Characterization of pure and mixed Ar, Kr and Xe gas jets generated by different nozzles and a study of X-ray radiation yields after interaction with a sub-ps laser pulse

2016 ◽  
Vol 23 (10) ◽  
pp. 101207 ◽  
Author(s):  
K. A. Schultz ◽  
V. L. Kantsyrev ◽  
A. S. Safronova ◽  
J. J. Moschella ◽  
P. Wiewior ◽  
...  
Keyword(s):  
Laser Pulse ◽  
X Ray ◽  
Gas Jets

scholarly journals PREPARATION AND CHARACTERIZATION OF CDO-NIO NANOCOMPOSITES USING LASER PULSE DEPOSITION APPROACH

2021 ◽  
Vol 03 (03) ◽  
pp. 01-09
Author(s):  
Khamees D. MAHMOOD ◽  
Kadhim A. AADIM ◽  
Mohammed G. HAMMED
Keyword(s):  
Laser Pulse ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Energy Band Gap ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Pulse Deposition ◽  
Deposited Films

In this manuscript, CdO-NiO nanocomposites (in the form of thin film) with particular concentrations are paper using laser pulse deposition technique under the effect of different laser energies (300, 400, 500, and 600 mJ). Furthermore, the structural, morphological, and optical analyses are thoroughly investigated. In particular, well-oriented deposited films are observed by using X-ray diffraction technique, while the morphological properties are investigated using two different techniques namely field emission scanning electron microscopy and atomic force microscopy which have revealed small nanoparticles with approximate diameter of 50 nm and average surface roughness ranging between 6.5 and 20.3 nm for laser energies of 400 and 600 mJ, respectively. Continuously, the optical technique applied which used UV-Vis analysis has showed cut-off phenomenon at around 339 nm. In the meanwhile, the energy band gap for the deposited films was found to be within the range of 2.2 and 2.4 eV, as a result of different laser energies.

Preparation and Characterization of (CO3O5, Fe2O3: Sn) Nanocomposite for Sensitize Photoelectrodes

2021 ◽  
Vol 1039 ◽  
pp. 326-331
Author(s):  
Haleemah J. Mohammed
Keyword(s):  
Laser Pulse ◽  
Raw Materials ◽  
Second Step ◽  
Electrolysis Cell ◽  
X Ray Diffraction ◽  
Yag Laser ◽  
X Ray ◽  
Atomic Force ◽  
Electrochemical Parameters

Preparation of nanocomposite ( CO3O5,Fe2O3: Sn ) was chemically held from its raw materials as a first step of this research in order to manufacture photoelectrode , this nanocomposite was deposited on substrate glass using spraying technique and heat treatment by Nd: YAG laser pulse (LPD) . Experiments were conducted to study the surface topography of the nanocompound by (AFM) to determine the roughness of the prepared electrode, In addition, the structure characteristics were studied using the x-ray diffraction (XRD) to determine the main phase. The second step of this research was designing a glass electrolysis cell containing our nanoelectrode and producing hydrogen. Finally the electrochemical parameters of the designed cell were studied Key words: nanocomposite (CO3O5,Fe2O3:Sn), Nd: YAG laser pulse (LPD) , Photoelectrodes; atomic force microscope.

scholarly journals Advanced instrumentation for spectral and spatial investigations of high-order laser harmonics

2001 ◽  
Vol 19 (2) ◽  
pp. 201-204
Author(s):  
LUCA POLETTO ◽  
GIUSEPPE TONDELLO ◽  
PAOLO VILLORESI
Keyword(s):  
Laser Pulse ◽  
Femtosecond Laser ◽  
Femtosecond Laser Pulse ◽  
Grazing Incidence ◽  
High Order ◽  
Gas Jet ◽  
Generation Process ◽  
X Ray ◽  
Flat Field

We report on the design and characterization of a grazing-incidence flat-field spectrograph that allows simultaneously the measurement of spectrum, beam divergence, and absolute flux of EUV and soft X-ray radiation for a beam of high-order laser harmonics generated by the interaction between an ultrashort femtosecond laser pulse and a gas jet. The instrument seems a very powerful tool for the understanding of the generation process.

scholarly journals Clean source of soft X-ray radiation formed in supersonic Ar gas jets by high-contrast femtosecond laser pulses of relativistic intensity

2020 ◽  
Vol 8 ◽  
Author(s):  
Maria Alkhimova ◽  
Sergey Ryazantsev ◽  
Igor Skobelev ◽  
Alexey Boldarev ◽  
Jie Feng ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Femtosecond Laser ◽  
Argon Plasma ◽  
Plasma Source ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Average Charge ◽  
High Contrast ◽  
X Ray ◽  
Gas Jets

In this work, we optimized a clean, versatile, compact source of soft X-ray radiation $(E_{\text{x}\text{-}\text{ray}}\sim 3~\text{keV})$ with an yield per shot up to $7\times 10^{11}~\text{photons}/\text{shot}$ in a plasma generated by the interaction of high-contrast femtosecond laser pulses of relativistic intensity $(I_{\text{las}}\sim 10^{18}{-}10^{19}~\text{W}/\text{cm}^{2})$ with supersonic argon gas jets. Using high-resolution X-ray spectroscopy approaches, the dependence of main characteristics (temperature, density and ionization composition) and the emission efficiency of the X-ray source on laser pulse parameters and properties of the gas medium was studied. The optimal conditions, when the X-ray photon yield reached a maximum value, have been found when the argon plasma has an electron temperature of $T_{\text{e}}\sim 185~\text{eV}$ , an electron density of $N_{\text{e}}\sim 7\times 10^{20}~\text{cm}^{-3}$ and an average charge of $Z\sim 14$ . In such a plasma, a coefficient of conversion to soft X-ray radiation with energies $E_{\text{x}\text{-}\text{ray}}\sim 3.1\;(\pm 0.2)~\text{keV}$ reaches $8.57\times 10^{-5}$ , and no processes leading to the acceleration of electrons to MeV energies occur. It was found that the efficiency of the X-ray emission of this plasma source is mainly determined by the focusing geometry. We confirmed experimentally that the angular distribution of the X-ray radiation is isotropic, and its intensity linearly depends on the energy of the laser pulse, which was varied in the range of 50–280 mJ. We also found that the yield of X-ray photons can be notably increased by, for example, choosing the optimal laser pulse duration and the inlet pressure of the gas jet.

scholarly journals Spatial and temporal characteristics of X-ray emission from hot plasma driven by a relativistic femtosecond laser pulse

2009 ◽  
Vol 27 (1) ◽  
pp. 19-26 ◽  
Author(s):  
W. Hong ◽  
Y. He ◽  
T. Wen ◽  
H. Du ◽  
J. Teng ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Laser Intensity ◽  
Laser Fusion ◽  
X Rays ◽  
X Ray ◽  
Hot Plasma ◽  
Laser Facility ◽  
Jet Structure ◽  
Spatial And Temporal Characteristics

AbstractWe present the temporal and spatial characterization of X-ray sources (at ~1 keV) driven by a 200 TW, 30 fs, 800 nm laser pulse on SILEX-I laser facility at Research Center of Laser Fusion. For laser copper foil interaction with laser intensity between 6 × 1018 W/cm2and 3 × 1019 W/cm2, the X-ray images show cone-like jet structures. While the yield of X-rays is strongly dependent on the laser intensity, the plasma expansion length is weakly dependent on the laser intensity, and the open angle of the cone-like jet is not correlated to the laser intensity. The formation of the jet structure is attributed to the plasma transverse confine by the self-induced quasi-static magnetic field. An X-ray pedestal 4 ns preceding the main pulse was observed. The correlation between X-ray pedestal and collimated proton beam generation was found.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

Digital x-ray mapping of nanometer-size supported bimetallic catalysts

1988 ◽  
Vol 46 ◽  
pp. 530-531
Author(s):  
L. T. Germinario
Keyword(s):  
Background Radiation ◽  
Metal Cluster ◽  
Single Element ◽  
Beam Diameter ◽  
X Rays ◽  
X Ray ◽  
Major Interest ◽  
Induced Changes

Understanding the role of metal cluster composition in determining catalytic selectivity and activity is of major interest in heterogeneous catalysis. The electron microscope is well established as a powerful tool for ultrastructural and compositional characterization of support and catalyst. Because the spatial resolution of x-ray microanalysis is defined by the smallest beam diameter into which the required number of electrons can be focused, the dedicated STEM with FEG is the instrument of choice. The main sources of errors in energy dispersive x-ray analysis (EDS) are: (1) beam-induced changes in specimen composition, (2) specimen drift, (3) instrumental factors which produce background radiation, and (4) basic statistical limitations which result in the detection of a finite number of x-ray photons. Digital beam techniques have been described for supported single-element metal clusters with spatial resolutions of about 10 nm. However, the detection of spurious characteristic x-rays away from catalyst particles produced images requiring several image processing steps.

Plant Pathology Diagnosed by X-Ray Microanalysis

1987 ◽  
Vol 45 ◽  
pp. 974-975
Author(s):  
J. H. Resau ◽  
N. Howell ◽  
S. H. Chang
Keyword(s):  
Electron Microscopy ◽  
Plant Pathology ◽  
Biochemical Characterization ◽  
Nutrient Deficiency ◽  
Green Leaf ◽  
Parasitic Infestation ◽  
X Ray

Spinach grown in Texas developed “yellow spotting” on the peripheral portions of the leaves. The exact cause of the discoloration could not be determined as there was no evidence of viral or parasitic infestation of the plants and biochemical characterization of the plants did not indicate any significant differences between the yellow and green leaf portions of the spinach. The present study was undertaken using electron microscopy (EM) to determine if a micro-nutrient deficiency was the cause for the discoloration.Green leaf spinach was collected from the field and sent by express mail to the EM laboratory. The yellow and equivalent green portions of the leaves were isolated and dried in a Denton evaporator at 10-5 Torr for 24 hrs. The leaf specimens were then examined using a JEOL 100 CX analytical microscope. TEM specimens were prepared according to the methods of Trump et al.

EXELFS Studies of Carbon Fibers

1990 ◽  
Vol 48 (2) ◽  
pp. 72-73
Author(s):  
V. Serin ◽  
K. Hssein ◽  
G. Zanchi ◽  
J. Sévely
Keyword(s):  
Carbon Fibers ◽  
Energy Analysis ◽  
Electron Excitation ◽  
Complex Structures ◽  
High Modulus ◽  
Promising Technique ◽  
X Ray ◽  
Fine Structures ◽  
X Ray Absorption

The present developments of electron energy analysis in the microscopes by E.E.L.S. allow an accurate recording of the spectra and of their different complex structures associated with the inner shell electron excitation by the incident electrons (1). Among these structures, the Extended Energy Loss Fine Structures (EXELFS) are of particular interest. They are equivalent to the well known EXAFS oscillations in X-ray absorption spectroscopy. Due to the EELS characteristic, the Fourier analysis of EXELFS oscillations appears as a promising technique for the characterization of composite materials, the major constituents of which are low Z elements. Using EXELFS, we have developed a microstructural study of carbon fibers. This analysis concerns the carbon K edge, which appears in the spectra at 285 eV. The purpose of the paper is to compare the local short range order, determined by this way in the case of Courtauld HTS and P100 ex-polyacrylonitrile carbon fibers, which are high tensile strength (HTS) and high modulus (HM) fibers respectively.

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