scholarly journals Laboratory Calibrations of Fe xii–xiv Line-intensity Ratios for Electron Density Diagnostics

2020 ◽  
Vol 890 (1) ◽  
pp. 77 ◽  
Author(s):  
Thusitha Arthanayaka ◽  
Peter Beiersdorfer ◽  
Gregory V. Brown ◽  
Ming Feng Gu ◽  
Michael Hahn ◽  
...  
Keyword(s):  
Electron Density ◽  
Line Intensity ◽  
Intensity Ratios ◽  
Density Diagnostics

scholarly journals Density Diagnostics of Solar Emission Lines from the Nitrogen-like Mg VI Ion

1990 ◽  
Vol 142 ◽  
pp. 443-444
Author(s):  
P.K. Raju ◽  
R. Vasundhara
Keyword(s):  
Electron Density ◽  
Line Intensity ◽  
Emission Lines ◽  
Solar Plasma ◽  
Theoretical Line ◽  
Intensity Ratios ◽  
Density Diagnostics

The variation of theoretical line intensity ratios with electron density for Mg VI ion are presented. This study indicates that the line intensity ratios for Mg VI can be used to infer electron density for solar plasma.

scholarly journals X-ray Lines From Mg VIII and Si X Ions and Their Diagnostic Use

1990 ◽  
Vol 115 ◽  
pp. 40-43
Author(s):  
Bhola N. Dwivedi
Keyword(s):  
Electron Density ◽  
Line Intensity ◽  
Coronal Holes ◽  
Emission Lines ◽  
X Ray ◽  
Quiet Sun ◽  
Diagnostic Use ◽  
Line Intensity Ratio ◽  
Theoretical Line ◽  
Intensity Ratios

AbstractThe solar X-ray emission lines from Mg VIII and Si X ions have been studied. The variation of theoretical line intensity ratio I(λ 75.03)/I(λ 74.86) from Mg VIII and I(λ 50.69)/I(λ 50.52) from Si X as a function of electron density is found to be good density monitors of the emitting regions of solar plasma. The computed values of line intensity from these ions based on Kopp and Orrall model have been used to derive electron density of the quiet Sun and coronal holes. The electron densities of 109 cm-3 and 4.6 × 108 cm-3 are estimated at the electron temperatures of 8 x 105 K and 1.6 x 106 K for the quiet Sun whereas the respective values of 5.4 x 108 cm-3 and 1.7 x 108 cm-3 are obtained for the coronal holes. The line intensity ratios studied here are independent of temperature variation and are therefore excellent candidates for electron density diagnostics. However, observational data with improved spectral resolution is needed for using X-ray line pairs studied for their diagnostic use.

Electron Density Dependence of Extreme Ultraviolet Line Intensity Ratios in Ar XIV

2021 ◽  
Vol 921 (2) ◽  
pp. 115
Author(s):  
Nobuyuki Nakamura ◽  
Naoki Numadate ◽  
Yasutaka Kono ◽  
Izumi Murakami ◽  
Daiji Kato ◽  
...  
Keyword(s):  
Density Dependence ◽  
Electron Density ◽  
Line Intensity ◽  
Extreme Ultraviolet ◽  
Intensity Ratios

scholarly journals Diagnostics of EUV Spectral Emission from Boron-like Ions

1996 ◽  
Vol 152 ◽  
pp. 589-593
Author(s):  
Jianfang Peng ◽  
Anil K. Pradhan
Keyword(s):  
Line Intensity ◽  
Theoretical Calculations ◽  
Atomic Data ◽  
Spectral Emission ◽  
Physical Conditions ◽  
Astrophysical Objects ◽  
Recent Developments ◽  
Intensity Ratios ◽  
Density Diagnostics

Recent developments of EUV diagnostics from transitions in Boron-like ions, C II, N III, O IV, Ne VI, Mg VIII, Al IX, Si X, and S XII, are discussed based on new atomic data (Zhang, Graziani & Pradhan (1994)) and systematic theoretical calculations of line intensity ratios (Peng & Pradhan 1995). The available EUV and UV lines which are good temperature and density diagnostics are summarized. Possible applications of these lines to the investigation of the physical conditions in astrophysical objects are proposed.

The relative intensities of nitrogen lines in the semi-coronal regime

1973 ◽  
Vol 9 (1) ◽  
pp. 77-88 ◽  
Author(s):  
W. A. Cilliers ◽  
J. D. Hey ◽  
J. P. S. Rash
Keyword(s):  
Spectral Line ◽  
Electron Temperature ◽  
Electron Density ◽  
Line Intensity ◽  
Intensity Ratio ◽  
Spectral Lines ◽  
Spectral Line Intensity ◽  
Line Intensity Ratio ◽  
Ratio Data ◽  
Intensity Ratios

At plasma densities lower than about 1018 cm-3, strictly speaking, the LTE model cannot be used when the electron temperature is calculated from measured spectral line intensity ratios. In this work a number of nitrogen spectral lines were studied at an electron density of about 1016 cm-3, and the results are discussed with reference to the LTE and semi-coronal models. A method is suggested for analyzing line intensity ratio data from plasmas in the semi-coronal regime.

scholarly journals Different long-term trends of the oxygen red 630.0 nm line nightglow intensity as the result of lowering the ionosphere F2 layer

2008 ◽  
Vol 26 (8) ◽  
pp. 2069-2080 ◽  
Author(s):  
N. B. Gudadze ◽  
G. G. Didebulidze ◽  
L. N. Lomidze ◽  
G. Sh. Javakhishvili ◽  
M. A. Marsagishvili ◽  
...  
Keyword(s):  
Electron Density ◽  
Line Intensity ◽  
Peak Height ◽  
Height Distribution ◽  
Theoretical Simulation ◽  
Type Layer ◽  
Long Term Trends ◽  
The Mean ◽  
Long Term Trend

Abstract. Long-term observations of total nightglow intensity of the atomic oxygen red 630.0 nm line at Abastumani (41.75° N, 42.82° E) in 1957–1993 and measurements of the ionosphere F2 layer parameters from the Tbilisi ionosphere station (41.65° N, 44.75° E) in 1963–1986 have been analyzed. It is shown that a decrease in the long-term trend of the mean annual red 630.0 nm line intensity from the pre-midnight value (+0.770±1.045 R/year) to its minimum negative value (−1.080±0.670 R/year) at the midnight/after midnight is a possible result of the observed lowering of the peak height of the ionosphere F2 layer electron density hmF2 (−0.455±0.343 km/year). A theoretical simulation is carried out using a simple Chapman-type layer (damping in time) for the height distribution of the F2 layer electron density. The estimated values of the lowering in the hmF2, the increase in the red line intensity at pre-midnight and its decrease at midnight/after midnight are close to their observational ones, when a negative trend in the total neutral density of the upper atmosphere and an increase in the mean northward wind (or its possible consequence – a decrease in the southward one) are assumed.

THE CONVERSION LINE INTENSITY RATIOS FOR M4 TRANSITIONS IN Xe AND Ba

1962 ◽  
Vol 40 (9) ◽  
pp. 1258-1264 ◽  
Author(s):  
J. S. Geiger ◽  
R. L. Graham ◽  
F. Brown
Keyword(s):  
Line Intensity ◽  
Conversion Line ◽  
Intensity Ratios
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