Doppler Shift and Broadening of K- and L-Shell x-ray Spectral Lines in Imploded Wire-Arrays on MAGPIE and COBRA Pulsers

Author(s):  
Sergey A. Pikuz ◽  
Kate S. Bell ◽  
Tatiana A. Shelkovenko ◽  
Jonathan D. Douglass ◽  
Ryan D. McBride ◽  
...  
Author(s):  
Martin Peckerar ◽  
Anastasios Tousimis

Solid state x-ray sensing systems have been used for many years in conjunction with scanning and transmission electron microscopes. Such systems conveniently provide users with elemental area maps and quantitative chemical analyses of samples. Improvements on these tools are currently sought in the following areas: sensitivity at longer and shorter x-ray wavelengths and minimization of noise-broadening of spectral lines. In this paper, we review basic limitations and recent advances in each of these areas. Throughout the review, we emphasize the systems nature of the problem. That is. limitations exist not only in the sensor elements but also in the preamplifier/amplifier chain and in the interfaces between these components.Solid state x-ray sensors usually function by way of incident photons creating electron-hole pairs in semiconductor material. This radiation-produced mobile charge is swept into external circuitry by electric fields in the semiconductor bulk.


2015 ◽  
Vol 22 (11) ◽  
pp. 112702 ◽  
Author(s):  
A. A. Anderson ◽  
V. V. Ivanov ◽  
A. L. Astanovitskiy ◽  
D. Papp ◽  
P. P. Wiewior ◽  
...  
Keyword(s):  
X Ray ◽  

2008 ◽  
Vol 63 (1-2) ◽  
pp. 35-41 ◽  
Author(s):  
Friedwardt Winterberg

Dense matter, if put under high pressure, can undergo a transformation from an atomic to a molecular configuration, where the electron orbits go into lower energy levels. If the rise in pressure is very sudden, for example by a strong shock wave, the electrons change their orbits rapidly under the emission of photons, which for more than 100 Mbar can reach keV energies. With the opacity of dense matter going in proportion to the density, the photons can be efficiently released from the surface of the compressed matter by a rarefaction wave. The so produced X-ray photons can be used for the fast ignition of a thermonuclear target.The proposed mechanism may be also responsible for the large keV X-ray bursts observed in exploding wire arrays, which can not be explained by conversion of kinetic into thermal energy.


2010 ◽  
Vol 244 (3) ◽  
pp. 032031 ◽  
Author(s):  
A S Safronova ◽  
V L Kantsyrev ◽  
A A Esaulov ◽  
N D Ouart ◽  
V Shlyaptseva ◽  
...  
Keyword(s):  
X Ray ◽  

2010 ◽  
Vol 37 (3) ◽  
pp. 685-688 ◽  
Author(s):  
王洪建 Wang Hongjian ◽  
肖沙里 Xiao Shali ◽  
施军 Shi Jun ◽  
黄显宾 Huang Xianbin ◽  
蔡红春 Cai Hongchun ◽  
...  

1991 ◽  
Vol 9 (2) ◽  
pp. 501-515 ◽  
Author(s):  
P. Glas ◽  
M. Schnürer

We investigated the case where two laser-produced plasmas collide nearly head on. Special attention was devoted to the fundamentals necessary to realize a coherent X-ray source. A gas-dynamic computational analysis was performed to understand the evolution of the density, the temperature, and the velocity of merging plasmas. The spatial intensity distribution of selected spectral lines reveals that the interaction of plasmas of different nuclear charge and charge state is not strictly collision dominated. Using spectral line intensity ratios, we determined electron temperatures and electron number densities, as well as the intensity inversion on the 4–1 to 3–1 resonance transitions of [He]-like Al. Inversion occurs in the vicinity of the targets if identical materials are used (Al–Al) and is possibly indicated in the interaction zone for different ones (Al–Cu), too. The inversion factors (and the gain coefficient) for the 4–3 transition of [He]-like Al at about 130 Å were estimated.


1972 ◽  
Vol 16 ◽  
pp. 251-259 ◽  
Author(s):  
K. Das Gupta ◽  
Herbert Welch ◽  
P.F. Gott ◽  
John F. Priest ◽  
Sunny Cheng ◽  
...  

AbstractThree novel methods of x-ray spectrometry have been developed in recent years at Texas Tech University. These are:1. Three crystal spectrometer2. Two curved crystal spectrometer3. Spherically bent crystal spectrometer.In this paper the new design features, and experimental results will be discussed to indicate the usefulness of the new instruments. The three crystal spectrometer is a modified two crystal instrument. A third crystal is used to analyze the output of the two crystal spectrometer. The first two crystals are operated as a standard two crystal spectrometer. The third crystal is swept through the spectrum transmitted by the first two crystals for each setting of the first two crystals. The peak intensity of the third crystal sweep corresponds to the energy setting of the two crystal spectrometer, and is the intensity used to plot the spectral lines. The two curved crystal spectrometer utilizes two transmission spectrographs with radii having a 2:1 ratio in series, the crystal with the smaller radius being set so that its focal point falls on the Rowland circle of the larger radius crystal, This instrument has a very low background intensity and is suitable for precision scattering and diffraetion work. The spherically bent crystal spectrometer makes use of high light gathering power and high orders of reflection to allow high resolution studies of weak spectral lines. It also has the advantage of ease of alignment and operation.


2015 ◽  
Vol 11 (A29A) ◽  
pp. 295-296
Author(s):  
Natalie Hell ◽  
Greg V. Brown ◽  
Jörn Wilms ◽  
Peter Beiersdorfer ◽  
Richard L. Kelley ◽  
...  

AbstractWith the large improvement in effective area of Astro-H's micro-calorimeter soft X-ray spectrometer (SXS) over grating spectrometers, high-resolution X-ray spectroscopy with good signal to noise will become more commonly available, also for faint and extended sources. This will result in a range of spectral lines being resolved for the first time in celestial sources, especially in the Fe region. However, a large number of X-ray line energies in the atomic databases are known to a lesser accuracy than that expected for Astro-H/SXS, or have no known uncertainty at all. To benchmark the available calculations, we have therefore started to measure reference energies of K-shell transition in L-shell ions for astrophysically relevant elements in the range 11≤ Z ≤ 28 (Na to Ni), using the Lawrence Livermore National Laboratory's EBIT-I electron beam ion trap coupled with the NASA/GSFC EBIT calorimeter spectrometer (ECS). The ECS has a resolution of ~5 e V, i.e., similar to Astro-H/SXS and Chandra/HETG. A comparison to crystal spectra of lower charge states of sulfur with ~0.6 e V resolution shows that the analysis of spectra taken at ECS resolution allows to determine the transition energies of the strongest components.


1985 ◽  
Vol 19 (1) ◽  
pp. 64-68
Author(s):  
M. E. Machado

The ongoing research carried out by the solar community has been reported in the proceedings of several recent symposia, seminars and workshops, as well as in scientific journals (Kane et al. 1983, Švestka et al. 1982a, Shea et al. 1984, Kundu S Woodgate 1984, Simon 1984). We summarize here some of the novel results with reference to flare research as far as SMM data analysis is concerned. Understanding of impulsive phase phenomena was one of the primary goals of the SMM. The early reports from the analysis of the first ever obtained high-resolution images in the <30 keV energy range stressed the fact that some flares showed hard x-ray (HXR) bright sources at the feet of coronal loops (Hoyng et al. 1981a, b, Machado et al. 1982, Duijveman et al. 1982), the so-called HXR “footpoints,” favoring the thick-target beam mechanism for the production of HXRs, and indicating acceleration efficiencies >20% during the early impulsive phase. This phenomenon was shown to be accompanied by soft x-ray (SXR) line broadening, indicative of strong turbulence, and the immediate appearance of blue shifted spectral lines, which shows that plasma heated to >10-1 K rises from the footpoints of loops with velocities to 300 km s-1 (Antonucci et al. 1982, Antonucci et al. 1984a). This result provides a strong indication of the chromospheric evaporation phenomenon, which has been confirmed in analyses of combined SXR and Ha observations (Acton et al. 1982, Gunkler et al. 1984).


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