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.

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.

Time-dependent X-ray polarization analysis for anisotropic distribution of hot electrons in ultrahigh intensity laser plasmas

2007 ◽  
Vol 3 (1-2) ◽  
pp. 131-135 ◽  
Author(s):  
T. Kai ◽  
T. Kawamura ◽  
Y. Inubushi ◽  
H. Nishimura ◽  
T. Nakamura ◽  
...  
Keyword(s):  
Time Dependent ◽  
Hot Electrons ◽  
Polarization Analysis ◽  
X Ray ◽  
Laser Plasmas ◽  
Intensity Laser

A multi-length-scale USAXS/SAXS facility: 10–50 keV small-angle X-ray scattering instrument

2013 ◽  
Vol 46 (5) ◽  
pp. 1508-1512 ◽  
Author(s):  
Byron Freelon ◽  
Kamlesh Suthar ◽  
Jan Ilavsky
Keyword(s):  
Small Angle ◽  
Soft Matter ◽  
High Energy ◽  
X Rays ◽  
X Ray ◽  
X Ray Scattering ◽  
Wide Range ◽  
And Performance ◽  
New Facility ◽  
Ray Scattering

Coupling small-angle X-ray scattering (SAXS) and ultra-small-angle X-ray scattering (USAXS) provides a powerful system of techniques for determining the structural organization of nanostructured materials that exhibit a wide range of characteristic length scales. A new facility that combines high-energy (HE) SAXS and USAXS has been developed at the Advanced Photon Source (APS). The application of X-rays across a range of energies, from 10 to 50 keV, offers opportunities to probe structural behavior at the nano- and microscale. An X-ray setup that can characterize both soft matter or hard matter and high-Zsamples in the solid or solution forms is described. Recent upgrades to the Sector 15ID beamline allow an extension of the X-ray energy range and improved beam intensity. The function and performance of the dedicated USAXS/HE-SAXS ChemMatCARS-APS facility is described.

A high-energy triple-axis X-ray diffractometer for the study of the structure of bulk crystals

2004 ◽  
Vol 37 (6) ◽  
pp. 901-910 ◽  
Author(s):  
C. Seitz ◽  
M. Weisser ◽  
M. Gomm ◽  
R. Hock ◽  
A. Magerl
Keyword(s):  
High Energy ◽  
X Rays ◽  
Bulk Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Peak Intensity ◽  
High Penetration ◽  
Massive Sample ◽  
Laue Geometry ◽  
The Ideal

A triple-axis diffractometer for high-energy X-ray diffraction is described. A 450 kV/4.5 kW stationary tungsten X-ray tube serves as the X-ray source. Normally, 220 reflections of thermally annealed Czochralski Si are employed for the monochromator and analyser. Their integrated reflectivity is about ten times higher than the ideal crystal value. With the same material as the sample, and working with the WKα line at 60 keV in symmetric Laue geometry for all axes, the full width at half-maximum (FWHM) values for the longitudinal and transversal resolution are 2.5 × 10−3and 1.1 × 10−4for ΔQ/Q, respectively, and the peak intensity for a non-dispersive setting is 3000 counts s−1. In particular, for a double-axis mode, an energy well above 100 keV from theBremsstrahlungspectrum can be used readily. High-energy X-rays are distinguished by a high penetration power and materials of several centimetre thickness can be analysed. The feasibility of performing experiments with massive sample environments is demonstrated.

Coating thickness determination in highly absorbent core–shell systems

2012 ◽  
Vol 45 (5) ◽  
pp. 906-913 ◽  
Author(s):  
Herve Palancher ◽  
Anne Bonnin ◽  
Veijo Honkimäki ◽  
Heikki Suhonen ◽  
Peter Cloetens ◽  
...  
Keyword(s):  
Coating Thickness ◽  
Protective Layer ◽  
Test Sample ◽  
High Energy ◽  
Core Shell ◽  
Single Shot ◽  
X Ray Diffraction ◽  
X Ray ◽  
Alloy Particles ◽  
Potential Applications

This article describes a single-shot methodology to derive an average coating thickness in multi-particle core–shell systems exhibiting high X-ray absorption. Powder composed of U–Mo alloy particles surrounded by a micrometre-thick UO2protective layer has been used as a test sample. Combining high-energy X-ray diffraction and laser granulometry, the average shell thickness could be accurately characterized. These results have been validated by additional measurements on single particles by two techniques: X-ray nanotomography and high-energy X-ray diffraction. The presented single-shot approach gives rise to many potential applications on core–shell systems and in particular on as-fabricated heterogeneous nuclear fuels.

scholarly journals Evaluation of the Weighted Mean X-ray Energy for an Imaging System Via Propagation-Based Phase-Contrast Imaging

2020 ◽  
Vol 6 (7) ◽  
pp. 63
Author(s):  
Maria Seifert ◽  
Mareike Weule ◽  
Silvia Cipiccia ◽  
Silja Flenner ◽  
Johannes Hagemann ◽  
...  
Keyword(s):  
Phase Contrast ◽  
Heavy Ion ◽  
High Energy ◽  
Phase Contrast Imaging ◽  
Single Shot ◽  
Contrast Imaging ◽  
Weighted Mean ◽  
X Ray ◽  
Energy Laser ◽  
High Energy Laser

For imaging events of extremely short duration, like shock waves or explosions, it is necessary to be able to image the object with a single-shot exposure. A suitable setup is given by a laser-induced X-ray source such as the one that can be found at GSI (Helmholtzzentrum für Schwerionenforschung GmbH) in Darmstadt (Society for Heavy Ion Research), Germany. There, it is possible to direct a pulse from the high-energy laser Petawatt High Energy Laser for Heavy Ion eXperiments (PHELIX) on a tungsten wire to generate a picosecond polychromatic X-ray pulse, called backlighter. For grating-based single-shot phase-contrast imaging of shock waves or exploding wires, it is important to know the weighted mean energy of the X-ray spectrum for choosing a suitable setup. In propagation-based phase-contrast imaging the knowledge of the weighted mean energy is necessary to be able to reconstruct quantitative phase images of unknown objects. Hence, we developed a method to evaluate the weighted mean energy of the X-ray backlighter spectrum using propagation-based phase-contrast images. In a first step wave-field simulations are performed to verify the results. Furthermore, our evaluation is cross-checked with monochromatic synchrotron measurements with known energy at Diamond Light Source (DLS, Didcot, UK) for proof of concepts.

scholarly journals X-ray spectra and light curves of cooling novae and a nova like

2020 ◽  
Vol 499 (2) ◽  
pp. 3006-3018
Author(s):  
Bangzheng Sun ◽  
Marina Orio ◽  
Andrej Dobrotka ◽  
Gerardo Juan Manuel Luna ◽  
Sergey Shugarov ◽  
...  
Keyword(s):  
Light Curve ◽  
Accretion Rate ◽  
High Energy ◽  
Gravitational Energy ◽  
Light Curves ◽  
Clear Correlation ◽  
X Rays ◽  
High State ◽  
X Ray ◽  
Low X

ABSTRACT We present X-ray observations of novae V2491 Cyg and KT Eri about 9 yr post-outburst of the dwarf nova and post-nova candidate EY Cyg, and of a VY Scl variable. The first three objects were observed with XMM–Newton, KT Eri also with the Chandra ACIS-S camera, V794 Aql with the Chandra ACIS-S camera and High Energy Transmission Gratings. The two recent novae, similar in outburst amplitude and light curve, appear very different at quiescence. Assuming half of the gravitational energy is irradiated in X-rays, V2491 Cyg is accreting at $\dot{m}=1.4\times 10^{-9}{\!-\!}10^{-8}\,{\rm M}_\odot \,{\rm yr}^{-1}$, while for KT Eri, $\dot{m}\lt 2\times 10^{-10}{\rm M}_\odot \,{\rm yr}$. V2491 Cyg shows signatures of a magnetized WD, specifically of an intermediate polar. A periodicity of  39 min, detected in outburst, was still measured and is likely due to WD rotation. EY Cyg is accreting at $\dot{m}\sim 1.8\times 10^{-11}{\rm M}_\odot \,{\rm yr}^{-1}$, one magnitude lower than KT Eri, consistently with its U Gem outburst behaviour and its quiescent UV flux. The X-rays are modulated with the orbital period, despite the system’s low inclination, probably due to the X-ray flux of the secondary. A period of  81 min is also detected, suggesting that it may also be an intermediate polar. V794 Aql had low X-ray luminosity during an optically high state, about the same level as in a recent optically low state. Thus, we find no clear correlation between optical and X-ray luminosity: the accretion rate seems unstable and variable. The very hard X-ray spectrum indicates a massive WD.

scholarly journals Chemical State Mapping via Soft X-rays using a Wavelength Dispersive Soft X-ray Emission Spectrometer with High Energy Resolution

2013 ◽  
Vol 19 (S2) ◽  
pp. 1258-1259 ◽  
Author(s):  
H. Takahashi ◽  
N. Handa ◽  
T. Murano ◽  
M. Terauchi ◽  
M. Koike ◽  
...  
Keyword(s):  
Energy Resolution ◽  
High Energy ◽  
Chemical State ◽  
High Energy Resolution ◽  
X Rays ◽  
X Ray

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.

scholarly journals X-Ray Evidence for the Acceleration, Containment, and Emission of High Energy Flare Particles

1974 ◽  
Vol 57 ◽  
pp. 421-422 ◽  
Author(s):  
Kenneth J. Frost
Keyword(s):  
Cosmic Ray ◽  
High Energy ◽  
Solar Observatory ◽  
Time Structure ◽  
Radio Bursts ◽  
X Rays ◽  
Thermal Component ◽  
X Ray ◽  
Type Iii ◽  
Explosive Phase

An instrument aboard the Fifth Orbiting Solar Observatory has observed hard solar X-rays from January 1969 to May 1972. A large number of X-ray bursts generated by solar cosmic ray flares have been observed. The X-ray bursts consist, in general, of two non-thermal components. The earliest occurring non-thermal component, coincident with the explosive phase, consists of a group of one to about ten X-ray bursts that are, for each burst, approximately 10 s duration and symmetrical in rise and decay. The time structure and multiplicity of these bursts is remarkably similar to that found in type III radio bursts in the meterwave band. The spectra of these bursts steepens sharply at energies greater than 100 keV indicating a limit at this energy for electron acceleration during the explosive or flash phase of the flare. For several flares these multiple X-ray bursts have occurred in coincidence with a group of type III bursts.

scholarly journals Imaging in Hard X-ray Astronomy

2003 ◽  
Vol 214 ◽  
pp. 70-83 ◽  
Author(s):  
T. P. Li
Keyword(s):  
Gamma Ray ◽  
Signal To Noise Ratio ◽  
High Energy ◽  
High Signal ◽  
Wide Field ◽  
X Rays ◽  
X Ray ◽  
Energy Gamma ◽  
High Resolution Images ◽  
Energy Processes

The energy range of hard X-rays is a key waveband to the study of high energy processes in celestial objects, but still remains poorly explored. In contrast to direct imaging methods used in the low energy X-ray and high energy gamma-ray bands, currently imaging in the hard X-ray band is mainly achieved through various modulation techniques. A new inversion technique, the direct demodulation method, has been developed since early 90s. with this technique, wide field and high resolution images can be derived from scanning data of a simple collimated detector. The feasibility of this technique has been confirmed by experiment, balloon-borne observation and analyzing simulated and real astronomical data. Based the development of methodology and instrumentation, a high energy astrophysics mission – Hard X-ray Modulation Telescope (HXMT) has been proposed and selected in China for a four-year Phase-A study. The main scientific objectives are a full-sky hard X-ray (20–200 keV) imaging survey and high signal-to-noise ratio timing studies of high energy sources.

Sign in / Sign up

Export Citation Format

Share Document