scholarly journals Pressure Broadening of Some He I Lines

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Banaz Omar
Keyword(s):  
Stark Effect ◽  
Statistical Approach ◽  
Stark Broadening ◽  
Line Broadening ◽  
Pressure Broadening ◽  
Dense Plasmas ◽  
Quasistatic Approximation ◽  
Line Shapes ◽  
Quadratic Stark Effect ◽  
Quantum Statistical

Quantum statistical approach is adopted for calculating the spectral line shapes of neutral helium in dense plasmas. Stark broadening of isolated He I lines 5048 Å (), 3889 Å (), and 3188Å () is presented. Based on thermodynamic Green's function, the electronic contribution to the shift and width is considered. The participation of ions to the line broadening is treated in a quasistatic approximation, by taking both quadratic Stark effect and quadrupole interaction into account. The calculated shifts and widths are compared with existing data.

scholarly journals Spectral Line Broadening in Dense Plasmas

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Banaz Omar
Keyword(s):  
Spectral Line ◽  
Stark Effect ◽  
Theoretical Data ◽  
Correlation Effect ◽  
Line Broadening ◽  
Dense Plasmas ◽  
Quasistatic Approximation ◽  
Dynamic Screening ◽  
Spectral Line Broadening ◽  
Good Agreement

Spectral line broadening is calculated based on a microscopic quantum statistical approach. By using thermodynamic Green's function, plasma correlation effect, electrostatic and dynamic screening, and perturber-radiator interaction are taken into account. Ions are treated in quasistatic approximation due to Stark effect. The line broadening for 6678 Å (21P-31D) and 5016 Å (21S-31P) transitions of neutral helium is calculated in the electron density range ne=(0.25–50)×1022 m-3 and temperature range T=(0.5–4)×104 K, and the density and temperature dependence of the line width are investigated. A good agreement is shown by comparing the calculated values with the existing experimental and theoretical data.

Profiles of Pressure Broadened Spectral Lines in an Arc Plasma

2005 ◽  
Vol 60 (10) ◽  
pp. 727-735
Author(s):  
Reda A. El-Koramy ◽  
Abd El-Halim A. Turky
Keyword(s):  
Alkali Metals ◽  
Stark Effect ◽  
Point Of View ◽  
Spectral Lines ◽  
Pressure Broadening ◽  
Static Approximation ◽  
Pressure Line ◽  
Pressure Profiles ◽  
Impact Approximation ◽  
Quadratic Stark Effect

Spectral analysis of the alkali metals is characterized by pressure profiles. In the present work an electric arc has been used to calibrate the half-width of the intensity used in the construction of the ArI natural line at 4300 Å with a trace of evaporated rubidium at pressures of 1, 2 and 3 atmospheres. The results agree well with those obtained by Kusch’s line absorption equation in an electric furnace in the point of view of impact approximation, showing that the widths of the lines have Lorentz shapes. It is found that a simple treatment can be given using the quasi-static approximation of pressure broadening developed by Unsöld. The agreement of the results is good only if the shifts are large. The study shows that the pressure line profile is made up of a sum of dispersion profiles and asymmetric terms which arise from interactions of quadratic Stark effect, commonly assumed to be the force in causing foreign gas broadening

scholarly journals The Determination of Spectral Line Shapes for Hydrogenic Ions in Dense Plasmas

1977 ◽  
Vol 43 ◽  
pp. 3-3
Author(s):  
R. W. Lee
Keyword(s):  
Spectral Line ◽  
Ion Dynamics ◽  
Line Broadening ◽  
Dense Plasmas ◽  
Preliminary Results ◽  
Line Shapes ◽  
Hydrogenic Ions ◽  
Consistent Formulation ◽  
Fusion Type

The task of calculating line-shapes in ultra-dense fusion type plasmas is discussed. The application of line-broadening theory to derive a consistent formulation for ionized emitters including ion dynamics, Debye shifts and perturber-ion correlations is outlined. The difficulties in extending the standard theories are explored with special emphasis given to the modifications necessary to treat the cases which occur in the experimental situations. Preliminary results will be presented.

Quantum-statistical T-matrix approach to line broadening of hydrogen in dense plasmas

2010 ◽  
Author(s):  
Sonja Lorenzen ◽  
August Wierling ◽  
Heidi Reinholz ◽  
Gerd Röpke ◽  
Mark C. Zammit ◽  
...  
Keyword(s):  
Matrix Approach ◽  
Line Broadening ◽  
Dense Plasmas ◽  
T Matrix ◽  
Quantum Statistical

scholarly journals Theoretical and experimental study of complete spectral series as a diagnostic tool for dense plasmas

1987 ◽  
Vol 5 (1) ◽  
pp. 155-162 ◽  
Author(s):  
B. d'Etat ◽  
J. Grumberg ◽  
E. Leboucher ◽  
H. Nguyen ◽  
A. Poquérusse
Keyword(s):  
Experimental Study ◽  
Diagnostic Tool ◽  
Stark Effect ◽  
High Density ◽  
Tunnel Effect ◽  
Spectral Series ◽  
Line Broadening ◽  
Dense Plasmas ◽  
Plasma Ions ◽  
Laser Plasmas

A theoretical and experimental study of line broadening and merging is presented and suggested for diagnosis of high density laser plasmas. For densities larger than 1022 cm−3 the hydrogenlike sequence is reduced to four lines for the emitter ion with ZE = 9. The perturbation effects on the latter come mainly from the interaction with plasma ions and electrons (Stark effect, multipolar interactions, ionization by tunnel effect, polarization line shift …).

scholarly journals Stark-Zeeman Broadening of Spectral Line Shapes in Magnetized Plasmas

Atoms ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 91
Author(s):  
Kamel Ahmed Touati ◽  
Keltoum Chenini ◽  
Mohammed Tayeb Meftah
Keyword(s):  
Magnetic Field ◽  
Spectral Line ◽  
Stark Effect ◽  
Line Broadening ◽  
Lyman Alpha ◽  
Line Shapes ◽  
Field Temperature ◽  
Motional Stark Effect ◽  
On Line ◽  
The Magnetic Field

In this work, we studied the Lyman-alpha line in the presence of a magnetic field, such as the ones found at the edge of tokamaks. The emphasis is on the contribution of the motional Stark effect on line broadening, which may have comparable effects to the internal plasma microfields for the spectral line in question. The effect of the magnetic field, temperature, and the Maxwell distribution of the ion velocities and density on Lyman-alpha are studied.

Critical Raman line shape behavior of fluid nitrogen

2004 ◽  
Vol 76 (1) ◽  
pp. 147-155 ◽  
Author(s):  
M. Musso ◽  
F. Matthai ◽  
D. Keutel ◽  
K.-L. Oehme
Keyword(s):  
Raman Line ◽  
Line Shape ◽  
Line Broadening ◽  
Vibrational Resonance ◽  
Critical Isochore ◽  
Molecular Fluids ◽  
Detection Techniques ◽  
Gas Phases ◽  
Line Shapes ◽  
Band Position

Isotropic Raman line shapes of simple molecular fluids exhibit critical line broadening near their respective liquid-gas critical points. In order to observe this phenomenon, it is essential that the band position of a given vibrational mode is density-dependent, and that vibrational depopulation processes negligibly contribute to line broadening. Special attention was given to the fact that the isotropic (i.e., nonrotationally broadened) line shape of liquid N2 is affected by resonant intermolecular vibrational interactions between identical oscillators. By means of the well-chosen isotopic mixture (14N2).975 - (14N15N).025, the temperature and density dependences of shift, width, and asymmetry of the resonantly coupled 14N2 and, depending on the S/N ratio available, of the resonantly uncoupled 14N15N were determined, with up to milli-Kelvin resolution, in the coexisting liquid and gas phases and along the critical isochore, using a highest-resolution double monochromator and modern charge-coupled device detection techniques. Clear evidence was found that vibrational resonance couplings are present in all dense phases studied.

scholarly journals From the Vector to Scalar Perturbations Addition in the Stark Broadening Theory of Spectral Lines

Universe ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 176
Author(s):  
Valery Astapenko ◽  
Andrei Letunov ◽  
Valery Lisitsa
Keyword(s):  
Spectral Line ◽  
Stark Effect ◽  
Coulomb Field ◽  
Spectral Lines ◽  
Alternative Methods ◽  
Scalar Perturbation ◽  
Numerical Comparison ◽  
Line Shapes ◽  
Stark Effects ◽  
The Impact

The effect of plasma Coulomb microfied dynamics on spectral line shapes is under consideration. The analytical solution of the problem is unachievable with famous Chandrasekhar–Von-Neumann results up to the present time. The alternative methods are connected with modeling of a real ion Coulomb field dynamics by approximate models. One of the most accurate theories of ions dynamics effect on line shapes in plasmas is the Frequency Fluctuation Model (FFM) tested by the comparison with plasma microfield numerical simulations. The goal of the present paper is to make a detailed comparison of the FFM results with analytical ones for the linear and quadratic Stark effects in different limiting cases. The main problem is connected with perturbation additions laws known to be vector for small particle velocities (static line shapes) and scalar for large velocities (the impact limit). The general solutions for line shapes known in the frame of scalar perturbation additions are used to test the FFM procedure. The difference between “scalar” and “vector” models is demonstrated both for linear and quadratic Stark effects. It is shown that correct transition from static to impact limits for linear Stark-effect needs in account of the dependence of electric field jumping frequency in FFM on the field strengths. However, the constant jumping frequency is quite satisfactory for description of the quadratic Stark-effect. The detailed numerical comparison for spectral line shapes in the frame of both scalar and vector perturbation additions with and without jumping frequency field dependence for the linear and quadratic Stark effects is presented.

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