Elemental composition x-ray fluorescence analysis with a TES-based high-resolution x-ray spectrometer

The accurate analysis of the elemental composition plays a crucial role in the research of functional materials.The emitting characteristic x-ray fluorescence(XRF)photons can be used for precisely discriminating the specified element.The detection accuracy of conventional XRF methodology using semiconductor detector is limited by the energy resolution,thus posing a challenge in accurately scaling the actual energy of each XRF photon.We adopt a novel high-resolution x-ray spectrometer based on the superconducting transition-edge sensor(TES)for the XRF spectroscopy measurement of different elements.Properties including high energy resolution,high detection efficiency and precise linearity of the new spectrometer will bring significant benefits in analyzing elemental composition via XRF.In this paper,we study the Ledge emission line profiles of three adjacent rare earth elements with the evenly mixed sample of their oxide components:terbium,dysprosium and holmium.Two orders of magnitude better energy resolution are obtained compared to a commercial silicon drift detector.With this TES-based spectrometer,the spectral lines overlapped or interfered by background can be clearly distinguished,thus making the chemical component analysis more accurate and quantitative.A database of coefficient values for the line strength of the spectrum can then be constructed thereafter.Equipped with the novel XRF spectrometer and an established coefficient database,a direct analysis of the composition proportion of a certain element in an unknown sample can be achieved with high accuracy.

X-RAY FLUORESCENCE SPECTRA ANALYSIS ON THE STRUCTURE AROUND Ti^(4+) OF BaO-SiO_2-B_2O_3-TiO_2 SYSTEM GLASSES

The structure around Ti^(4+) in Bao-SiO_2 -B_2O_3-TiO_2 had been studied by X-ray fluorescence spectra. The results show that the Ti^(4+) mainly exists in the [TiO_4] and enters the network of [SiO_4]. [TiO_4] has the tendency to change to [TiO_6] with the increase of TiO_2 con-tent. When the TiO_2 content increases to about 20mol% the tendency reaches its maximum.

Development of the Data Processing and Analysis System Framework for ICF Experiments

An idea is presented about the development of a data processing and analysis system for ICF experiments, which is based on an object oriented framework. The design and preliminary implementation of the data processing and analysis framework based on the ROOT system have been completed. Software for unfolding soft X-ray spectra has been developed to test the functions of this framework.

溶剂浸渍滤纸的制备及其在XRFA中的应用研究（二）──XRFA中溶剂浸渍滤纸制样法研究

本文报道了Ｐ５０７溶剂浸渍滤纸（ＳＩＦＰ）的制备方法及应用溶剂浸渍滤纸富集金属离子制备适合Ｘ射线荧光光谱分析样片的方法。在ｐＨ３介质中制备了Ｌａ（Ⅲ），Ｃｅ（Ⅲ），Ｙｂ（Ⅲ）；在ｐＨ２．５的介质中制备了Ｔｈ（Ⅳ）；在２ｍｏｌ／ＬＨＣｌ介质中制备了Ｚｒ（Ⅳ）与Ｈｆ（Ⅳ）等元素的标准系列样片。本文报道了经ＸＲＦ测定的数据。各元素的检出限ＣＤＬ分别为Ｌａ：０．３１５μｇ（Ｌａ２Ｏ３）；Ｃｅ：０．３５９μｇ（ＣｅＯ２）；Ｙｂ：０．７０９μｇ（Ｙｂ２Ｏ３）；Ｔｈ：０．６２２μｇ（ＴｈＯ２）；Ｚｒ：０．６６６μｇ（Ｚｒ）；Ｈｆ：１．０８μｇ（Ｈｆ）。样片稳定时间约四个月。本文还对制备ＳＩＦＰ时滤纸的选择，制备样片时溶液通过ＳＩＦＰ的次数等方面进行了讨论。

Chemical composition and Mott-Schottky analysis of passive film formed on G3 alloy in bicarbonate/carbonate buffer solution

The chemical composition and semi-conductive properties of passive film on nickel- based alloy （G3 alloy） in bicarbonate/carbonate buffer solution were investigated by Auger electron spectroscopy （AES）, X-ray photoelectron spectroscopy （XPS）, elec- trochemical impedance spectra （EIS） and Mott-Schottky plot. AES and XPS results showed that the passive film appeared double-layer structure, in which the inner film was composed of nickel oxide, the mixed nickel-chromium-molybdenum-manganese oxides were the major component of the outer film. The electrochemical results revealed that the factors including frequency, potential, time, temperature and pH value can affect the semi-conductive property, the doping densities decreased with increasing potential and pH value, prolonging time and decreasing temperature. According to the above results, it can be concluded that the film protection on the substrate was enhanced with increasing potential and pH value, prolonging time and decreasing temperature.

Mineralogical and Geochemical Characteristics of Caprock Formations Used for Storage and Sequestration of Carbon Dioxide

The main objective of the present study is to characterize cap rock formation used for geological storage of carbon dioxide (CO2). The petrophysical properties of several rocks were studied before CO2 injection. This step is necessary for an understanding of CO2-brine-rock interactions. The mineralogical composition of several clay samples collected from real storage sites located in the south of Tunisia was determined by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) coupled to a probe EDS, infrared spectroscopy, thermal analysis and fluorescence spectra. The obtained experimental results reveal that illite, calcite and quartz are the dominant clay minerals. Dolomite and albite are also present. Besides, SEM analysis shows laminated structure for these samples which suggests low crystallinity. This sample contains a higher content of Fe, Cl, Ca and O. The clay cover may also be useful in storage process by immobilizing the migration of CO2 outer of the geological site and activating the process of mineral sequestration.

Physical parameter estimation with MCMC from observations of Vela X-1

We present a parameter estimate for continua, and He-like triplets of the high resolution X-ray spectra with a Bayesian inference and a Markov Chain Monte Carlo(MCMC) tool. The method is applied for Vela X-1 with three different orbital phases(φ), Eclipse, φ = 0.25, and φ = 0.5, which are adopted from the Chandra High-Energy Transmission Grating Spectrometer(HETGS). A parameterized two-component power-law model [Sako et al., Astrophys. J. 525, 921(1999)] and a multi-Gaussian model are applied to model these continua and He-like triplets, respectively. A uniform distribution over each parameter is used as the prior belief. Posterior probability distribution functions of parameters and the covariances among them are explored by using the MCMC method. The main advantages are(i) all model-based parameters are set to be free instead of artificially fixing some of the parameters during the data-model fitting;(ii) the contributions from satellite lines are considered;(iii) backgrounds are treated as a correction to the observation errors;and(iv) the confidence interval of each parameter is given. The fitted results show that the column density of scatter component(N_H^(scat)) varies from phase to phase, which imply a non-spherical structure of the stellar wind in Vela X-1.Moreover, the wind velocities derived from main lines of each set of He-like triplets show better self-consistency than those in previous publications, which could provide a reliable approach for the diagnostics of photoionized plasma in astrophysical objects and the laboratory.

Coherent emission and attosecond transient absorption of N_(2)^(+)in strong fields

The ionic dynamics induced by strong-field ionization are essential to understand the fundamental physics and chemical reactions.By solving the ionization-coupling equation theoretically,we can simultaneously address strong-field ionization and coupling dynamics in ions.By employing the driving pulse at the wavelength of 1580 nm,we show that the B^(2)Σ_(u)^(+)state of the strong field ionization created N_(2)^(+)could be populated by polarization effect and five-photon resonance but there is no population inversion between X^(2)Σ_(g)^(+)and B^(2)Σ_(u)^(+)states for the nitrogen molecular ions aligning along the laser polarization.In addition,both the ultraviolet supercontinuum and the attosecond transient absorption spectroscopy(ATAS)are calculated to illustrate the characteristics of population and coherence.The Stark shift observed from the transient absorption confirms the origin of ultraviolet supercontinuum.Our results show the evolution of the absorption spectral lineshape,varying from Lorentzian to Fano to inverted Lorentzian and back forth and the optical gain is achieved at 394 e V due to the vibrational coherent dynamics.This study offers valuable insights into the strong-field quantum optics of molecular ions.