Results 131 to 140 of about 19,921 (169)

A multithermal analysis of solar X-ray emission

Solar Physics, 1974
The NRL SOLRAD 10 satellite carries six ionization chambers to measure solar X-radiation in the 0.5 to 60 A wavelength band. The X-ray emission spectrum in this range is determined by the derivative of the coronal emission measure (∫ Ne2dV) with respect to temperature when the thermal processes of bremsstrahlung, radiative recombination and line ...
Kenneth P. Dere, Donald M. Horan, Robert W. Kreplin   +2 more
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K? line emission during solar X-ray bursts

Solar Physics, 1973
Kα X-ray line emission from S, Ar, Ca and Fe is calculated for conditions likely to exist in solar flares. We consider both the non-thermal and thermal phases of flares as indicated by X-ray observations. Impulsive non-thermal events seen at the onset of a flare at photon energies > 20 keV generally give rise to small Kα line fluxes (
K. J. H. Phillips, W. M. Neupert
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Solar Limb Surges accompanied by X-Ray Emission

Nature, 1960
SUDDEN enhancements of atmospherics are recorded during solar flares1. The extra ionization of the lower D region at these times is brought about by X-rays emitted from the disturbed solar region2.
J. KLECZEK, L. KŘIVSKÝ
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Solar X-Ray Emission

1994
Abstract The curious optical emission spectrum of the solar corona puzzled spectroscopists for decades until it was suggested by Grotrian ( l 931, 1933, 1939) that the temperature is of the order of 106K. With this possibility in mind Edlen (1942a,b) was able to identify nineteen of the coronal lines (Lyot, 193:J) as arising from ...
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Differential emission measure distributions in X-ray solar flares

Advances in Space Research, 2008
Abstract X-ray spectrometer RESIK has observed spectra in the four wavelength bands from 3.3 A to 6.1 A. This spectral range contains many emission lines of H- and He-like ions for Si, S, Ar and K. These lines are formed in plasma of coronal temperatures ( T  > 3 MK).
A. Kepa, B. Sylwester, M. Siarkowski, J. Sylwester   +3 more
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X-ray and gamma-ray emission from solar flares

Physics-Uspekhi, 2020
Abstract We present a brief review of the contemporary understanding of and topical problems in solar flare physics that can be clarified by methods of X-ray and gamma-ray astronomy. The review focuses on several issues, including the conditions and mechanisms of electron acceleration in solar flares, the flare ...
A L Lysenko, D D Frederiks, G D Fleishman, R L Aptekar, A T Altyntsev, S V Golenetskii, D S Svinkin, MV Ulanov, A Tsvetkova, A V Ridnaia   +9 more
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Solar tracking: design and simulation (X-ray emission detection)

[1988] Proceedings. The Twentieth Southeastern Symposium on System Theory, 2003
A solar fine tracking system has been designed and simulated for the pointing of a hard X-ray experiment (pinhole/occulter facility) to be flown on the Space Shuttle or a high altitude balloon. The system hardware consists of a uniform-diameter pinhole camera, photodetector, and sample/hold and analog-to-digital converting circuits.
M. Greene, null Hong Tan
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Observations of hard X-ray emission from solar flares

Journal of Geophysical Research, 1966
Spectral measurements of solar X rays with photon energy greater than 20 kev were carried out in 1959 during portions of three class 2+ solar flares. Two of the flares showed strong fluxes with spectra equivalent to that expected from a thermal plasma with temperature ∼108 degrees.
T. A. Chubb, R. W. Kreplin, H. Friedman
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Theory of X-Ray Emissions in Solar Flaring Loops

2018
X-rays are one of the important way to observe and study the solar flares which are able to radiate the emissions with a wide spectrum. Observationally, the soft and hard X-rays are dependent on the energy, the low and high bands respectively. Physically, the former is related with the thermal plasma, while the latter is produced by the NT electrons ...
Guangli Huang, Victor F. Melnikov, Haisheng Ji, Zongjun Ning   +3 more
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Fe XVIII EMISSION LINES IN SOLAR X-RAY SPECTRA

Solar Physics, 1997
We have calculated intensity ratios for emission lines of Fexviii in the 13–94 A wavelength range at electron temperatures characteristic of the solar corona, T e = 2–10 x 106 K. Our model ion includes data for transitions among the 2s 22p 5 , 2s2p 6, 2s 22p 43l, and 2s2p 53l (l = s, p, and d) states.
G. A. WARREN, F. P. KEENAN, C. J. GREER, K. J. H. PHILLIPS, M. E. BRUNER, W. A. BROWN, D. L. McKENZIE   +6 more
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