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

1975 ◽  
Vol 68 ◽  
pp. 183-183
Author(s):  
P. R. Sengupta

SummaryIt is known that the flare component of solar X-ray emission is sensitive to the level of solar activity. The location of the X-ray flaring region is not directly known but can be inferred from the location of the associated Hα flare. A detailed study of more than 4000 solar X-ray flares recorded by UI and the NRL detectors during past eight years has shown that 85% of these flares definitely occurred in the active regions. For the rest 15% no definite conclusion was possible because either Hα flare data was not available or no Hα flare was reported within ± 15 min of these X-ray flares.


2015 ◽  
Vol 11 (S320) ◽  
pp. 442-446 ◽  
Author(s):  
Janusz Sylwester ◽  
Marek Siarkowski ◽  
Jarosław Bąkała ◽  
Żaneta Szaforz ◽  
Mirosław Kowaliński ◽  
...  

AbstractChemiX is a Bragg crystal spectrometer that will fly on the two Interhelioprobe spacecraft due for launch in 2025 and 2026. The spacecraft perihelion will be only 0.3 a.u. and the orbit inclination up to 30°, and so instruments on board will have a close view of solar active regions and flares and regions near each solar pole. The ChemiX X-ray spectrometer, built by a consortium of groups led by the Space Research Centre, Polish Academy of Sciences, will fly on each of the spacecraft, and observe X-ray spectra in the 1.5 - 9 Å range. Spectral lines in this range include resonance lines of helium-like and hydrogen-like ions of elements such as Fe, Ca, Ar, S, and Si, with less abundant elements such as K and Cl represented by weaker lines which the high sensitivity of ChemiX should be able to detect. The free–free and free–bound continua should also be detected since instrumental background will be eliminated. Three of the seven channels of ChemiX will be in a “dopplerometer” arrangement by which spatial and spectral shifts present in flare impulsive stages can be disentangled.


1994 ◽  
Vol 144 ◽  
pp. 163-168 ◽  
Author(s):  
E. Hiei

AbstractSolar coronal features seen in X-ray emission change on two different timescales: a) flare loops and transient brightenings in active regions show a rapid variability, b) quiet region loops are quasi-steady and change only slowly with time. This different time behavior has been analyzed on the basis of Yohkoh SXT observations and we report here on the results from our analysis, mainly focussing on quiet loop variability.


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.


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