干扰的快速扣除方法,得到FeKα峰比例扣除、FeKα逃逸峰高能侧对称扣除法和TiKα峰低能侧对称积分法等快捷处理方法。工作曲线的制作和实际样品测定结果证明几种快速分析方法是可靠准确的。     

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.     

原子荧光光谱仪改进意见

本文讨论了原子荧光光谱仪在技术和应用方面可以改进的地方。     

荧光光谱仪红外波段荧光强度的校正

一般荧光光谱仪由于光栅闪耀效果和OCD响应下降，导致1μm波长附近接收到的荧光发射信号减弱。本文介绍一种通过数学处理和基线调整校整荧光光谱仪红外波段荧光强度的方法，从而可以在一般荧光光谱仪上获得与高档荧光光谱仪接近的荧光光谱图。     

AF-640原子荧光光谱仪常见故障维修

介绍了AF-640双道原子荧光光谱仪的常见故障和处理方法.     

MagiX型X射线荧光光谱仪故障排除方法

介绍了MagiX型X射线荧光光谱仪在使用过程中的常见故障,分析了故障产生的原因,提出了解决办法和使用中应注意的事项.     

一种120～300 nm紫外-真空紫外激发/荧光光谱测量装置

介绍了一种可用于120～300 nm激发的荧光粉发射光谱,激发光谱和相对亮度测量的紫外-真空紫外单色仪/荧光光谱仪装置.发射光谱的测量范围为380～780 nm.该仪器由真空紫外光源、真空紫外光谱仪、样品室、真空泵、平像场荧光光谱仪、光电倍增管等部分组成.真空紫外光源采用Cathodeon公司的30 W氘灯,真空紫外光谱仪为美国ActonResearch公司的VM-502 0.2 m单色仪,CCD探测器采用日本滨松公司的S3921型自扫描二极管阵列.测试结果表明该仪器的光谱重复性和准确性好于1%,样品色坐标的重复性和准确性均好于0.001.     

原子荧光仪测定砷实验条件的优化

原子荧光仪在测定砷时,载流浓度、硼氢化钾浓度、样品酸度、硫脲浓度、负高压、灯电流对于实验结果均有影响,实验通过Minitab 17软件设计正交试验。实验结果表明:第10、21组实验的线性关系式小于0.999,其他实验组的线性关系式良好,且大于0.999;检出限分别为0.012μg/L^0.214μg/L之间。其中第14组实验的检出限最低为0.012μg/L,第1组实验的检出限最高为0.214μg/L;精密度结果为0.37%~11.39%之间,准确度结果在-2.14%^-73.35%之间。其中27组实验的精密度最好,为0.37%,第12组实验的准确度最好,为-2.14%。对于荧光强度的影响分别为B硼氢化钾浓度>F灯电流>E负高压>D硫脲浓度>C样品酸度>A载流浓度;对于检出限的影响分别为B硼氢化钾浓度>F灯电流>C样品酸度>E负高压>D硫脲浓度>A载流浓度;精密度的影响分别为B硼氢化钾浓度>D硫脲浓度>E负高压>A载流浓度>C样品酸度>F灯电流;准确度的影响分别为C样品酸度>B硼氢化钾浓度>D硫脲浓度>F灯电流>E负高压。     

A practical electron spectrometer for chemical analysis

This paper describes the basic parameters which have been considered in the design of a practical electron spectrometer optimized for micro-chemical analysis in a 100 kV transmission electron microscope fitted with a scanning unit. Constructional factors and the operation of this spectrometer are discussed, as well as data acquisition. Typical results are presented to illustrate the operative modes. Both the prototype spectrometer and subsequent copies of it now are being utilized sucessfully in studies related to materials and biological sciences.     

Ion beam nanopatterning and micro-Raman spectroscopy analysis on HOPG for testing FIB performances

This work reports Ga⁺ focused ion beam nanopatterning to create amorphous defects with periodic square arrays in highly oriented pyrolytic graphite and the use of Raman spectroscopy as a new protocol to test and compare progresses in ion beam optics, for low fluence bombardment or fast writing speed. This can be ultimately used as a metrological tool for comparing different FIB machines and can contribute to Focused Ion Beam (FIB) development in general for tailoring nanostructures with higher precision. In order to do that, the amount of ion at each spot was varied from about 10⁶ down to roughly 1 ion per dot. These defects were also analyzed by using high resolution scanning electron microscopy and atomic force microscopy. The sensitivities of these techniques were compared and a geometrical model is proposed for micro-Raman spectroscopy in which the intensity of the defect induced D band, for a fixed ion dose, is associated with the diameter of the ion beam. In addition, the lateral increase in the bombarded spot due to the cascade effect of the ions on graphite surface was extracted from this model. A semi-quantitative analysis of the distribution of ions at low doses per dot or high writing speed for soft modification of materials is discussed.     

空间光谱仪指向机构的力学分析

为了准确分析空间CO2光谱仪指向机构的力学特性,本文根据轴承结构参数,建立了轴承有限元接触分析模型。计算了不同载荷下轴心的位移量,用多项式对计算结果进行拟合得到轴承非线性刚度曲线。在指向机构有限元力学模型中,利用相应刚度的弹簧单元替代轴承结构,经过有限元频率响应分析后获得指向机构的动态特性。仿真实验显示:在重力工况下指向镜的面形在光轴和子午方向分别为19.23nm和19.27nm,满足优于λ/30(均方根值RMS,λ=632.8nm)的设计要求,3个方向基频均大于100Hz。振动试验显示,3个方向基频均优于100 Hz,振动试验后反射镜镜面面形精度为λ/35。分析结果与仿真结果相符,表明利用非线性接触分析方法可以较为准确地求解轴承刚度,同时空间光谱仪指向机构静/动力学性能满足设计要求。