Transient Light Emissions from a Laser Perturbed Plasma

1972 ◽  
Vol 50 (19) ◽  
pp. 2338-2347 ◽  
Author(s):  
H. A. Baldis ◽  
R. A. Nodwell ◽  
J. Meyer
Keyword(s):  
Laser Pulse ◽  
Electron Density ◽  
Laser Light ◽  
Line Emission ◽  
Argon Plasma ◽  
Stark Broadening ◽  
Excited Atoms ◽  
Electron Density Gradient ◽  
Transient Plasma ◽  
The Continuum

The interaction between a 20 MW Q-switched ruby laser pulse and a partially ionized argon plasma has been studied experimentally. When the focused laser pulse is fired into the plasma, a transient emission from the plasma may be observed both in the continuum and line emission. From measurements of the absolute intensities of this transient radiation, estimates have been made of the population density of the excited atoms and of the electron densities. The Stark broadening of the Ar II lines has also been measured to obtain the electron density in the transient plasma and data obtained in this way are consistent with those obtained from the continuum radiation. During the time when the laser light is incident on the plasma the Ar II lines show a strong asymmetry which disappears quickly after the laser pulse has terminated. This asymmetry can be explained in terms of the electron density gradient present in the expanding perturbed plasma.

scholarly journals Spectral Analysis of a White Light Flare

1989 ◽  
Vol 104 (2) ◽  
pp. 247-250
Author(s):  
Boyer R. ◽  
Sotirovski P.
Keyword(s):  
Spectral Analysis ◽  
Solar Flare ◽  
Electron Density ◽  
White Light ◽  
Time Profile ◽  
Crimean Astrophysical Observatory ◽  
Stark Broadening ◽  
Emission Mechanism ◽  
Measured Time ◽  
The Continuum

AbstractWe discuss observations of a solar flare located close to the limb (N15, W75) at 07 00 UT on 26 September 1963 from the Crimean Astrophysical observatory.Stark broadening and hence electron density have been obtained from measured time profile and half-width of the Baliner series lines from Hα to H M.The emission mechanism has been deduced from a study of the continuum intensity as a function of wavelength.

Excitation Temperatures and Electron Number Densities Experienced by Analyte Species in Inductively Coupled Plasmas with and without the Presence of an Easily Ionized Element

1977 ◽  
Vol 31 (2) ◽  
pp. 137-150 ◽  
Author(s):  
D. J. Kalnicky ◽  
V. A. Fassel ◽  
R. N. Kniseley
Keyword(s):  
Electron Density ◽  
Argon Plasma ◽  
Radial Excitation ◽  
Stark Broadening ◽  
Inductively Coupled Plasmas ◽  
Inductively Coupled ◽  
Density Distributions ◽  
Spatially Resolved ◽  
Density Values ◽  
Coupled Plasmas

Spatially resolved radial excitation temperatures and radial electron density distributions experienced by analyte species in the observation zone of 15 to 25 mm above the load coil of a toroidally shaped, inductively coupled argon plasma are presented and related to the analytical performance of these plasmas. A comparison of radial temperatures measured with support gas (Ar I) lines and with a typical analyte thermometric species (Pe I) at 15 mm above the load coil is given. Radial (Fe I) excitation temperatures obtained at three observation heights are compared for aerosol carrier flows of 1.0 and 1.3 liters/min. The addition of a large amount of an easily ionized element (6900 µg of Na per ml) did not significantly change Fe I excitation temperature distributions at the respective aerosol carrier flows and observation heights. A comparison of radial electron density distributions measured with Saha-Eggert ionization and with Stark broadening methods is given for an observation height of 15 mm above the load coil. The differences between electron density values obtained by these methods is discussed. The effect of addition of 6900 µg of Na per ml on Saha-Eggert electron density distributions at three observation heights is also discussed.

Bestimmung der Elektronenanzahldichte in einem Helium-Plasma / Determination of the Electron Density in a Helium Plasma

1976 ◽  
Vol 31 (3-4) ◽  
pp. 310-315
Author(s):  
D. Einfeld ◽  
G. Sauerbrey
Keyword(s):  
Electron Density ◽  
Helium Plasma ◽  
Emission Coefficient ◽  
Arc Plasma ◽  
Line Profiles ◽  
Stark Broadening ◽  
Peak Separation ◽  
Pulsed Arc ◽  
The Continuum

A comparison was made between electron densities determined from the emission coefficient of the continuum radiation and from Stark broadening of line profiles using a wall stabilized pulsed arc plasma with electron temperature T = 38 000 K and electron density from 2 × 1022 m−3 to 3.5 × 1022 m−3. The measured peak separation in the profiles of the He I lines 447.1 nm and 492.2 nm was consistent with that predicted by G.B.K.O.- and B.C.S.-theory and agrees with the experimental results from Bötticher, Roder, and Wobig. The measured halfwidth of the He I 501.6 nm line agrees with the results from Kusch and shows a discrepancy to the G.B.K.O.-theory by a factor about 1.7. The results for the Stark broadening halfwidth of the He II lines 468.6 nm and 320.3 nm lie between the values from G.K.S.-and K.G.-theory.

Stark broadening measurement of the electron density in an atmospheric pressure argon plasma jet with double-power electrodes

2010 ◽  
Vol 107 (6) ◽  
pp. 063303 ◽  
Author(s):  
Muyang Qian ◽  
Chunsheng Ren ◽  
Dezhen Wang ◽  
Jialiang Zhang ◽  
Guodong Wei
Keyword(s):  
Electron Density ◽  
Atmospheric Pressure ◽  
Argon Plasma ◽  
Plasma Jet ◽  
Stark Broadening ◽  
Argon Plasma Jet

scholarly journals Radial density profile and stability of capillary discharge plasma waveguides of lengths up to 40 cm

2021 ◽  
Vol 9 ◽  
Author(s):  
M. Turner ◽  
A. J. Gonsalves ◽  
S. S. Bulanov ◽  
C. Benedetti ◽  
N. A. Bobrova ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Electron Density ◽  
Density Profile ◽  
Pulse Propagation ◽  
Spot Size ◽  
Capillary Discharge ◽  
Electron Density Profile ◽  
Plasma Waveguide ◽  
Wakefield Acceleration ◽  
Plasma Wakefield

Abstract We measured the parameter reproducibility and radial electron density profile of capillary discharge waveguides with diameters of 650 $\mathrm{\mu} \mathrm{m}$ to 2 mm and lengths of 9 to 40 cm. To the best of the authors’ knowledge, 40 cm is the longest discharge capillary plasma waveguide to date. This length is important for $\ge$ 10 GeV electron energy gain in a single laser-driven plasma wakefield acceleration stage. Evaluation of waveguide parameter variations showed that their focusing strength was stable and reproducible to $<0.2$ % and their average on-axis plasma electron density to $<1$ %. These variations explain only a small fraction of laser-driven plasma wakefield acceleration electron bunch variations observed in experiments to date. Measurements of laser pulse centroid oscillations revealed that the radial channel profile rises faster than parabolic and is in excellent agreement with magnetohydrodynamic simulation results. We show that the effects of non-parabolic contributions on Gaussian pulse propagation were negligible when the pulse was approximately matched to the channel. However, they affected pulse propagation for a non-matched configuration in which the waveguide was used as a plasma telescope to change the focused laser pulse spot size.

scholarly journals Water maser and radio continuum emission towards IRAS 23139+5939

2007 ◽  
Vol 3 (S242) ◽  
pp. 180-181
Author(s):  
M. A. Trinidad ◽  
S. Curiel ◽  
J. M. Torrelles ◽  
L. F. Rodríguez ◽  
V. Migenes ◽  
...  
Keyword(s):  
Flux Density ◽  
Line Emission ◽  
The Other ◽  
Radio Continuum ◽  
High Mass ◽  
Continuum Emission ◽  
Maser Line ◽  
Water Masers ◽  
Water Maser ◽  
The Continuum

AbstractWe present simultaneous observations of continuum (3.5 and 1.3cm) and water maser line emission (1.3cm) carried out with the VLA-A toward the high-mass object IRAS 23139+5939. We detected two radio continuum sources at 3.5cm separated by 0”5 (~2400 AU), I23139 and I23139S. Based on the observed continuum flux density and the spectral index, we suggest that I23139 is a thermal radio jet associated with a high-mass YSO. On the other hand, based on the spatio-kinematical distribution of the water masers, together with the continuum emission information, we speculate that I23139S is also a jet source powering some of the masers detected in the region.

scholarly journals Populations of Hydrogen-like Atoms or Ions and Radio Recombination Lines (RRL's) Interpretation

2002 ◽  
Vol 199 ◽  
pp. 351-352
Author(s):  
N.I. Rovenskaya
Keyword(s):  
Thermal Radiation ◽  
Electron Density ◽  
Hii Regions ◽  
Kinetic Temperature ◽  
Line Radiation ◽  
Continuum Radiation ◽  
Radio Recombination Lines ◽  
The Continuum

The problem of non-LTE populations has been considered in terms of the departure coefficients ∂bn/∂n as functions of the kinetic temperature Te, the electron density Ne, the continuum radiation flow Ic and the ratios of IHnα, IHnβ, IHnδ and IHnε (the line radiation flows). The ratio of IHnα/IHnβ are sensitive to the thermal radiation from HII regions. Characterized by the relation of ∂2bn/∂n2 > 0, the populations are shown to be inhabited radiatively.

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