Study of the effect of opacity on the solar coronal X-ray Mg XII 0.842 nm spectral lines

2014 ◽  
Vol 65 (4) ◽  
pp. 476-479
Author(s):  
Xiping Hao ◽  
Jian He ◽  
Huihui Liu
Keyword(s):  
Spectral Lines ◽  
X Ray ◽  
Solar Coronal

Investigating the Effect of Opacity in Soft X‐Ray Spectral Lines Emitted by Solar Coronal Active Regions

1997 ◽  
Vol 477 (1) ◽  
pp. 509-515 ◽  
Author(s):  
J. T. Schmelz ◽  
J. L. R. Saba ◽  
J. C. Chauvin ◽  
K. T. Strong
Keyword(s):  
Active Regions ◽  
Spectral Lines ◽  
X Ray ◽  
Solar Coronal

Current Status of Solid-State X-Ray Systems

1985 ◽  
Vol 43 ◽  
pp. 158-161
Author(s):  
Martin Peckerar ◽  
Anastasios Tousimis
Keyword(s):  
Solid State ◽  
Electric Fields ◽  
Spectral Lines ◽  
Current Status ◽  
Mobile Charge ◽  
Electron Hole ◽  
X Ray ◽  
Sensing Systems ◽  
Transmission Electron ◽  
Electron Microscopes

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.

scholarly journals Self-organized braiding in solar coronal loops

2015 ◽  
Vol 81 (4) ◽  
Author(s):  
M. A. Berger ◽  
M. Asgari-Targhi ◽  
E. E. DeLuca
Keyword(s):  
Coronal Loops ◽  
Frequency Distributions ◽  
Fire Model ◽  
X Ray ◽  
Self Organized ◽  
Forest Fire Model ◽  
Distribution Laws ◽  
Field Lines ◽  
Power Law Distributions ◽  
Solar Coronal

AbstractIn this paper, we investigate the evolution of braided solar coronal loops. We assume that coronal loops consist of several internal strands which twist and braid about each other. Reconnection between the strands leads to small flares and heating of the loop to x-ray temperatures. Using a method of generating and releasing braid structure similar to a forest fire model, we show that the reconnected field lines evolve to a self-organised critical state. In this state, the frequency distributions of coherent braid sequences as well as flare energies follow power law distributions. We demonstrate how the presence of net helicity in the loop alters the distribution laws.

scholarly journals Investigations concerning plasma parameters and population inversion in laser-produced counterstreaming plasmas

1991 ◽  
Vol 9 (2) ◽  
pp. 501-515 ◽  
Author(s):  
P. Glas ◽  
M. Schnürer
Keyword(s):  
Computational Analysis ◽  
Nuclear Charge ◽  
Gain Coefficient ◽  
Spectral Lines ◽  
Interaction Zone ◽  
Electron Number ◽  
Plasma Parameters ◽  
X Ray ◽  
Spatial Intensity Distribution ◽  
Resonance Transitions

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.

The solar coronal X-ray spectrum from 5.5 to 12 A

1985 ◽  
Vol 289 ◽  
pp. 849 ◽  
Author(s):  
D. L. McKenzie ◽  
P. B. Landecker ◽  
U. Feldman ◽  
G. A. Doschek
Keyword(s):  
X Ray ◽  
Solar Coronal

Some New Methods of Precision X-Ray Spectrometry

1972 ◽  
Vol 16 ◽  
pp. 251-259 ◽  
Author(s):  
K. Das Gupta ◽  
Herbert Welch ◽  
P.F. Gott ◽  
John F. Priest ◽  
Sunny Cheng ◽  
...  
Keyword(s):  
Focal Point ◽  
Spectral Lines ◽  
Background Intensity ◽  
List Type ◽  
Crystal Spectrometer ◽  
X Ray ◽  
Bent Crystal ◽  
The Third ◽  
Light Gathering Power ◽  
In Series

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.

scholarly journals A Two-sided Loop X-Ray Solar Coronal Jet Driven by a Minifilament Eruption

2019 ◽  
Vol 871 (2) ◽  
pp. 220 ◽  
Author(s):  
Alphonse C. Sterling ◽  
Louise K. Harra ◽  
Ronald L. Moore ◽  
David A. Falconer
Keyword(s):  
X Ray ◽  
Solar Coronal
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