scholarly journals Solutions and reductions for radiative energy transport in laser-heated plasma

2015 ◽  
Vol 56 (1) ◽  
pp. 011503 ◽  
Author(s):  
P. Broadbridge ◽  
N. M. Ivanova
Keyword(s):  
Energy Transport ◽  
Radiative Energy ◽  
Radiative Energy Transport ◽  
Laser Heated

Radiative Energy Transport

2021 ◽  
pp. 73-83
Author(s):  
Tianshu Liu ◽  
John P. Sullivan ◽  
Keisuke Asai ◽  
Christian Klein ◽  
Yasuhiro Egami
Keyword(s):  
Energy Transport ◽  
Radiative Energy ◽  
Radiative Energy Transport

Buoyancy-driven flows of a radiatively participating fluid in a vertical cylinder heated from below

1993 ◽  
Vol 442 (1915) ◽  
pp. 313-341 ◽  
Keyword(s):  
Rayleigh Number ◽  
Energy Transport ◽  
Vertical Cylinder ◽  
Side Wall ◽  
Radiative Energy ◽  
Parameter Study ◽  
Internal Radiation ◽  
Static State ◽  
Buoyancy Driven Flows ◽  
Radiative Energy Transport

The effect of radiative energy transport on the onset and evolution of natural convective flows is studied in a Rayleigh–Bénard system. Steady, axisymmetric flows of a radiatively participating fluid contained in a rigid-walled, vertical cylinder which is heated on the base, cooled on top, and insulated on the side wall are calculated by using the Galerkin finite element method. Bifurcation analysis techniques are used to investigate the changes in the flow structure due to internal radiation. The results of this two-parameter study – where the Rayleigh number, Ra and optical thickness, ז , are varied – apply to fluids ranging from opaque to nearly transparent with respect to infrared radiation. For any non-opaque fluid, internal radiation eliminates the static state that, without radiation, exists for all values of the Rayleigh number. This heat transfer mechanism also destroys a symmetry of the system that relates clockwise and counter-clockwise flows. The connectivity between characteristic flow families and the range of Ra where families are stable are found to depend greatly on ז . Results demonstrate the inadequacy of characterizing the behaviour of this system using simple notions of radiative transfer in optically thick or thin media; the nonlinear interaction of radiation and flow are far more complicated than these asymptotic limits would imply.

scholarly journals Experiments with laser-irradiated cylindrical targets

1991 ◽  
Vol 9 (3) ◽  
pp. 725-747 ◽  
Author(s):  
C. Stöckl ◽  
G. D. Tsakiris
Keyword(s):  
Light Propagation ◽  
Energy Transport ◽  
Laser Light ◽  
Laser Energy ◽  
Axial Direction ◽  
Radiative Energy ◽  
Capillary Length ◽  
Inner Diameter ◽  
Laser Heated ◽  
Good Agreement

Results of novel experiments with laser-heated capillary targets are presented. In these experiments the interior of gold capillaries having a 200- or 700-μm inner diameter and a 2–12-mm length was axially irradiated by injection of the laser energy through one of the end openings. A frequency-doubled Nd:glass laser (λ = 0.53 μm) was employed, delivering 8-J energy in 3 ns. The experiments showed no significant backreflection of laser light. Depending on the capillary diameter and length, most of the laser energy is either transmitted or absorbed inside the capillary. The transmission of laser light was measured as a function of capillary length and found to be in good agreement with the predictions of a simple theoretical model. Two extreme cases could be identified. Capillaries with a 700-μm diameter show uninhibited laser light propagation due to multireflections off the inner wall. In contrast, at the entrance of capillaries with a 200-μm inner diameter a plasma plug forms that absorbs most of the laser energy. In both cases significant energy transport was observed to occur in the axial direction. A stable and strongly radiating plasma column is formed along the capillary axis by the collision of the radially imploding plasma. During the collision, part of the hydrodynamic energy of the plasma is converted into radiative energy. In a special case-a lower limit of ≊7% could be inferred for the conversion efficiency from laser light into X-ray radiation emitted from the rear opening of the capillary.

scholarly journals Model Calculations of the Photospheric Layers of Solar Magnetic Fluxtubes

1990 ◽  
Vol 138 ◽  
pp. 181-184 ◽  
Author(s):  
Oskar Steiner ◽  
J.O. Stenflo
Keyword(s):  
Observational Data ◽  
Empirical Model ◽  
Energy Transport ◽  
Rotational Symmetry ◽  
Radiative Energy ◽  
Model Calculations ◽  
Density Reduction ◽  
Radiative Energy Transport ◽  
Semi Empirical

Multi-dimensional radiative energy transport is coupled self-consistently to magnetohydrostatic solutions for fluxtubes with rotational symmetry. It is shown that the photospheric layers of plage and network fluxtubes are heated by radiation by as much as 300 K at equal geometrical height. The amount of heating depends on the density reduction within the tube. The results are compared with observational data and the most recent semi-empirical model.

scholarly journals Experimental evidence of ionization burnthrough and absorption resonance in radiative energy transport in hot dense matter

1987 ◽  
Vol 36 (7) ◽  
pp. 3279-3287 ◽  
Author(s):  
T. Mochizuki ◽  
K. Mima ◽  
N. Ikeda ◽  
R. Kodama ◽  
H. Shiraga ◽  
...  
Keyword(s):  
Experimental Evidence ◽  
Energy Transport ◽  
Dense Matter ◽  
Radiative Energy ◽  
Absorption Resonance ◽  
Radiative Energy Transport
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