scholarly journals Study of opacity broadening in spectral lines for helium like ions in aluminum plasma which produced by laser

2011 ◽  
Vol 8 (1) ◽  
pp. 54-58
Author(s):  
Baghdad Science Journal
Keyword(s):  
Theoretical Analysis ◽  
Spectral Line ◽  
Quantum Number ◽  
Plasma Density ◽  
Energy Levels ◽  
Spectral Lines ◽  
Aluminum Plasma

A theoretical analysis studied was performed to study the opacity broadening of spectral lines emitted from aluminum plasma produced by Nd-YLF laser. The plasma density was in the range 1028-1026 )) m-3 with length of plasma about ?300) m) , the opacity was studied as function of plasma density & principle quantum number. The results show that the opacity broadening increases as plasma density increases & decreases with the spacing between energy levels of emission spectral line.

scholarly journals Emission Spectra for the Isotopic Molecule Lithium Hydride

2014 ◽  
Vol 11 (2) ◽  
pp. 535-539
Author(s):  
Baghdad Science Journal
Keyword(s):  
Spectral Line ◽  
Quantum Number ◽  
Rotational Quantum Number ◽  
Electronic States ◽  
Emission Spectra ◽  
Lithium Hydride ◽  
Spectral Lines ◽  
Isotopic Molecule

A study of the emission spectra of isotopic for electronic states has been carried out. The energies of the vibration levels ( =0,1,..25) and the values of spectral lines R(J) and P(J) versus rotational quantum number (J=0,1..25). It was found that were an increase of the value of R(J) with the increase of the values of J was found while the value of P(J) decreases with decreasing of the values of J . It was found that corresponding to R(J) and P(J) the spectral line R(J) increases when the values of m increased.

Spectral line list of potential cosmochronological interest deduced from new calculations of radiative transition rates in singly ionized thorium (Th ii)

2020 ◽  
Vol 496 (4) ◽  
pp. 4507-4516 ◽  
Author(s):  
S Gamrath ◽  
M R Godefroid ◽  
P Palmeri ◽  
P Quinet ◽  
K Wang
Keyword(s):  
Spectral Line ◽  
Radiative Decay ◽  
Energy Levels ◽  
Radioactive Decay ◽  
Wavelength Region ◽  
Radiative Transition ◽  
Spectral Lines ◽  
Oscillator Strengths ◽  
Hartree Fock ◽  
Stellar Ages

ABSTRACT In this work, we report a list of 91 strong Th ii spectral lines in the visible wavelength region that could be used as cosmochronometers in future investigations to determine stellar ages from thorium radioactive decay. This list was established on the basis of a pseudo-relativistic Hartree–Fock model including core-polarization corrections (HFR+CPOL) allowing us to compute the corresponding radiative decay parameters, the latter being found to be in good overall agreement with the most accurate experimental data when available. Besides this semi-empirical approach, the fully relativistic ab initio multiconfiguration Dirac–Hartree–Fock (MCDHF) method was attempted, showing large discrepancies with both the present HFR+CPOL and the most recent experimental oscillator strengths, although the calculated wavelengths from theoretical energy levels agreed with observed spectral line wavelengths within 2.4  per cent.

scholarly journals Time Periodic Perturbations of Quantum Systems

1979 ◽  
Vol 34 (12) ◽  
pp. 1404-1409 ◽  
Author(s):  
A. Kelemen
Keyword(s):  
Spectral Line ◽  
Quantum System ◽  
Energy Levels ◽  
Quantum Systems ◽  
Spectral Lines ◽  
Arbitrary Distribution ◽  
Periodic Perturbations ◽  
The Mean ◽  
Time Periodic

Abstract We discuss a method of calculating the mean energy of a quantum system if the latter is subjected to time periodic perturbations. This, e.g., includes the possibility of determining shapes of spectral lines for an arbitrary distribution of nonperturbed energy levels. The method is studied on a system of order 2 whose spectral line is exactly lorentzian. We prove that the next to lowest approximation reproduces this form exactly.

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.

scholarly journals Determination of metallicity of the HR7914 solar-like star

2003 ◽  
pp. 69-74 ◽  
Author(s):  
Oliver Vince ◽  
Istvan Vince
Keyword(s):  
Spectral Line ◽  
Stellar Atmosphere ◽  
Astronomical Observatory ◽  
Program Package ◽  
Spectral Lines ◽  
Iron Abundance ◽  
Microturbulent Velocity

By using the Blackwell program package by R.O. Gray, the metallicity of the HR7914 solar-like star was determined. The program package utilizes measured equivalent widths of several chosen neutral iron spectral lines from the observed spectra, appropriate atomic and spectral line parameters and adequate Kurucz?s stellar atmosphere models. The method is based on determination of the minimum dispersion of the iron abundance versus microturbulent velocity functions for the selected neutral iron spectral lines. The spectra were observed at National Astronomical Observatory Rozhen (NAO Rozhen), Bulgaria, using the 2m-telescope and Coude spectrograph. They were reduced with the IRAF program package. The measurement of the spectral line parameters was done with the SPE program package. The metallicity of the HR7914 solar-like star was determined to be 0.02.

scholarly journals VI. Corrections to the computed lengths of waves of light published in the Philosophical Transactions of the year 1868

1872 ◽  
Vol 162 ◽  
pp. 89-109
Keyword(s):  
Spectral Line ◽  
Royal Society ◽  
Wave Length ◽  
Solar Spectrum ◽  
Spectral Lines ◽  
Fifth Order ◽  
Principal Lines ◽  
General Table

In a paper communicated to the Royal Society in the year 1867, and printed in the Philosophical Transactions for 1868, I attempted the computation of the Lengths of Waves of Light for all the lines which Kirchhoff had observed in the Solar Spectrum, by adopting an algebraical formula of the fifth order, and substituting in it for every spectral line the value of Kirchhoff’s measure for that line, the numerical bases of the formula being derived from Fraunhofer’s and Ditscheiner’s measures of the wave-lengths for six principal lines. Subsequently I obtained the means of comparing many of my computed results with measures of wave-lengths by Ångstrȍm and Ditscheiner, and l found that the discordances were far larger than I had anticipated. I remarked, however, “By means of the comparison........ there is no difficulty in computing for any other line the correction that ought to be applied to the wave-length in the principal Tables, in order to exhibit the true wave-lengths on Ditscheiner’s scale, without appreciable error.” Want of leisure long prevented me from entering upon the examination necessary for preparing, in a form easy for applications, the correction which my numbers required. Lately, however, I have taken it up; and I have constructed a Table of corrections to the numbers of my Table generally, and I have applied them, both to the general Table of wave-lengths and to the values of wave-lengths for the spectral lines of the atmosphere and several metals (the accurate exhibition of which was, in fact, the first object of my computations). I now offer these corrections and corrected numbers for the acceptance of the Royal Society.

Vacuum polarization in muonic and exotic atoms: the Lamb shift at medium Z and high n

2007 ◽  
Vol 85 (5) ◽  
pp. 551-561 ◽  
Author(s):  
E Yu. Korzinin ◽  
V G Ivanov ◽  
S G Karshenboim
Keyword(s):  
Quantum Number ◽  
Lamb Shift ◽  
Vacuum Polarization ◽  
Principal Quantum Number ◽  
Energy Levels ◽  
Exotic Atoms ◽  
Atomic States

We present new results on various asymptotics for the Uehling contribution to the energy levels in atomic states in hydrogen-like atoms that have a principal quantum number n with a high value. The results may be applied to conventional atoms (with an orbiting electron) as well as to muonic, pionic, antiprotonic, and other exotic atoms.PACS Nos.: 36.10.Gv, 31.30.Jv

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