A one‐dimensional model for radiative thermal equilibrium and stability of the tokamak edge plasma

1994 ◽  
Vol 1 (1) ◽  
pp. 127-131 ◽  
Author(s):  
Shishir Deshpande
Keyword(s):  
Thermal Equilibrium ◽  
Edge Plasma ◽  
Dimensional Model ◽  
One Dimensional ◽  
Tokamak Edge

The action of Vlasov waves on the velocity distribution in a plasma

1961 ◽  
Vol 10 (3) ◽  
pp. 473-479 ◽  
Author(s):  
J. W. Dungey
Keyword(s):  
Magnetic Field ◽  
Phase Space ◽  
Velocity Distribution ◽  
Thermal Equilibrium ◽  
Limited Range ◽  
Dimensional Model ◽  
One Dimensional ◽  
A Current

A one-dimensional model with no magnetic field is considered. It is supposed that the plasma starts in thermal equilibrium and then a current is forced to grow. Instability leads to the growth of waves, which are shown to stir the distribution in phase space, but only over a limited range of velocity. It is concluded that in order to restore stability the energy in the wave must become comparable to the energy of drift.

Modelling Techniques in Applied Glaciology: Numerical Modelling of Avalanches

1983 ◽  
Vol 4 ◽  
pp. 297-297
Author(s):  
G. Brugnot
Keyword(s):  
Finite Difference Method ◽  
Transverse Velocity ◽  
Longitudinal Velocity ◽  
Momentum Conservation ◽  
Dimensional Model ◽  
One Dimensional ◽  
Modelling Techniques ◽  
Reference Grid ◽  
The One ◽  
Near Future

We consider the paper by Brugnot and Pochat (1981), which describes a one-dimensional model applied to a snow avalanche. The main advance made here is the introduction of the second dimension in the runout zone. Indeed, in the channelled course, we still use the one-dimensional model, but, when the avalanche spreads before stopping, we apply a (x, y) grid on the ground and six equations have to be solved: (1) for the avalanche body, one equation for continuity and two equations for momentum conservation, and (2) at the front, one equation for continuity and two equations for momentum conservation. We suppose the front to be a mobile jump, with longitudinal velocity varying more rapidly than transverse velocity.We solve these equations by a finite difference method. This involves many topological problems, due to the actual position of the front, which is defined by its intersection with the reference grid (SI, YJ). In the near future our two directions of research will be testing the code on actual avalanches and improving it by trying to make it cheaper without impairing its accuracy.

Issues of TOKAMAK Edge Plasma Transport and Plasma-material Interactions

2015 ◽  
Vol 6 (1-2) ◽  
pp. 86-91
Author(s):  
S. I. Krasheninnikov ◽  
J. Guterl ◽  
W. Lee ◽  
R. D. Smirnov ◽  
E. D. Marenkov ◽  
...  
Keyword(s):  
Edge Plasma ◽  
Plasma Transport ◽  
Tokamak Edge ◽  
Plasma Material Interactions

scholarly journals Undecidability in quantum thermalization

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Naoto Shiraishi ◽  
Keiji Matsumoto
Keyword(s):  
Turing Machine ◽  
Thermal Equilibrium ◽  
General Theorem ◽  
Nearest Neighbour ◽  
Many Body ◽  
Initial State ◽  
One Dimensional ◽  
Universal Turing Machine ◽  
Many Body Systems ◽  
Neighbour Interaction

AbstractThe investigation of thermalization in isolated quantum many-body systems has a long history, dating back to the time of developing statistical mechanics. Most quantum many-body systems in nature are considered to thermalize, while some never achieve thermal equilibrium. The central problem is to clarify whether a given system thermalizes, which has been addressed previously, but not resolved. Here, we show that this problem is undecidable. The resulting undecidability even applies when the system is restricted to one-dimensional shift-invariant systems with nearest-neighbour interaction, and the initial state is a fixed product state. We construct a family of Hamiltonians encoding dynamics of a reversible universal Turing machine, where the fate of a relaxation process changes considerably depending on whether the Turing machine halts. Our result indicates that there is no general theorem, algorithm, or systematic procedure determining the presence or absence of thermalization in any given Hamiltonian.

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