scholarly journals A spectroscopic analysis of near solid density plasmas

1999 ◽  
Vol 17 (3) ◽  
pp. 477-485
Author(s):  
R. SMITH ◽  
G.J. TALLENTS ◽  
S.J. PESTEHE ◽  
G. HIRST ◽  
J. LIN ◽  
...  
Keyword(s):  
Spectroscopic Analysis ◽  
Short Pulse ◽  
Radiative Properties ◽  
X Ray ◽  
Low Intensity ◽  
Solid Density ◽  
Long Duration ◽  
Electron Density And Temperature ◽  
Material Energy

Targets of thin (0.1 μm) Al buried beneath 0.1 μm plastic overlay have been irradiated by the 350 fs CPA pulse from the 248 nm Titania KrF laser at irradiances of 1017 W/cm2. We report a study of the radiative properties of the Al plasma using X-ray emission spectroscopy. It is demonstrated that short-pulse irradiation of buried-layer targets can produce a plasma with close to solid densities and electron temperatures of several hundred eV. We examine the effect that a long duration (5–50 ns) low intensity (∼5 × 108 W/cm2) prepulse has on the measured values of electron density and temperature. The experimental technique will allow the determination of the accuracy of LTE radiative calculations in this new regime of extremely high material energy density.

Demonstration of thin film compression for short-pulse X-ray generation

2019 ◽  
Vol 34 (34) ◽  
pp. 1943015
Author(s):  
D. M. Farinella ◽  
M. Stanfield ◽  
N. Beier ◽  
T. Nguyen ◽  
S. Hakimi ◽  
...  
Keyword(s):  
Thin Film ◽  
Imaging System ◽  
Short Pulse ◽  
Laser Pulses ◽  
Single Cycle ◽  
X Ray ◽  
Ultrafast Laser Pulses ◽  
Solid Density ◽  
Fs Laser ◽  
Gaussian Mode

Thin film compression to the single-cycle regime combined with relativistic compression offers a method to transform conventional ultrafast laser pulses into attosecond X-ray laser pulses. These attosecond X-ray laser pulses are required to drive wakefields in solid density materials which can provide acceleration gradients of up to TeV/cm. Here we demonstrate a nearly 99% energy efficient compression of a 6.63 mJ, 39 fs laser pulse with a Gaussian mode to 20 fs in a single stage. Further, it is shown that as a result of Kerr-lensing, the focal spot of the system is slightly shifted on-axis and can be recovered by translating the imaging system to the new focal plane. This implies that with the help of wave-front shaping optics the focusability of laser pulses compressed in this way can be partially preserved.

Intensity and Distribution of Background X-rays in Wavelength Dispersive Spectrometry III

1989 ◽  
Vol 33 ◽  
pp. 521-529
Author(s):  
Tomoya Arai ◽  
Takashi Shoji
Keyword(s):  
Spectroscopic Analysis ◽  
Electron Excitation ◽  
Major Elements ◽  
X Rays ◽  
Fundamental Feature ◽  
X Ray ◽  
Wavelength Dispersive Spectrometry ◽  
Low Concentrations ◽  
Ppm Level

In the spectroscopic analysis of composite elements by x-ray fluorescence (XRF), it is the fundamental feature of this method that the background x-ray intensity is lower than that with electron excitation. However, the background x-rays of this method, which consist of Thomson (Rayleigh) and Compton scattered x-rays from the primary radiation, impair the analytical performance at the ppm level. In order toinvestigate the intensity of the background x-rays precisely,the study was conducted in two parts. The first part compared the measured and theoretically calculated x-ray intensities for Rh Kα and Rh Kβ peaks from various materials. The second part examined the determination of low concentrations of lead,arsenic and colonium in steel samples. The variation in the background x-ray intensities of the analyzed elements was found to be caused by the variation of the major elements and a correction equation for it is derived.

X-ray fluorescence spectroscopic analysis of bromine in pharmaceutical formulations

1991 ◽  
Vol 56 (11) ◽  
pp. 2229-2233 ◽  
Author(s):  
Maria Augusta Raggi ◽  
Federico Lucchini ◽  
Paolo Da Re
Keyword(s):  
Fluorescence Spectroscopy ◽  
Matrix Effect ◽  
Spectroscopic Analysis ◽  
High Reliability ◽  
Internal Standard ◽  
Pharmaceutical Formulations ◽  
Accurate Method ◽  
Solid Samples ◽  
X Ray

A fast and accurate method is proposed for the determination of bromine in pharmaceutical formulations. The method is based on the application of X-ray fluorescence spectroscopy to solid samples and can be used for the assay of total bromine in various chemical media. It has high reliability provided that the appropriate matrix effect correction is employed, through the use of the scattered W-line from the X-ray tube as an internal standard.

Determination of Anisotropic Absorption and Extinction Coefficients of a Tomographed Real Porous Medium

2004 ◽  
Author(s):  
Barbar Zeghondy ◽  
Jean Taine ◽  
Estelle Iacona
Keyword(s):  
Solid Phase ◽  
Fluid Phase ◽  
Radiative Properties ◽  
High Porosity ◽  
Absorption Coefficients ◽  
Extinction Coefficients ◽  
X Ray ◽  
Isotropic Media ◽  
Transfer Method

The direct general identification method of the radiative properties of high porosity media, developed and validated for virtual statistically isotropic media in [1], has been applied to a real statistically anisotropic medium. This medium has a transparent fluid phase and an opaque gray diffuse solid phase. It is modelled by a semi-transparent equivalent medium characterized by extinction and absorption coefficients β and κ. These quantities are directly determined from the morphology data obtained by X-ray tomography and from the absorptivity of the solid phase. The application of this approach to a mullite sample has established that β and κ are homogeneous but depend on direction. This last feature has to be accounted for by a radiative transfer method for this type of medium.

scholarly journals Revisit to diffraction anomalous fine structure

2014 ◽  
Vol 21 (6) ◽  
pp. 1247-1251 ◽  
Author(s):  
T. Kawaguchi ◽  
K. Fukuda ◽  
K. Tokuda ◽  
K. Shimada ◽  
T. Ichitsubo ◽  
...  
Keyword(s):  
Fine Structure ◽  
Local Structure ◽  
Spectroscopic Analysis ◽  
Direct Determination ◽  
Polycrystalline Sample ◽  
X Ray Diffraction ◽  
X Ray ◽  
Area Detector ◽  
State And Local

The diffraction anomalous fine structure (DAFS) method that is a spectroscopic analysis combined with resonant X-ray diffraction enables the determination of the valence state and local structure of a selected element at a specific crystalline site and/or phase. This method has been improved by using a polycrystalline sample, channel-cut monochromator optics with an undulator synchrotron radiation source, an area detector and direct determination of resonant terms with a logarithmic dispersion relation. This study makes the DAFS method more convenient and saves a large amount of measurement time in comparison with the conventional DAFS method with a single crystal. The improved DAFS method has been applied to some model samples, Ni foil and Fe3O4powder, to demonstrate the validity of the measurement and the analysis of the present DAFS method.

scholarly journals Spectroscopic analysis of short-pulse laser-produced plasmas

1994 ◽  
Vol 12 (3) ◽  
pp. 455-462 ◽  
Author(s):  
J.P. Matte ◽  
J.C. Kieffer ◽  
M. Chaker ◽  
C.Y. Côté ◽  
Y. Beaudoin ◽  
...  
Keyword(s):  
Spectroscopic Analysis ◽  
Short Pulse ◽  
Electron Distribution Function ◽  
Line Broadening ◽  
Ion Temperature ◽  
Electronic Density ◽  
X Ray ◽  
Dense Plasmas ◽  
Tantalum Target ◽  
Short Pulse Laser

Experimental spectra of hot dense plasmas of aluminium produced by the interaction of a subpicosecond laser with solid targets at 1016 and 5 × 1017 W/cm2 are analyzed and discussed. A detailed analysis of the K-shell spectra is given through time-dependent calculations of atomic physics postprocessed to Fokker-Planck calculations of the laser-matter interaction. The non-Maxwellian character of the electron distribution function is shown. An evaluation of the electronic density and of the ion temperature 7i will be presented through Stark line broadening calculations. An X-ray spectrum from a Tantalum target also will be presented along with a preliminary interpretation.

Lateral resolution of the electron microbeam analysis

1978 ◽  
Vol 36 (1) ◽  
pp. 542-543
Author(s):  
H.J. Dudek
Keyword(s):  
Quantitative Analysis ◽  
Depth Resolution ◽  
Lateral Resolution ◽  
Cylindrical Particle ◽  
Correction Procedure ◽  
X Ray ◽  
Element Concentrations ◽  
Microbeam Analysis ◽  
The Matrix

The chemical inhomogenities in modern materials such as fibers, phases and inclusions, often have diameters in the region of one micrometer. Using electron microbeam analysis for the determination of the element concentrations one has to know the smallest possible diameter of such regions for a given accuracy of the quantitative analysis.In th is paper the correction procedure for the quantitative electron microbeam analysis is extended to a spacial problem to determine the smallest possible measurements of a cylindrical particle P of high D (depth resolution) and diameter L (lateral resolution) embeded in a matrix M and which has to be analysed quantitative with the accuracy q. The mathematical accounts lead to the following form of the characteristic x-ray intens ity of the element i of a particle P embeded in the matrix M in relation to the intensity of a standard S

Sem and X-Ray Analysis of Renal and Biliary Calculi

1976 ◽  
Vol 34 ◽  
pp. 306-307
Author(s):  
R. J. Narconis ◽  
G. L. Johnson
Keyword(s):  
Chemical Constituents ◽  
Natural State ◽  
X Ray Diffraction ◽  
Chemical Methods ◽  
X Ray ◽  
Additional Dimension ◽  
Biliary Calculi ◽  
Calculus Formation ◽  
Scanning Electron

Analysis of the constituents of renal and biliary calculi may be of help in the management of patients with calculous disease. Several methods of analysis are available for identifying these constituents. Most common are chemical methods, optical crystallography, x-ray diffraction, and infrared spectroscopy. The application of a SEM with x-ray analysis capabilities should be considered as an additional alternative.A scanning electron microscope equipped with an x-ray “mapping” attachment offers an additional dimension in its ability to locate elemental constituents geographically, and thus, provide a clue in determination of possible metabolic etiology in calculus formation. The ability of this method to give an undisturbed view of adjacent layers of elements in their natural state is of advantage in determining the sequence of formation of subsequent layers of chemical constituents.

Preparation And elemental analysis of ancient fibers

1987 ◽  
Vol 45 ◽  
pp. 410-411
Author(s):  
Allen Angel ◽  
Kathryn A. Jakes
Keyword(s):  
Cross Sections ◽  
Physical Structure ◽  
Energy Dispersive ◽  
Archaeological Sites ◽  
X Ray ◽  
Long Term Storage ◽  
Backscattered Electron ◽  
Electron Imaging

Fabrics recovered from archaeological sites often are so badly degraded that fiber identification based on physical morphology is difficult. Although diagenetic changes may be viewed as destructive to factors necessary for the discernment of fiber information, changes occurring during any stage of a fiber's lifetime leave a record within the fiber's chemical and physical structure. These alterations may offer valuable clues to understanding the conditions of the fiber's growth, fiber preparation and fabric processing technology and conditions of burial or long term storage (1).Energy dispersive spectrometry has been reported to be suitable for determination of mordant treatment on historic fibers (2,3) and has been used to characterize metal wrapping of combination yarns (4,5). In this study, a technique is developed which provides fractured cross sections of fibers for x-ray analysis and elemental mapping. In addition, backscattered electron imaging (BSI) and energy dispersive x-ray microanalysis (EDS) are utilized to correlate elements to their distribution in fibers.

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