Studies of K‐ and L‐shell x‐ray emission from laser plasmas for use as a high‐energy backlighter (abstract)

1990 ◽  
Vol 61 (10) ◽  
pp. 2816-2816
Author(s):  
J. D. Molitoris ◽  
G. M. Shimkaveg ◽  
C. J. Keane ◽  
A. R. Fry ◽  
D. J. Fields ◽  
...  
Keyword(s):  
High Energy ◽  
X Ray ◽  
Laser Plasmas

scholarly journals X-ray emission produced by hot electrons from fs-laser produced plasma— diagnostic and application

1999 ◽  
Vol 17 (4) ◽  
pp. 671-679 ◽  
Author(s):  
I. USCHMANN ◽  
P. GIBBON ◽  
D. KLÖPFEL ◽  
T. FEURER ◽  
E. FÖRSTER ◽  
...  
Keyword(s):  
High Energy ◽  
Hot Electrons ◽  
Emission Region ◽  
Single Shot ◽  
X Rays ◽  
Plasma Diagnostic ◽  
Strong Laser Field ◽  
X Ray ◽  
Laser Plasmas ◽  
Fs Laser

High intensity fs-laser pulses can deliver focused intensities in the region of 1016–1019 W/cm2. If the laser pulse is focused onto a solid or gaseous material, a plasma is created. The electrons, as well as the ions are accelerated in the strong laser field up to energies in the range of keV to several MeV. The interaction of the high energy particles with cold material, that is, the solid target yield of intense X-ray emission, K-shell—as well as bremsstrahlung-radiation. The K-shell emission from layered targets is a useful indicator of the production efficiency, energy distribution, and transport of hot electrons produced in fs-laser plasmas. For the diagnosis of laser plasma interaction and its application as an intense X-ray source, the spatial, temporal and spectral distribution of K-shell X rays is of fundamental importance. Focusing crystal spectrographs can be used to obtain a single shot X-ray spectra of laser plasmas produced by table top fs-lasers. With a spatial- and spectral-focusing spectrograph based on a toroidally bent crystal, the emission region of the hot plasma and Kα-radiation can be determined. Recording the spectra online by a frontside illuminated charge-coupled device (CCD) allows alignment of the crystal spectrograph, as well as the laser beam focusing leading to different X-ray source sizes. Using a controlled fs-prepulse, an increase in Kα radiation could be observed with the diagnostic.Measurements of calibrated high resolution spectra are compared with particle-in-cell (PIC) calculations of the laser absorption and hot electron production postprocessed by a Monte–Carlo (MC) transport model of electron stopping and Kα X-ray generation.

Diagnostics of Gold Laser Plasmas

1988 ◽  
Vol 102 ◽  
pp. 357-360
Author(s):  
J.C. Gauthier ◽  
J.P. Geindre ◽  
P. Monier ◽  
C. Chenais-Popovics ◽  
N. Tragin ◽  
...  
Keyword(s):  
Experimental Results ◽  
Pure Gold ◽  
Electronic Temperature ◽  
X Ray ◽  
Laser Plasmas ◽  
Collisional Radiative Model ◽  
Radiative Model

AbstractIn order to achieve a nickel-like X ray laser scheme we need a tool to determine the parameters which characterise the high-Z plasma. The aim of this work is to study gold laser plasmas and to compare experimental results to a collisional-radiative model which describes nickel-like ions. The electronic temperature and density are measured by the emission of an aluminium tracer. They are compared to the predictions of the nickel-like model for pure gold. The results show that the density and temperature can be estimated in a pure gold plasma.

High-purity Ge x-ray detectors: Sensitivity factors and usefulness

1990 ◽  
Vol 48 (2) ◽  
pp. 548-548
Author(s):  
E. B. Steel
Keyword(s):  
High Purity ◽  
High Energy ◽  
Quantitative Chemical Analysis ◽  
Detector Performance ◽  
X Ray ◽  
Detector Sensitivity ◽  
Specimen Holder ◽  
Many Instruments ◽  
Charge Resolution ◽  
Sensitivity Factors

High Purity Germanium (HPGe) x-ray detectors are now commercially available for the analytical electron microscope (AEM). The detectors have superior efficiency at high x-ray energies and superior resolution compared to traditional lithium-drifted silicon [Si(Li)] detectors. However, just as for the Si(Li), the use of the HPGe detectors requires the determination of sensitivity factors for the quantitative chemical analysis of specimens in the AEM. Detector performance, including incomplete charge, resolution, and durability has been compared to a first generation detector. Sensitivity factors for many elements with atomic numbers 10 through 92 have been determined at 100, 200, and 300 keV. This data is compared to Si(Li) detector sensitivity factors.The overall sensitivity and utility of high energy K-lines are reviewed and discussed. Many instruments have one or more high energy K-line backgrounds that will affect specific analytes. One detector-instrument-specimen holder combination had a consistent Pb K-line background while another had a W K-line background.

Designing high-resolution slow scan CCD-based TEM camera systems

1992 ◽  
Vol 50 (2) ◽  
pp. 946-947
Author(s):  
James F. Mancuso ◽  
William B. Maxwell ◽  
Russell E. Camp ◽  
Mark H. Ellisman
Keyword(s):  
Fiber Optics ◽  
Ccd Camera ◽  
High Energy ◽  
Phosphor Layer ◽  
X Ray ◽  
Light Production ◽  
Camera Systems ◽  
X Ray Imaging ◽  
Electron Image ◽  
Scintillating Fiber

The imaging requirements for 1000 line CCD camera systems include resolution, sensitivity, and field of view. In electronic camera systems these characteristics are determined primarily by the performance of the electro-optic interface. This component converts the electron image into a light image which is ultimately received by a camera sensor.Light production in the interface occurs when high energy electrons strike a phosphor or scintillator. Resolution is limited by electron scattering and absorption. For a constant resolution, more energy deposition occurs in denser phosphors (Figure 1). In this respect, high density x-ray phosphors such as Gd2O2S are better than ZnS based cathode ray tube phosphors. Scintillating fiber optics can be used instead of a discrete phosphor layer. The resolution of scintillating fiber optics that are used in x-ray imaging exceed 20 1p/mm and can be made very large. An example of a digital TEM image using a scintillating fiber optic plate is shown in Figure 2.

The Basic Physical Principles of Ion, Electron, and X-Ray Detectors and Their Application to Microanalysis

1985 ◽  
Vol 43 ◽  
pp. 154-157
Author(s):  
A.J. Tousimis
Keyword(s):  
Ion Beam ◽  
Depth Resolution ◽  
Sample Surface ◽  
High Energy ◽  
X Rays ◽  
X Ray ◽  
Electrons And Ions ◽  
Spatial Depth ◽  
Minimum Surface Area ◽  
Physical Principles

An integral and of prime importance of any microtopography and microanalysis instrument system is its electron, x-ray and ion detector(s). The resolution and sensitivity of the electron microscope (TEM, SEM, STEM) and microanalyzers (SIMS and electron probe x-ray microanalyzers) are closely related to those of the sensing and recording devices incorporated with them.Table I lists characteristic sensitivities, minimum surface area and depth analyzed by various methods. Smaller ion, electron and x-ray beam diameters than those listed, are possible with currently available electromagnetic or electrostatic columns. Therefore, improvements in sensitivity and spatial/depth resolution of microanalysis will follow that of the detectors. In most of these methods, the sample surface is subjected to a stationary, line or raster scanning photon, electron or ion beam. The resultant radiation: photons (low energy) or high energy (x-rays), electrons and ions are detected and analyzed.

Utilisation of High-Energy Heat Sources in Magnesium Alloy Surface Layer Treatment

2013 ◽  
Vol 58 (2) ◽  
pp. 619-624 ◽  
Author(s):  
M. Szafarska ◽  
J. Iwaszko ◽  
K. Kudła ◽  
I. Łegowik
Keyword(s):  
Surface Layer ◽  
Magnesium Alloy ◽  
Physicochemical Properties ◽  
Treatment Effectiveness ◽  
High Energy ◽  
Alloy Surface ◽  
Heat Sources ◽  
X Ray ◽  
Additional Equipment ◽  
Alloy Surface Layer

The main aim of the study was the evaluation of magnesium alloy surface treatment effectiveness using high-energy heat sources, i.e. a Yb-YAG Disk Laser and the GTAW method. The AZ91 and AM60 commercial magnesium alloys were subject to surface layer modification. Because of the physicochemical properties of the materials studied in case of the GTAW method, it was necessary to provide the welding stand with additional equipment. A novel two-torch set with torches operating in tandem was developed within the experiment. The effectiveness of specimen remelting using a laser and the GTAW method was verified based on macro- and microscopic examinations as well as in X-ray phase analysis and hardness measurements. In addition, the remelting parameters were optimised. The proposed treatment methodology enabled the achieving of the intended result and effective modification of a magnesium alloy surface layer.

Mesoscale structural characterization within bulk materials by high-energy X-ray microdiffraction

AIAA Journal ◽  
2001 ◽  
Vol 39 ◽  
pp. 919-923
Author(s):  
U. Lienert ◽  
H. F. Poulsen ◽  
A. Kvick
Keyword(s):  
Structural Characterization ◽  
High Energy ◽  
Bulk Materials ◽  
X Ray

Characterizations of Synthetic 8mol% YSZ with Comparison to 3mol %YSZ for HT-SOFC

2020 ◽  
Vol 38 (4A) ◽  
pp. 491-500
Author(s):  
Abeer F. Al-Attar ◽  
Saad B. H. Farid ◽  
Fadhil A. Hashim
Keyword(s):  
Ionic Conductivity ◽  
Electrochemical Impedance ◽  
Structural Information ◽  
Impedance Analysis ◽  
High Energy ◽  
Yttria Stabilized Zirconia ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
Powder Morphology ◽  
X Ray

In this work, Yttria (Y2O3) was successfully doped into tetragonal 3mol% yttria stabilized Zirconia (3YSZ) by high energy-mechanical milling to synthesize 8mol% yttria stabilized Zirconia (8YSZ) used as an electrolyte for high temperature solid oxide fuel cells (HT-SOFC). This work aims to evaluate the densification and ionic conductivity of the sintered electrolytes at 1650°C. The bulk density was measured according to ASTM C373-17. The powder morphology and the microstructure of the sintered electrolytes were analyzed via Field Emission Scanning Electron Microscopy (FESEM). The chemical analysis was obtained with Energy-dispersive X-ray spectroscopy (EDS). Also, X-ray diffraction (XRD) was used to obtain structural information of the starting materials and the sintered electrolytes. The ionic conductivity was obtained through electrochemical impedance spectroscopy (EIS) in the air as a function of temperatures at a frequency range of 100(mHz)-100(kHz). It is found that the 3YSZ has a higher density than the 8YSZ. The impedance analysis showed that the ionic conductivity of the prepared 8YSZ at 800°C is0.906 (S.cm) and it was 0.214(S.cm) of the 3YSZ. Besides, 8YSZ has a lower activation energy 0.774(eV) than that of the 3YSZ 0.901(eV). Thus, the prepared 8YSZ can be nominated as an electrolyte for the HT-SOFC.

HIGH ENERGY SYNCHROTRON X-RAY MICROSPECTROSCOPY FOR GEOCHEMICAL CHARACTERIZATION OF TERRESTRIAL AND EXTRATERRESTRIAL SAMPLES

2016 ◽  
Author(s):  
Antonio Lanzirotti ◽  
◽  
Stephen R. Sutton ◽  
Matt Newville ◽  
Jeffrey P. Fitts ◽  
...  
Keyword(s):  
High Energy ◽  
Geochemical Characterization ◽  
X Ray

scholarly journals Deadtime calculation method of the High Energy X-ray telescope (HE) onboard the Insight-HXMT satellite

2020 ◽  
Vol 26 ◽  
pp. 58-64 ◽  
Author(s):  
S. Xiao ◽  
S.L. Xiong ◽  
C.Z. Liu ◽  
X.B. Li ◽  
S.N. Zhang ◽  
...  
Keyword(s):  
Calculation Method ◽  
High Energy ◽  
X Ray
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