Energy Confinement in Self-Organized Tokamak Plasma (without Transport Barriers)

2020 ◽  
Vol 46 (4) ◽  
pp. 337-348
Author(s):  
K. A. Razumova ◽  
M. M. Dremin ◽  
N. V. Kasyanova ◽  
N. A. Kirneva ◽  
L. A. Klyuchnikov ◽  
...  
Keyword(s):  
Tokamak Plasma ◽  
Energy Confinement ◽  
Self Organized ◽  
Transport Barriers

scholarly journals Explanation of Experimentally Observed Phenomena in Hot Tokamak Plasmas from the Nonequilibrium Thermodynamics Position

Entropy ◽  
2019 ◽  
Vol 22 (1) ◽  
pp. 53
Author(s):  
Ksenia A. Razumova ◽  
Valerii F. Andreev ◽  
Nadezhda V. Kasyanova ◽  
Sergey E. Lysenko
Keyword(s):  
Nonequilibrium Thermodynamics ◽  
Plasma Heating ◽  
Tokamak Plasma ◽  
Magnetic Islands ◽  
Energy Confinement ◽  
Tokamak Reactor ◽  
Plasma Energy ◽  
Radiation Losses ◽  
Transport Barriers ◽  
Internal Transport Barriers

In studying the hot plasma behavior in tokamak devices, the classical approach for collisional processes is traditionally used. This approach leaves unexplained a number of phenomena observed in experiments related to plasma energy confinement. Further, it is well known that tokamak plasma is always turbulent and self-organized. In the present paper, we show that the nonequilibrium thermodynamics approach allows us to explain many observed dependences and paradoxes; for example, puffing of impurities results in confinement improvement if zones of plasma cooling by impurities and additional plasma heating are not overlapped. The analysis of the experimental results shows the important role of radiation losses at the plasma edge in the processes determining its total energy confinement. It is shown that the generally accepted dependence of energy confinement on plasma density is not quite adequate because it is a consequence of dependence on radiation losses. The phenomenon of the appearance of internal transport barriers and magnetic islands can also be explained by plasma self-organization. The obtained results may be taken into account when calculating the operation of a future tokamak reactor.

Self-Organized Criticality Processes in HL-1M Tokamak Plasma

2002 ◽  
Vol 20 (1) ◽  
pp. 87-89 ◽  
Author(s):  
Huang Yuan ◽  
Qiu Xiao-Ming ◽  
Ding Xuan-Tong ◽  
Wang En-Yao
Keyword(s):  
Tokamak Plasma ◽  
Self Organized ◽  
Self Organized Criticality

Self-organized criticality revisited: non-local transport by turbulent amplification

2015 ◽  
Vol 81 (6) ◽  
Author(s):  
A. V. Milovanov ◽  
J. J. Rasmussen
Keyword(s):  
Real Space ◽  
Magnetized Plasma ◽  
Tokamak Plasma ◽  
Growth Time ◽  
Strong Nonlinearity ◽  
Inverse Cascade ◽  
Self Organized ◽  
Self Organized Criticality ◽  
Non Local ◽  
Local Transport

We revise the applications of self-organized criticality (SOC) as a paradigmatic model for tokamak plasma turbulence. The work, presented here, is built around the idea that some systems do not develop a pure critical state associable with SOC, since their dynamical evolution involves as a competing key factor an inverse cascade of the energy in reciprocal space. Then relaxation of slowly increasing stresses will give rise to intermittent bursts of transport in real space and outstanding transport events beyond the range of applicability of the ‘conventional’ SOC. Also, we are concerned with the causes and origins of non-local transport in magnetized plasma, and show that this type of transport occurs naturally in self-consistent strong turbulence via a complexity coupling to the inverse cascade. We expect these coupling phenomena to occur in the parameter range of strong nonlinearity and time scale separation when the Rhines time in the system is small compared with the instability growth time.

Experimental evidence for self-organized criticality in tokamak plasma turbulence

1999 ◽  
Vol 253 (3-4) ◽  
pp. 181-186 ◽  
Author(s):  
T.L. Rhodes ◽  
R.A. Moyer ◽  
R. Groebner ◽  
E.J. Doyle ◽  
R. Lehmer ◽  
...  
Keyword(s):  
Experimental Evidence ◽  
Plasma Turbulence ◽  
Tokamak Plasma ◽  
Self Organized ◽  
Self Organized Criticality

On energy confinement following the onset of ‘stiff’ transport

2020 ◽  
Vol 86 (2) ◽  
Author(s):  
J. W. Connor ◽  
R. J. Hastie ◽  
K. Richards
Keyword(s):  
Temperature Profile ◽  
Power Loss ◽  
Fusion Reactor ◽  
Input Power ◽  
Tokamak Plasma ◽  
Energy Confinement ◽  
The Core ◽  
Core Energy

The dependence of confinement on input power for a tokamak plasma with regions having a stiff temperature profile is explored. The resilience of the confinement of the core energy to increasing power loss by core radiation from impurities in such situations, as it is anticipated will be required in a demonstration fusion reactor (DEMO) design, is examined.

Problem behavior in autism spectrum disorders: A paradigmatic self-organized perspective of network structures

2019 ◽  
Vol 42 ◽  
Author(s):  
Lucio Tonello ◽  
Luca Giacobbi ◽  
Alberto Pettenon ◽  
Alessandro Scuotto ◽  
Massimo Cocchi ◽  
...  
Keyword(s):  
Autism Spectrum Disorder ◽  
Problem Behaviors ◽  
Autism Spectrum ◽  
The Self ◽  
Network Structures ◽  
Self Organized ◽  
Critical Equilibrium ◽  
Self Organized Criticality ◽  
Acute Agitation ◽  
Spectrum Disorders

AbstractAutism spectrum disorder (ASD) subjects can present temporary behaviors of acute agitation and aggressiveness, named problem behaviors. They have been shown to be consistent with the self-organized criticality (SOC), a model wherein occasionally occurring “catastrophic events” are necessary in order to maintain a self-organized “critical equilibrium.” The SOC can represent the psychopathology network structures and additionally suggests that they can be considered as self-organized systems.

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