scholarly journals Experimental study of layer mixing, relative ionic escape velocity, and electron temperature gradients in spherical multilayered targets by XUV spectroscopy

1990 ◽  
Author(s):  
H.R. Griem
Keyword(s):  
Experimental Study ◽  
Electron Temperature ◽  
Temperature Gradients ◽  
Escape Velocity ◽  
Electron Temperature Gradients ◽  
Xuv Spectroscopy

scholarly journals The Chemical Features of Galactic Planetary Nebulae

1993 ◽  
Vol 155 ◽  
pp. 575-575
Author(s):  
P. R. Amnuel
Keyword(s):  
Chemical Composition ◽  
Electron Temperature ◽  
Planetary Nebulae ◽  
Temperature Gradients ◽  
Element Abundances ◽  
Electron Temperature Gradients ◽  
The Masses ◽  
Progenitor Stars

The chemical composition of 218 galactic planatary nebulae is investigated, all the nebulae are divided into four classes according to the masses of the nebulae and progenitor stars. The values of local abundances, galactic abundances and electron temperature gradients are found for each class of nebulae. The correlations between element abundances are also investigated. The results are compared with theorical predictions.

scholarly journals Enhanced ion acoustic fluctuations and ion outflows

1999 ◽  
Vol 17 (2) ◽  
pp. 182-189 ◽  
Author(s):  
F. R. E. Forme ◽  
D. Fontaine
Keyword(s):  
Electron Temperature ◽  
Temperature Gradients ◽  
Spectral Signature ◽  
Simultaneous Occurrence ◽  
Plasma Parameters ◽  
Strong Electron ◽  
Ion Drift ◽  
Incoherent Scatter ◽  
Ion Acoustic ◽  
Electron Temperature Gradients

Abstract. A number of observations showing enhanced ion acoustic echoes observed by means of incoherent scatter radars have been reported in the literature. The received power is extremely enhanced by up to 1 or 2 orders of magnitude above usual values, and it is mostly contained in one of the two ion acoustic lines. This spectral asymmetry and the intensity of the received signal cannot be resolved by the standard analysis procedure and often causes its failure. As a result, and in spite of a very clear spectral signature, the analysis is unable to fit the plasma parameters inside the regions of ion acoustic turbulence. We present European Incoherent Scatter radar (EISCAT) observations of large ion outflows associated with the simultaneous occurrence of enhanced ion acoustic echoes. The ion fluxes can reach 1014 m-2 s-1 at 800 km altitude. From the very clear spectral signatures of these echoes, a method is presented to extract estimates of the electron temperature and the ion drift within the turbulent regions. It is shown that the electron gas is strongly heated up to 11 000 K. Also electron temperature gradients of about 0.02 K/m exist. Finally, the estimates of the electron temperature and of the ion drift are used to study the possible implications for the plasma transport inside turbulent regions. It is shown that strong electron temperature gradients cause enhancement of the ambipolar electric field and can account for the observed ion outflows.Key words. Ionosphere (auroral ionosphere; ionosphere · magnetosphere interactions; plasma waves and instabilities).

Experimental Study of a Plasma Produced by a Helical Radio-frequency Structure

1974 ◽  
Vol 52 (22) ◽  
pp. 2246-2249 ◽  
Author(s):  
H. W. H. Van Andel ◽  
M. T. Churchland ◽  
G. Calabrese
Keyword(s):  
Magnetic Field ◽  
Experimental Study ◽  
Field Strength ◽  
Electron Temperature ◽  
Magnetic Field Strength ◽  
Cyclotron Resonance ◽  
Electron Cyclotron Resonance ◽  
Plasma Stability ◽  
Absorption Process ◽  
Moderate Power

A plasma produced by a helical RF structure of the Lisitano type is investigated. Measurements of electron density, electron temperature, and plasma stability are reported as a function of RF frequency and power, magnetic field strength and geometry, and neutral argon pressure. It is concluded that at moderate power (~20 W), electron cyclotron resonance is important in the power absorption process.

EXPERIMENTAL STUDY OF PLATE BUCKLING INDUCED BY SPATIAL TEMPERATURE GRADIENTS

1994 ◽  
Vol 17 (2) ◽  
pp. 191-212 ◽  
Author(s):  
Earl A. Thornton ◽  
Marshall F. Coyle ◽  
Rory N. McLeod
Keyword(s):  
Experimental Study ◽  
Temperature Gradients ◽  
Plate Buckling ◽  
Spatial Temperature

scholarly journals Experimental study of radiative shocks at PALS facility

2010 ◽  
Vol 28 (2) ◽  
pp. 253-261 ◽  
Author(s):  
Chantal Stehlé ◽  
Matthias González ◽  
Michaela Kozlova ◽  
Bedrich Rus ◽  
Tomas Mocek ◽  
...  
Keyword(s):  
Experimental Study ◽  
High Energy ◽  
T Tauri Stars ◽  
Rear Side ◽  
Iodine Laser ◽  
Radiative Shocks ◽  
T Tauri ◽  
Long Time ◽  
Xuv Spectroscopy ◽  
Spectroscopic Signatures

AbstractWe report on the investigation of strong radiative shocks generated with the high energy, sub-nanosecond iodine laser at PALS. These shock waves are characterized by a developed radiative precursor and their dynamics is analyzed over long time scales (~50 ns), approaching a quasi-stationary limit. We present the first preliminary results on the rear side XUV spectroscopy. These studies are relevant to the understanding of the spectroscopic signatures of accretion shocks in Classical T Tauri Stars.

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