scholarly journals Cross sections relevant toγ-ray line emission in solar flares:3He-induced reactions on16Onuclei

2003 ◽  
Vol 68 (2) ◽  
Author(s):  
V. Tatischeff ◽  
J. Duprat ◽  
J. Kiener ◽  
M. Assunção ◽  
A. Coc ◽  
...  
Keyword(s):  
Cross Sections ◽  
Solar Flares ◽  
Line Emission

scholarly journals SolpeX: the soft X-ray flare polarimeter–spectrometer for the ISS

2014 ◽  
Vol 10 (S305) ◽  
pp. 114-120
Author(s):  
Janusz Sylwester ◽  
Stefan Płocieniak ◽  
Jarosław Bakała ◽  
Żaneta Szaforz ◽  
Marek Stȩślicki ◽  
...  
Keyword(s):  
Solar Flares ◽  
Line Emission ◽  
Impulsive Phase ◽  
Particle Beams ◽  
X Ray ◽  
Hot Plasma ◽  
Spectral Imager ◽  
Polarized Bremsstrahlung ◽  
Made In ◽  
Fast Rotating

AbstractWe present the innovative soft X-ray spectro-polarimeter, SolpeX. This instrument consists of three functionally independent blocks. They are to be included into the Russian instrument KORTES, to be mounted onboard the ISS. The three SolpeX units are: a simple pin-hole X-ray spectral imager, a polarimeter, and a fast-rotating drum multiple-flat-crystal Bragg spectrometer. Such a combination of measuring blocks will offer a new opportunity to reliably measure possible X-ray polarization and spectra of solar flares, in particular during the impulsive phase. Polarized Bremsstrahlung and line emission due to the presence of directed particle beams will be detected, and measurements of the velocities of evaporated hot plasma will be made. In this paper we discuss the details of the construction of the SolpeX units. The delivery of KORTES with SolpeX to the ISS is expected to happen in 2017/2018.

scholarly journals Modeling the Infrared Magnesium and Hydrogen Lines from Quiet and Active Solar Regions

1994 ◽  
Vol 154 ◽  
pp. 323-339
Author(s):  
E. H. Avrett ◽  
E. S. Chang ◽  
R. Loeser
Keyword(s):  
Cross Sections ◽  
Line Emission ◽  
Atmospheric Model ◽  
Atmospheric Temperature ◽  
Atomic Data ◽  
Atmospheric Models ◽  
Spatial Features ◽  
Highly Sensitive ◽  
Hydrogen Lines ◽  
The Continuum

The emission lines of Mg I at 7.4, 12.2, and 12.3 μm are now known to be formed in the upper photosphere; the line emission is due to collisional coupling of higher levels with the continuum together with radiative depopulation of lower levels. These combined effects cause the line source functions of high-lying transitions to exceed the corresponding Planck functions. However, there are uncertainties in a) the relevant atomic data, particularly the collisional rates and ultraviolet photoionization rates, and b) the sensitivity of the calculated results to changes in atmospheric temperature and density. These uncertainties are examined by comparing twelve calculated Mg I line profiles in the range 2.1-12.3 μm with ATMOS satellite observations. We show results based on different rates, and using different atmospheric models representing a range of dark and bright spatial features. The calculated Mg profiles are found to be relatively insensitive to atmospheric model changes, and to depend critically on the choice of collisional and photoionization rates. We find better agreement with the observations using collision rates from van Regemorter (1962) rather than from Seaton (1962). We also compare twelve calculated hydrogen profiles in the range 2.2-12.4 μm with ATMOS observations. The available rates and cross sections for hydrogen seem adequate to account for the observed profiles, while the calculated lines are highly sensitive to atmospheric model changes. These lines are perhaps the best available diagnostics of the temperature and density structure of the photosphere and low chromosphere. Further calculations based on these infrared hydrogen lines should lead to greatly improved models of the solar atmosphere.

Iron Line Emission at 1.9 Å during Solar Flares

1970 ◽  
Vol 160 ◽  
pp. 309 ◽  
Author(s):  
J. L. Culhane ◽  
K. J. H. Phillips
Keyword(s):  
Solar Flares ◽  
Line Emission ◽  
Iron Line

Examinations of Charge Transfer between Ionized He and P, S, and Cl in a Microwave-Induced Plasma

1995 ◽  
Vol 49 (12) ◽  
pp. 1781-1788 ◽  
Author(s):  
Patricia G. Brandl ◽  
Jon W. Carnahan
Keyword(s):  
Charge Transfer ◽  
Energy Level ◽  
Cross Sections ◽  
Vacuum Ultraviolet ◽  
Energy Levels ◽  
Line Emission ◽  
High Electron ◽  
Emission Data ◽  
Microwave Induced Plasma ◽  
Uv Visible

Charge transfer between monomer helium ions and nonmetals has been postulated to be the source of high nonmetal ion populations in high electron density (> 1014 e−/cm3) discharges. In this study, overpopulations of excited Cl, P, and S ion energy levels in a helium microwave-induced plasma are examined using ion and atom line emission intensity data and charge transfer theory. The resonance emission lines from phosphorous, sulfur, and chlorine were examined. To examine these highly energetic lines, wavelengths in the vacuum-ultraviolet and the ultraviolet-visible (UV-visible) spectral regions were monitored. Energy-level population calculations were performed on similar UV-visible emission data from the literature. Charge transfer ionization cross sections are calculated for these elements. To obtain an indication of the significance of charge transfer, these parameters are compared to the behavior that would be expected if the plasma were in local thermodynamic equilibrium, and kinetically dominant processes such as CT were not considered. These evaluations, with the aid of energy-level diagrams, help to explain the spectroscopic behavior of these nonmetals in the helium discharge.

scholarly journals Observations and modeling of the ultraviolet emission of solar flares

2015 ◽  
Vol 11 (S320) ◽  
pp. 57-59
Author(s):  
Katarzyna Mikuła ◽  
Arkadiusz Berlicki ◽  
Petr Heinzel
Keyword(s):  
Uv Radiation ◽  
Solar Flares ◽  
Line Emission ◽  
Uv Spectra ◽  
Interface Region ◽  
Continuum Emission ◽  
Ultraviolet Emission ◽  
Imaging Spectrograph ◽  
The Continuum

AbstractIn this paper we present the method of using far UV spectra of the flare observed by Interface Region Imaging Spectrograph (IRIS) for determination of the contribution of the continuum emission to the total UV radiation observed e.g. by SDO in 1600 Å channel. In our method the Si IV (1402.77 Å) line observed by IRIS is used as a proxy of C IV line emission contained in SDO/AIA UV images. Determined intensity of the flare continuum emission can be used to study the physics of the flare heated chromosphere and for better understanding of the emission mechanisms.

YOHKOH Observations of Fe XXVI X-Ray Line Emission from Solar Flares

1996 ◽  
Vol 464 ◽  
pp. 487 ◽  
Author(s):  
C. D. Pike ◽  
K. J. H. Phillips ◽  
J. Lang ◽  
A. Sterling ◽  
T. Watanabe ◽  
...  
Keyword(s):  
Solar Flares ◽  
Line Emission ◽  
X Ray
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