The spectral line asymmetry of the Doppler effect in relativistic plasmas

2021 ◽  
Author(s):  
Hadda Gossa ◽  
Mohammed Tayeb Meftah ◽  
Keltoum Chenini ◽  
Djamel-Eddine Zenkhri ◽  
Bachir Amieur ◽  
...  
Keyword(s):  
Spectral Line ◽  
Exact Formula ◽  
Laboratory System ◽  
Temperature Plasma ◽  
Relativistic Case ◽  
Relativistic Plasmas ◽  
Gaussian Profile ◽  
Doppler Profile ◽  
Line Asymmetry ◽  
Non Gaussian

Abstract {In this work, we present a comparative study between the relativistic and non- relativistic Doppler effects on spectral line profiles in ultra-hot plasmas at the laboratory system. We have established an exact formula of the relativistic Doppler profile in ultra-high-temperature plasma that is not a Gaussian one (unlike the nonrelativistic Doppler profile that is Gaussian). We have also derived a new FWHM (Full Width at Half Maximum) formula of the corresponding profile that is different from the non-relativistic FWHM (sqrtlog(T=M)). We have also shown that, in the relativistic case, Doppler broadening exhibits an asymmetry of spectral line profile (non- gaussian profile). To ensure the validity of our investigation, we have compared our theoretical calculation with the experimental results that shows a good agreement.

Spatial Dependence of Inverse Raman Signals

1981 ◽  
Vol 35 (6) ◽  
pp. 591-593 ◽  
Author(s):  
Gregory R. Daigneault ◽  
Michael D. Morris
Keyword(s):  
Laser Beam ◽  
Spatial Dependence ◽  
Potassium Nitrate ◽  
Test System ◽  
Pulsed Dye Laser ◽  
Raman Signal ◽  
Gaussian Beams ◽  
Gaussian Profile ◽  
Non Gaussian ◽  
Signal Intensities

The spatial dependence of inverse Raman signal intensities was investigated. Aqueous 0.5 M potassium nitrate in cells ranging from 1 to 50 mm was used as the test system. Three focusing lenses were used. The data do not fit the arctan dependence derived for Gaussian beams. The deviations are ascribed to the non-Gaussian profile of the pulsed dye laser beam.

scholarly journals First evidence of non-Gaussian solar flare EUV spectral line profiles and accelerated non-thermal ion motion

2016 ◽  
Vol 590 ◽  
pp. A99 ◽  
Author(s):  
Natasha L. S. Jeffrey ◽  
Lyndsay Fletcher ◽  
Nicolas Labrosse
Keyword(s):  
Solar Flare ◽  
Spectral Line ◽  
Line Profiles ◽  
Ion Motion ◽  
Non Gaussian

scholarly journals 6Li in metal-poor halo stars: real or spurious?

2009 ◽  
Vol 5 (S265) ◽  
pp. 23-26 ◽  
Author(s):  
M. Steffen ◽  
R. Cayrel ◽  
P. Bonifacio ◽  
H.-G. Ludwig ◽  
E. Caffau
Keyword(s):  
Spectral Line ◽  
Isotopic Ratio ◽  
Line Profiles ◽  
Halo Stars ◽  
Convective Motions ◽  
Symmetric Line ◽  
Line Asymmetry ◽  
Red Wing

AbstractThe presence of convective motions in the atmospheres of metal-poor halo stars leads to systematic asymmetries of the emergent spectral line profiles. Since such line asymmetries are very small, they can be safely ignored for standard spectroscopic abundance analysis. However, when it comes to the determination of the 6Li/7Li isotopic ratio, q(Li)=n(6Li)/n(7Li), the intrinsic asymmetry of the 7Li line must be taken into account, because its signature is essentially indistinguishable from the presence of a weak 6Li blend in the red wing of the 7Li line. In this contribution we quantity the error of the inferred 6Li/7Li isotopic ratio that arises if the convective line asymmetry is ignored in the fitting of the λ6707 Å lithium blend. Our conclusion is that 6Li/7Li ratios derived by Asplund et al. (2006), using symmetric line profiles, must be reduced by typically Δq(Li) ≈ 0.015. This diminishes the number of certain 6Li detections from 9 to 4 stars or less, casting some doubt on the existence of a 6Li plateau.

Spectral-line asymmetry in double-output-cavity lasers

2010 ◽  
Vol 42 (2) ◽  
pp. 439-446 ◽  
Author(s):  
Ahmed Aissani ◽  
Belkacem Meziane ◽  
Karim Battou ◽  
Omar Ziane
Keyword(s):  
Spectral Line ◽  
Output Cavity ◽  
Line Asymmetry ◽  
Cavity Lasers

Spectral line asymmetry of Arcturus

2015 ◽  
Author(s):  
M. M. Razelan ◽  
N. M. M. Said ◽  
H. Y. Chong ◽  
A. H. A. Aziz ◽  
M. Z. Zainuddin
Keyword(s):  
Spectral Line ◽  
Line Asymmetry

scholarly journals Doppler Broadening of Spectral Line Shapes in Relativistic Plasmas

Atoms ◽  
2018 ◽  
Vol 6 (2) ◽  
pp. 16
Author(s):  
Mohammed Meftah ◽  
Hadda Gossa ◽  
Kamel Touati ◽  
Keltoum Chenini ◽  
Amel Naam
Keyword(s):  
Spectral Line ◽  
Doppler Broadening ◽  
Relativistic Plasmas ◽  
Line Shapes

Competitive Oxidation During Buried Oxide Formation Using Separation by Plasma Implantation of Oxygen (Spimox)

1995 ◽  
Vol 388 ◽  
Author(s):  
Jingbao Liu ◽  
S. Sundar Kumar Iyer ◽  
Jing Min ◽  
Paul Chu ◽  
Ron Gronsky ◽  
...  
Keyword(s):  
Oxygen Plasma ◽  
Surface Oxidation ◽  
Silicon On Insulator ◽  
Implantation Technique ◽  
Buried Oxide ◽  
Gaussian Profile ◽  
Different Depths ◽  
Non Gaussian ◽  
Post Implantation ◽  
Si Wafer

AbstractWe have recently demonstrated a new implantation technique called SPIMOX (separation by plasma implantation of oxygen) to synthesize silicon-on-insulator structures using plasma immersion ion implantation (PIII) process. the implantation is performed by applying a large negative bias to a Si wafer immersed in an oxygen plasma created by an ECR source. Since the technique has no mass analysis, coexistence of O+ and O2+ ions in oxygen plasma can cause a non-Gaussian profile of the as-implanted oxygen distribution. We observed that during post-implantation annealing, the ripening process of the oxide precipitates depends on depth and concentration of the oxygen peaks. IN addition, implanted oxygen can migrate towards the Si surface during annealing, preventing a continuous buried oxide layer formation. IN this paper, we report our observation on the effect of the implantation profile on the competitions between internal oxidation at different depths and between internal and surface oxidation processes. With an additional He implantation, we demonstrate that the nucleation of oxide precipitation can be enhanced.

Opacity of Krypton X-ray lines in high-temperature plasma implosion

2019 ◽  
Vol 33 (33) ◽  
pp. 1950418
Author(s):  
Zhiqiang Zhen ◽  
Jian He
Keyword(s):  
High Temperature ◽  
Line Ratio ◽  
Text Line ◽  
X Rays ◽  
Temperature Plasma ◽  
X Ray ◽  
High Temperature Plasma ◽  
Gaussian Profile ◽  
Density Diagnostics ◽  
Escape Factor

For accurate electron temperature and density diagnostics in laser high-temperature plasma implosion, opacity of Krypton (Kr) helium-[Formula: see text] and Balmer-[Formula: see text] lines are discussed, and ratio of escape factor of the two X-rays are calculated, both for Gaussian and Holtzmarkian profiles. Finally, the line ratios of the two X-ray lines are analyzed for optically thin and thick plasmas. Results indicate that for the Gaussian profile, the line ratio varies greatly with the opacity of the Kr helium-[Formula: see text] line, which provides excellent source for temperature and electron density diagnostics; while for the Holtzmarkian profile, the line ratio varies less with the opacity of the Kr helium-[Formula: see text] line, which can be used for escape factor diagnostics. This method is significant in accurate plasma diagnostics using X-rays under the condition of optically thick.

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