Some peculiarities in stark broadening of spectral lines of hydrogen-like ions in a dense plasma

Stark broadening of Lyman lines in high density plasmas is treated theoretically to study the effects of the fields inside the plasmas, the microfield, and the oscillating fields from Langmuir waves. Resonance features are expected to be observed from the line profiles, especially about the microfield.

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Specific Features of Stark Broadening of Helium-Like Multi-Charged Ion Spectral Lines

International Astronomical Union Colloquium ◽

10.1017/s025292110010747x ◽

1988 ◽

Vol 102 ◽

pp. 83-86

Author(s):

V.P. Gavrilenko ◽

I.M. Gaisinsky ◽

Y.O. Ispolatov ◽

E.A. Oks

Keyword(s):

Dense Plasma ◽

Energy Levels ◽

Spectral Lines ◽

Stark Broadening ◽

Ion Energy ◽

Fine Structures ◽

The Mean ◽

Active Research ◽

The One ◽

Charged Ions

Recently as a result of more active research on dense high temperature plasmas prominent importance has been acquired by the development of the theory of Stark broadening of multi-charged ions’Spectral lines (SL). This theory must take into account, on the one hand, the presence of fine structures in ion energy levels, and on the other hand, the effects appearing in the dense plasma:(1) dipole as well as quadrupole interaction with plasma ion microfield; (2) plasma polarization shift (PPS) of SL due to the mean electric field where the ion emitter is situated. Over the recent years a number of papers has appeared [1-4] which consider different aspects of the theory for ions with one and with two electrons.

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Monopole Contribution to the Stark Width of Hydrogenlike Spectral Lines in Plasmas: Analytical Results

Plasma ◽

10.3390/plasma3040013 ◽

2020 ◽

Vol 3 (4) ◽

pp. 180-186

Author(s):

Eugene Oks

Keyword(s):

Spectral Lines ◽

Electron Velocity ◽

Line Profiles ◽

Stark Broadening ◽

Astrophysical Plasmas ◽

Ion Density ◽

Controlled Fusion ◽

Plasma Research ◽

The Magnetic Field ◽

Stark Width

One of the most reliable and frequently used methods for diagnosing various laboratory and astrophysical plasmas is based on the Stark broadening of spectral lines. It allows for determining from the experimental line profiles important parameters, such as the electron density and temperature, the ion density, the magnetic field, and the field strength of various types of the electrostatic plasma turbulence. Since, in this method, radiating atoms or ions are used as the sensitive probes of the above parameters, these probes have to be properly calibrated. In other words, an accurate theory of the Stark broadening of spectral lines in plasmas is required. In the present paper, we study, analytically, the monopole contribution to the Stark width of hydrogen-like spectral lines in plasmas. For this purpose, we use the formalism from paper by Mejri, Nguyen, and Ben Lakhdar. We show that the monopole contribution to the width has a non-monotonic dependence on the velocity of perturbing electrons. Namely, at relatively small electron velocities, the width decreases as the velocity increases. Then it reaches a minimum and (at relatively large electron velocities), as the velocity further increases, the width increases. The non-monotonic dependence of the monopole contribution to the width on the electron velocity is a counter-intuitive result. The outcome that at relatively large electron velocities, the monopole contribution to the width increases with the increase in the electron velocity is in a striking distinction to the dipole contribution to the width, which decreases as the electron velocity increases. We show that, in the situation encountered in various areas of plasma research (such as in magnetically-controlled fusion), where there is a relativistic electron beam (REB) in a plasma, the monopole contribution to the width due to the REB exceeds the corresponding dipole contribution by four orders of magnitude and practically determines the entire Stark width of hydrogenic spectral lines due to the REB.

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Plasma Correlation Effects on Stark Broadening

Zeitschrift für Naturforschung A ◽

10.1515/zna-1975-6-733 ◽

1975 ◽

Vol 30 (6-7) ◽

pp. 913-915 ◽

Cited By ~ 6

Author(s):

H. Capes ◽

D. Voslamber

Keyword(s):

Spectral Line ◽

High Frequency ◽

High Density ◽

Line Profiles ◽

Correlation Effects ◽

Stark Broadening

Abstract The influence on spectral line profiles of a possible coupling between the low and high frequency parts of the plasma microfield, and of ternary plasma correlations is investigated. Both effects may have some importance in high density plasmas (e. g. arc experiments), but the first of them is shown to be generally predominant.

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Diagnostic of Langmuir Solitons in Plasmas Using Hydrogenic Spectral Lines

Atoms ◽

10.3390/atoms7010025 ◽

2019 ◽

Vol 7 (1) ◽

pp. 25 ◽

Cited By ~ 1

Author(s):

Eugene Oks

Keyword(s):

Promising Result ◽

Spectral Lines ◽

Successful Implementation ◽

Line Profiles ◽

General Study ◽

Langmuir Waves ◽

Spectroscopic Diagnostics ◽

Peak Intensity ◽

History Of ◽

Langmuir Solitons

The development of various spectroscopic diagnostics of relatively weak Langmuir waves in plasmas and their successful implementation have a history of over 50 years. As for spectroscopic diagnostics of Langmuir solitons (i.e., relatively strong Langmuir waves) in plasmas, there have only been very few theoretical papers. The most promising result so far was based on using satellites of the dipole-forbidden spectral lines of He, Li, or He-like and Li-like ions. It was shown that, in the case of Langmuir solitons, the peak intensity of the satellites of the dipole-forbidden lines can be significantly enhanced—by orders of magnitude—compared to the case of non-solitonic Langmuir waves. This distinctive feature of satellites under Langmuir solitons allows them to be distinguished from non-solitonic Langmuir waves. In the present paper, we perform a general study of the effects of Langmuir solitons on arbitrary spectral lines of hydrogen or hydrogen-like ions. Then, using the Ly-beta line as an example, we compare the main features of the profiles for the case of the Langmuir solitons with the case of the non-solitonic Langmuir waves of the same amplitude. We also show how the line profiles depend on the amplitude of the Langmuir solitons and on their separation from each other within the sequence of the solitons.

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The Interpretation of Line Profiles

International Astronomical Union Colloquium ◽

10.1017/s0252921100053318 ◽

1977 ◽

Vol 36 ◽

pp. 191-215

Author(s):

G.B. Rybicki

Keyword(s):

Magnetic Fields ◽

Atomic Physics ◽

Velocity Fields ◽

Spectral Lines ◽

Inhomogeneous Structure ◽

The Sun ◽

Line Profiles ◽

Physical Phenomena

Observations of the shapes and intensities of spectral lines provide a bounty of information about the outer layers of the sun. In order to utilize this information, however, one is faced with a seemingly monumental task. The sun’s chromosphere and corona are extremely complex, and the underlying physical phenomena are far from being understood. Velocity fields, magnetic fields, Inhomogeneous structure, hydromagnetic phenomena – these are some of the complications that must be faced. Other uncertainties involve the atomic physics upon which all of the deductions depend.

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AGN evolution as seen in spectral lines: The case of narrow-line Seyfert 1s

Proceedings of the International Astronomical Union ◽

10.1017/s1743921320002653 ◽

2019 ◽

Vol 15 (S356) ◽

pp. 94-94

Author(s):

Marco Berton

Keyword(s):

Active Galactic Nuclei ◽

Galactic Nuclei ◽

Spectroscopic Studies ◽

Spectral Lines ◽

Narrow Line ◽

Line Profiles ◽

Line Shapes ◽

Fundamental Information ◽

Line Region ◽

Gaussian Samples

AbstractLine profiles can provide fundamental information on the physics of active galactic nuclei (AGN). In the case of narrow-line Seyfert 1 galaxies (NLS1s) this is of particular importance since past studies revealed how their permitted line profiles are well reproduced by a Lorentzian function instead of a Gaussian. This has been explained with different properties of the broad-line region (BLR), which may present more pronounced turbulent motions in NLS1s with respect to other AGN. We investigated the line profiles in a recent large NLS1 sample classified using SDSS, and we divided the sources into two subsamples according to their line shapes, Gaussian or Lorentzian. The line profiles seem to separate all the properties of NLS1s. Black hole mass, Eddington ratio, [OIII] luminosity, and Fe II strength are all very different in the Lorentzian and Gaussian samples, as well as their position on the quasar main sequence. We interpret this in terms of evolution within the class of NLS1s. The Lorentzian sources may be the youngest objects, while Gaussian profiles may be typically associated to more evolved objects. Further detailed spectroscopic studies are needed to fully confirm our hypothesis.

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The Semiclassical Limit of the Gailitis Formula Applied to Electron Impact Broadening of Spectral Lines of Ionized Atoms

Atoms ◽

10.3390/atoms9020029 ◽

2021 ◽

Vol 9 (2) ◽

pp. 29

Author(s):

Sylvie Sahal-Bréchot

Keyword(s):

Electron Impact ◽

Classical Limit ◽

Semiclassical Limit ◽

Spectral Lines ◽

Stark Broadening ◽

Feshbach Resonances

The present paper revisits the determination of the semi-classical limit of the Feshbach resonances which play a role in electron impact broadening (the so-called “Stark“ broadening) of isolated spectral lines of ionized atoms. The Gailitis approximation will be used. A few examples of results will be provided, showing the importance of the role of the Feshbach resonances.

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