Electron impact polarization of atomic spectral lines. I - A general theoretical scheme

1992 ◽  
Vol 392 ◽  
pp. 337 ◽  
Author(s):  
Silvano Fineschi ◽  
Egidio L. degl'Innocenti
Keyword(s):  
Electron Impact ◽  
Spectral Lines ◽  
Theoretical Scheme ◽  
Impact Polarization

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

Atoms ◽  
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.

Electron impact broadening of Si IV spectral lines: Comparison with recent experiments

2012 ◽  
Vol 113 (12) ◽  
pp. 1606-1611 ◽  
Author(s):  
Haykel Elabidi ◽  
Nébil Ben Nessib ◽  
Sylvie Sahal-Bréchot
Keyword(s):  
Electron Impact ◽  
Spectral Lines

The electron-impact broadening of the Nb iii for 5p–5d transitions

2019 ◽  
Vol 491 (3) ◽  
pp. 4382-4386
Author(s):  
Zoran Simić ◽  
Nenad M Sakan
Keyword(s):  
Rare Earth ◽  
Electron Impact ◽  
Rare Earth Element ◽  
Earth Element ◽  
Empirical Method ◽  
Spectral Lines ◽  
Type Star ◽  
Stark Broadening ◽  
Hot Stars ◽  
Semi Empirical

ABSTRACT In this work, we present the data of Stark widths of rare-earth element Nb iii, calculated for 21 spectral lines by using the modified semi-empirical method. Obtained results have been used to study the influence of Stark broadening on spectral lines in hot stars atmospheres such as A-type star and DA and DB white dwarfs.

scholarly journals The electron-impact broadening parameters for Co III spectral lines

2003 ◽  
Vol 399 (2) ◽  
pp. 795-797 ◽  
Author(s):  
D. Tankosić ◽  
L. Č. Popović ◽  
M. S. Dimitrijević
Keyword(s):  
Electron Impact ◽  
Spectral Lines

The Spark Source Mass Spectra of Organic Solids

1965 ◽  
Vol 20 (9) ◽  
pp. 1128-1142 ◽  
Author(s):  
R. C. Faust ◽  
A. E. Fontaine ◽  
B. E. Job ◽  
R. A. Saunders
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
Impact Ionization ◽  
Mass Measurement ◽  
Spectral Lines ◽  
Organic Solids ◽  
Source Mass ◽  
Ion Molecule Reactions ◽  
Electron Impact Mass ◽  
Ionization Methods

Spark source mass spectra of organic solids, obtained on an A.E.I. M.S. 7 spectrometer, have been compared with the conventional mass spectra produced by electron impact ionization of the vapours of these same solids. Although fragmentation in the spark is very high, many more spectral lines being produced than by electron impact, the spark spectrum contains many features, including meta-stable peaks, that point to a similarity between the two ionization methods. It is suggested that electron impact of vaporised species is an important ionization process within the spark. This hypothesis is reinforced by the fact that those materials that could not be vaporised without thermal degradation for electron impact study also gave no spark spectra characteristic of their structure.Improvements in the design of spark source spectrometers would permit identification, by means of accurate mass measurement, of the numerous ions, many of which do not occur in electron impact mass spectra. This might provide an insight into the processes of fragmentation, re-arrange-ment and ion-molecule reactions occuring in the spark.

scholarly journals R-matrix electron-impact excitation data for the N-like iso-electronic sequence

2020 ◽  
Vol 643 ◽  
pp. A95
Author(s):  
Junjie Mao ◽  
N. R. Badnell ◽  
G. Del Zanna
Keyword(s):  
Electron Impact ◽  
Plasma Diagnostics ◽  
Spectral Lines ◽  
Impact Excitation ◽  
Electron Impact Excitation ◽  
Atomic Data ◽  
Astrophysical Plasma ◽  
Wide Range ◽  
The Impact ◽  
Effective Collision

Context. Spectral lines from N-like ions can be used to measure the temperature and density of various types of astrophysical plasmas. The atomic databases of astrophysical plasma modelling codes still have room for improvement in their electron-impact excitation data sets for N-like ions, especially for R-matrix data. This is particularly relevant for future observatories (e.g. Arcus), which will host high-resolution spectrometers. Aims. We aim to obtain level-resolved effective collision strengths for all transitions up to nl = 5d over a wide range of temperatures for N-like ions from O II to Zn XXIV (i.e. O+ to Zn23+) and to assess the accuracy of the present work. We also examine the impact of our new data on plasma diagnostics by modelling solar observations with CHIANTI. Methods. We carried out systematic R-matrix calculations for N-like ions, which included 725 fine-structure target levels in both the configuration interaction target and close-coupling collision expansions. The R-matrix intermediate coupling frame transformation method was used to calculate the collision strengths, while the AUTOSTRUCTURE code was used for the atomic structures. Results. We compare the present results for selected ions with those in archival databases and the literature. The comparison covers energy levels, oscillator strengths, and effective collision strengths. We show examples of improved plasma diagnostics when compared to CHIANTI models, which use only distorted wave data as well as some using previous R-matrix data. The electron-impact excitation data are archived according to the Atomic Data and Analysis Structure (ADAS) data class adf04 and will be available in OPEN-ADAS. The data can be used to improve the atomic databases for astrophysical plasma diagnostics.

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