Dynamic response treatment of a burning fusion plasma

Wilhelmsson, H.; Gustavsson, H G

doi:10.1088/0031-8949/49/6/014

Cited by 6 publications

(3 citation statements)

References 14 publications

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“…respectively, whereas the heat and particle pinch effects, the "off-diagonal'' elements [12], have the forms D,(n, 7') = k,nT"-', (6) where a T , a,, k T , k , , 6 and IC are constants, where 6 = K = 312 for transport caused by pure ion temperature gradient driftwave turbulence. In eq.…”

Section: Coupled Equations Of Fusion Plasma Temperature Andmentioning

confidence: 99%

Fusion plasma dynamics governed by two mixed transport processes: ion temperature gradient driven drift-wave turbulence and resistive-ballooning mode turbulence

Wilhelmsson

Roux

1995

Phys. Scr.

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The influence on the dynamics of a fusion plasma of a contribution of resistive-ballooning mode turbulence -T-'I2 in addition to the temperature gradient driven dnft-wave turbulence in the transport coefficients is investigated. For the central part of the plasma the coupled equations for the evolution of temperature and density leads to the results that the high temperature stationary point which is stable, will be lowered as a consequence of the presence of the resistive-ballooning mode transport, whereas the low temperature stationary point which is unstable, and which exists for a bounded plasma in the presence of bremsstrahlung radiation losses, will occur at increased values of the temperature.

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Section: Coupled Equations Of Fusion Plasma Temperature Andmentioning

confidence: 99%

Fusion plasma dynamics governed by two mixed transport processes: ion temperature gradient driven drift-wave turbulence and resistive-ballooning mode turbulence

Wilhelmsson

Roux

1995

Phys. Scr.

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“…are specifically accounted for because of their interesting influence of resonances for e.g. a, = O h , where wh denotes the frequency of natural (free) oscillations of the system [homogeneous solutions of the linearized equations (1) and ( 2)]. For I, = -A k , I, being the natural damping rate of the free oscillations, the resonances become particularly pronounced.…”

Section: (10)mentioning

confidence: 99%

Simulation analysis of the dynamic response of burning fusion plasmas

Roux

Wilhelmsson

1994

Phys. Scr.

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The global dynamics of temperature and density in a fusion plasma is investigated by numerical simulation of coupled nonlinear (reactiondiffusion) partial differential equations. The simultaneous influence on the plasma behaviour of several dynamic processes, e.g. heat conduction and particle diffusion, heat and particle pinch effects, alpha particle heating as well as thermalization of the alpha particles is considered. Particular interest is paid to the influence of extended forms of the heat conduction and particle diffusion coefficients, motivated by experimental observations. It is shown that driven periodic perturbations in the transport and/or source coefficients may result in a plasma response, which exhibits a mixture of free (natural) and forced oscillations of a burning fusion plasma. The oscillations, which are generally nonlinear, refer to an equilibrium (stationary point) which is, however, never reached in the dynamic process, of evolution due to the presence of the driven periodic oscillations. The response caused by the driven perturbations instead remains after the natural oscillations have disappeared. The long term response as well as the characteristics of the separate free oscillations contain information about the source and transport coefficients. The simulations extend and confirm recent results of analytic model calculations (valid for the central domain of the plasma) which are useful for predicting and interpreting the global dynamic behaviour of the fusion plasma [l].

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“…by a change of external power deposition profile [7][8][9][10][11][12][13][14]. These properties are of great interest when considering the formation of equilibria of fusion plasmas as well as the stability of such equilibria, in fusion laboratory experiments and in the cosmos [20][21][22][23][24].…”

Section: Introductionmentioning

confidence: 99%

Fusion and the cosmos

Wilhelmsson¹

2004

Condens. Matter Phys.

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In the following investigation we pay special attention to the role of selforganization in fusion plasma physics and in the cosmos. We present a new approach to the expansion of the universe. Formally the technique developed relies on our experience from treating hot fusion plasmas. We account for the possibility that the universe, as it seems, could have a finite life-time (even if it is counted in billions of years), and combine this assumption with the experimental observation that the velocity of separation of distant galaxies is proportional to the distance between the galaxies (the Hubble law). By analysis of a NL PDE (nonlinear partial differential equation) we succed in proving that the crucial value of an exponent has a simple linear relationship with the Hubble constant. It is recognized that the scale-length that we use as a measure of the expansion is equivalent to the Einstein radius of curvature. The final results suggest that the Hubble law should be extended by a factor, which could have an explosive tendency of growth in time (open universe), or a decaying character (closed universe). The possibility of reversed expansion or an oscillating universe "cosmic pendulum" is also discussed.

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Dynamic response treatment of a burning fusion plasma

Cited by 6 publications

References 14 publications

Fusion plasma dynamics governed by two mixed transport processes: ion temperature gradient driven drift-wave turbulence and resistive-ballooning mode turbulence

Fusion plasma dynamics governed by two mixed transport processes: ion temperature gradient driven drift-wave turbulence and resistive-ballooning mode turbulence

Simulation analysis of the dynamic response of burning fusion plasmas

Fusion and the cosmos

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