scholarly journals Hard x-ray transmission curved crystal spectrometers (10–100 keV) for laser fusion experiments at the ShenGuang-III laser facility

2016 ◽  
Vol 4 ◽  
Author(s):  
Ming-hai Yu ◽  
Guang-yue Hu ◽  
Ning An ◽  
Feng Qian ◽  
Yu-chi Wu ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Optical Design ◽  
Experimental Results ◽  
Laser Fusion ◽  
Recording Medium ◽  
High Quality ◽  
X Ray ◽  
Laser Facility ◽  
Working Distance ◽  
Spectral Ranges

Two transmission curved crystal spectrometers are designed to measure the hard x-ray emission in the laser fusion experiment of Compton radiography of implosion target on ShenGuang-III laser facility in China. Cylindrically curved ${\it\alpha}$ -quartz (10–11) crystals with curvature radii of 150 and 300 mm are used to cover spectral ranges of 10–56 and 17–100 keV, respectively. The distance between the crystal and the x-ray source can be changed over a broad distance from 200 to 1500 mm. The optical design, including the integral reflectivity of the curved crystal, the sensitivity, and the spectral resolution of the spectrometers, is discussed. We also provide mechanic design details and experimental results using a Mo anode x-ray source. High-quality spectra were obtained. We confirmed that the spectral resolution can be improved by increasing the working distance, which is the distance between the recording medium and the Rowland circle.

Theory & Performance of Holographically-Formed Stigmatic X-Ray Gratings

1975 ◽  
Vol 19 ◽  
pp. 643-656
Author(s):  
R. J. Speer
Keyword(s):  
Fringe Pattern ◽  
Optical Design ◽  
Grazing Incidence ◽  
Laser Fusion ◽  
Molecular Chemistry ◽  
X Ray ◽  
First Order ◽  
Imaging Theory ◽  
Reflection Grating ◽  
Aberration Corrected

Holographically-formed X-ray reflection grating scan now be constructed with competitive groove efficiency to classically ruled types, down to a short wavelength diffracting limit of several angstroms.The gratings can be generated on any surface capable of intersecting the interference fringe pattern without shadowing. This fact alone brings several new X-ray optical design possibilities within reach, for example, by combining plane construction waves with steep aspheric substrates. The first order imaging theory of the grazing incidence mounting is discussed and compared to measured performance for aberration corrected stigmatic types.A new 5 meter spectrograph has also been constructed with applications in molecular chemistry, laser fusion research and synchro tronspectroscopy. The unit is available with fully prefocussed holographic and classical X-ray grating optics, and uses the precision miniature camera principle of fully interchangeable lenses, but applied, in this case to the entrance slit, grating and detector modules.

scholarly journals X-ray microscopy of laser-produced plasmas with the use of bent crystals

1991 ◽  
Vol 9 (1) ◽  
pp. 135-148 ◽  
Author(s):  
E. Förster ◽  
K. Gäbel ◽  
I. Uschmann
Keyword(s):  
Dynamical Theory ◽  
High Luminosity ◽  
Spectral Window ◽  
X Ray ◽  
Lyman Alpha ◽  
Laser Facility ◽  
Spectral Ranges ◽  
Bent Crystals ◽  
Intercombination Line

X-ray spectroscopical and microscopical methods are used for the determination of the spectral and spatial distribution of X-ray intensity of laser-produced plasmas. The use of Bragg reflections of two-dimensionally bent crystals enables the X-ray microscopical imaging in narrow spectral ranges (Δλ/λ = 10−4 to 10−2) with wavelengths 0.1 nm < λ > 2.6 nm. It is possible to adapt, in the X-ray microscope, the distances, magnification, position, and width of the spectral window to the special conditions of the laser facility. Manufacturing and testing of the two-dimensionally bent crystals requires a great deal of effort. It was demonstrated that a spatial resolution of about 5 μm was achieved, and that the experimentally determined reflectivity was found to be in close agreement with the dynamical theory of X-ray interferences. Due to high luminosity of the X-ray microscope, in experiments with laser-produced plasmas it was necessary to attenuate the radiation with aperture-limiting diaphragms or filters down to 0.01–1% of the original intensity in the case of a magnification of about one. Emission of the resonance line W 1–2, the intercombination line of helium-like ions, and Lyman alpha line were imaged simultaneously with a three-channel microscope. Such images form the foundation for establishing the Ne(r), Tz(r) maps.

scholarly journals ASCA X-ray Spectra of Quiescent and Flaring Emission from AB Doradus

1995 ◽  
Vol 151 ◽  
pp. 168-169
Author(s):  
S.M. White ◽  
R. Pallavicini ◽  
J. Lim
Keyword(s):  
Spectral Resolution ◽  
Time Profile ◽  
High Spectral Resolution ◽  
High Quality ◽  
High Count ◽  
Background Spectrum ◽  
Strong Emission ◽  
X Ray ◽  
Hot Plasma ◽  
Decay Times

The Japanese satellite ASCA carries X-ray detectors which combine excellent sensitivity and high spectral resolution. We observed the young, rapidly-rotating K dwarf AB Doradus with ASCA in November 1993. The star’s X-ray flux was essentially steady for the first half of the observation, and then a series of flares occurred during the second half. The flares showed rise times of 30 minutes and decay times of several hours. The quiescent X-ray luminosity was 2 × 1030 ergs s−1 (0.5-10 keV). At the flare peaks, LX(> 0.5 keV)/Lbol = .002.AB Dor has a relatively high count rate in the ASCA data and we can obtain high-quality spectra for different periods of the light curve. In Fig. 1 we present spectra corresponding to the period of quiescence, the rising phase and peak of each of the three flares combined, and the decay periods of each of the flares combined. The rise/peak curve (upper) has been multiplied by 2 for purposes of display. We have subtracted the quiescent spectrum from the flare spectra (i.e., used it as a background spectrum) for this display and subsequent analysis.The detailed differences between these spectra display the importance of the high spectral resolution provided by ASCA. One important difference, not readily evident in this figure, is the Fe K line complex at 6.4-6.7 keV. This line, a diagnostic of hot plasma, is strong in the rise/peak spectrum, moderate in the decay spectrum and weak in the quiescent spectrum. A time profile of the counts in this energy range shows little significant emission during the quiescent periods but strong emission at the flare peaks.

scholarly journals Characterization of laser-driven Radiative shock of Astrophysical interests

2015 ◽  
Vol 11 (A29A) ◽  
Author(s):  
U. Chaulagain ◽  
C. Stehlé ◽  
J. Larour ◽  
M. Kozlová ◽  
F. Suzuki-Vidal ◽  
...  
Keyword(s):  
Shock Waves ◽  
Shock Structure ◽  
Experimental Results ◽  
Radiative Shock ◽  
X Ray ◽  
Laser Facility ◽  
Post Shock

AbstractWe highlight the recent experimental results on laser-driven radiative shock waves of astrophysical interests using kJ PALS laser facility. The generated shock is probed instantaneously by X-ray laser (λ = 21.2 nm) showing an unambiguous shock structure that includes both the post-shock and the precursor.

Combined Microstructure X-Ray Optics; Multilayer Diffraction Gratings

1987 ◽  
Vol 103 ◽  
Author(s):  
Troy W. Barbee
Keyword(s):  
High Efficiency ◽  
Extreme Ultraviolet ◽  
Diffraction Gratings ◽  
Experimental Results ◽  
Optical Elements ◽  
Ray Optics ◽  
X Ray ◽  
Spectral Ranges

ABSTRACTMultilayers are man-made microstructures engineered to vary in depth that are now of sufficient quality to be used as x-ray, soft x-ray and extreme ultraviolet optics. Gratings are in-plane man-made microstructures which have been used as optic elements for most of this century. Joining of these two optical elements to form combined microstructure optics has the potential for greatly enhancing both the resolution and the throughput attainable in these spectral ranges. Experimental results for multilayer gratings are presented and discussed. It will be demonstrated that multilayer diffraction gratings act as x-ray prisms and are high efficiency dispersion elements.

scholarly journals Soft X-ray angle-resolved photoemission with micro-positioning techniques for metallic V2O3

2015 ◽  
Vol 22 (3) ◽  
pp. 776-780 ◽  
Author(s):  
Hidenori Fujiwara ◽  
Takayuki Kiss ◽  
Yuki K. Wakabayashi ◽  
Yoshito Nishitani ◽  
Takeo Mori ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Polar Angle ◽  
Sample Surface ◽  
Photoemission Spectroscopy ◽  
High Quality ◽  
X Ray ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Position Dependence ◽  
Working Distance ◽  
Band Mapping

Soft X-ray angle-resolved photoemission has been performed for metallic V2O3. By combining a microfocus beam (40 µm × 65 µm) and micro-positioning techniques with a long-working-distance microscope, it has been possible to observe band dispersions from tiny cleavage surfaces with a typical size of several tens of µm. The photoemission spectra show a clear position dependence, reflecting the morphology of the cleaved sample surface. By selecting high-quality flat regions on the sample surface, it has been possible to perform band mapping using both photon-energy and polar-angle dependences, opening the door to three-dimensional angle-resolved photoemission spectroscopy for typical three-dimensional correlated materials where large cleavage planes are rarely obtained.

X-ray-radiation-recording streak-camera-based technique used in experimental studies of laser fusion instabilities at ISKRA-4 laser facility

1999 ◽  
Author(s):  
Alexei V. Senik ◽  
Sergey G. Garanin ◽  
Valeri P. Lazarchuk ◽  
Vasili M. Murugov ◽  
Sergei I. Petrov
Keyword(s):  
Streak Camera ◽  
Experimental Studies ◽  
Laser Fusion ◽  
X Ray ◽  
Laser Facility

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.

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.

Axial Observation of X-Ray Spectra from a Beam-Foil Source

1988 ◽  
Vol 102 ◽  
pp. 339-342
Author(s):  
J.M. Laming ◽  
J.D. Silver ◽  
R. Barnsley ◽  
J. Dunn ◽  
K.D. Evans ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Heavy Ion ◽  
Ion Beams ◽  
Beam Axis ◽  
Doppler Broadening ◽  
X Ray ◽  
Beam Foil

AbstractNew observations of x-ray spectra from foil-excited heavy ion beams are reported. By observing the target in a direction along the beam axis, an improvement in spectral resolution, δλ/λ, by about a factor of two is achieved, due to the reduced Doppler broadening in this geometry.

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