Boris B. Kadomtsev

Reviews of plasma physics

Mechanisms of transverse conductivity and generation of self-consistent electric fields in strongly ionized magnetized plasma V. Rozhansky. 1. Introduction.- 2. Conductivity tensor in partially ionized plasma.- 3. Main mechanisms of perpendicular conductivity in fully ionized plasma.- 4. Acceleration of plasma clouds in an inhomogeneous magnetic field.- 5. Alfven conductivity.- 6. Perpendicular viscosity, radial current, and radial electric field in an infinite cylinder.- 7. Current systems in front of a biased electrode (flush-mounted probe) and spot of emission.- 8. Currents in the vicinity of a biased electrode that is smaller than the ion gyroradius.- 9. Neoclassical perpendicular conductivity in a tokamak.- 10. Transverse conductivity in a reversed field pinch.- 11. Modeling of electric field and currents in the tokamak edge plasma.- 12. Mechanisms of anomalous perpendicular viscosity and viscosity-driven currents.- 13. Transverse conductivity in a stochastic magnetic field.- 14. Electric fields generated in the shielding layer between hot plasma and a solid state.-- Correlations and anomalous transport models O.G. Bakunin. 1. Introduction.- 2. Turbulent diffusion and transport.- 3. Non-local effects and diffusion equations.- 4. The Corrsin conjecture.- 5. Effects of seed diffusivity.- 6. The diffusive tracer equation and averaging.- 7. The quasi-linear approximation.- 8. The diffusive renormalization.- 9. Anomalous transport and convective cells.- 10. Stochastic instability and transport.- 11. Fractal conceptions and turbulence.- 12. Percolation and scalings.- 13. Percolation and turbulent transport scalings.- 14. The temporal hierarchy of scales and correlations.- 15. The stochastic magnetic field and percolation transport.- 16. Percolation in drift flows.- 17. Multiscale flows.- 18. Subdiffusion and traps.- 19. Continuous time random walks.- 20. Fractional differential equations and scalings.- 21. Correlation and phase-space.- 22. Conclusion.

TRAPPED PARTICLES IN TOROIDAL MAGNETIC SYSTEMS.

The review is devoted to the discussion of the role of trapped particles for equilibrium, diffusion and stability of plamas in toroidal magnetic devices. The motion of single particles in a toroidal magnetic field, the neoclassical transport processes due to the trapping of particles and trapped-particle instabilities in toroidal geometry are discussed. The correspondence between the neoclassical theory of diffusion, the turbulent transport processes due to the instabilities and the existing experimental Tokamak data is discussed.

Non-linear phenomena in tokamak plasmas

A tokamak is the simplest magnetic configuration for the confinement of high temperature plasma bearing in mind its subsequent use for nuclear fusion reactors. A tokamak looks like a vacuum toroidal chamber with magnetic coils. This chamber is filled by hydrogen (or hydrogen isotopes) gas, at low pressure. Then with the help of an induced azimuthal electric field a toroidal discharge is excited which heats the plasma up to very high temperature. Additional heating can be used to further increase the plasma temperature and to reach hundreds of millions . A toroidal magnetic field is used to suppress plasma instabilities. The concept itself is a simple one but the behaviour of high temperature plasmas in tokamaks has turned out to be very complicated. A lot of non-linear processes develop in the plasma. Some of them are similar to the usual hydromagnetic turbulence. But this turbulence coexists with many coherent structures strongly coupled with each other. Step by step the physics of many cooperative effects in tokamak plasmas have been successfully clarified. They are discussed in this review both from a experimental and a theoretical point of view. This review was received December 1994

Turbulent convection of plasma in a magnetic field

In this work, the known analogy between the convection instability of a normal liquid and one of the most dangerous forms of plasma instability in a magnetic field – the so-called convective, or commutation instability is extended to include the non-linear flows arising as a consequence of instability. In the first section, the turbulent convection of a plasma in traps with magnetic mirrors and in a discharge, with a longitudinal field of moderate strength, is examined. An explanation is furnished in this way of a mtmber of peculiarities in the behaviour of a plasma in experimental devices of this type. The second section deals with convection arising in a plasma in the presence of a longitudinal current. It is shown, that on the basis of the current convection mechanism, it is possible to explain the anomalous,diffusion of plasma in a positive column.

Plasma Physics and Controlled Nuclear Fusion Research (Report on the 9th IAEA International Conference, Baltimore, 1982)

During the past decade of IAEA Conferences on controlled fusion research, the topic of principal interest has shifted from the feasibility of fusion power to the optimization of economically favourable reactor characteristics: efficient plasma heating systems, high beta values, quasi-steady-state operating capabilities, simple coil structures, etc. At the present Conference, the experimental tokamak papers (about half the total number of papers in the category of magnetic-confinement experiments) offer a striking illustration of this trend. The other approaches – tandem mirrors, EBTs, stellarators, reversed-field pinches, and compact tori (represented in roughly equal numbers) – are still confronting questions of basic feasibility, but their research programmes are also becoming oriented towards particular features of reactor attractiveness.

Conference Report on Plasma Physics and Controlled Nuclear Fusion Research

In summarizing the results of this Conference, the first fact we note is that transition to toroidal machines is nearly complete now in both high- and low-β physics, with one exception, – the mirror machines.

Viktor Mikhailovich Gusev

V. M. Gusev was born in 1919. In October 1941 he volunteered for the front while a third-year student in the physics department of Moscow State University. Before going into action, he joined the Communist Party of the Soviet Union. He was seriously wounded during fighting near Leningrad but after a long convalescence he returned to duty and fought until victory. He was decorated with the Order of the Great Patriotic War and manymedals. When the war ended he returned to Moscow State University and graduated.

Cross-Field Thermal Conduction and Transport: Report on the IAEA Advisory Group Meeting, Kiev, Ukrainian SSR, USSR, 21–25 November 1977

The IAEA Advisory Group Meeting on Cross-Field Thermal Conduction and Transport was held in Kiev, Ukrainian SSR, 21 to 25 November 1977. At the Meeting, the present status and prospects for understanding transport in magnetically confined plasmas were discussed. The Meeting was convened on the initiative of the International Fusion Research Council of the IAEA and organized by the Institute for Nuclear Research of the Ukrainian Academy of Sciences. Twenty-two participants from eight countries (ten from USA, three from UK, three from France, two from Japan and one each from FRG, Belgium, Netherlands and Sweden) came to Kiev to meet with fourteen participants and twenty observers from the USSR.

Fourth International Conference on Plasma Physics and Controlled Nuclear Fusion Research (Report on the Conference, Madison, Wisconsin, USA 17-23 June 1971)

The Fourth International Conference on Plasma Physics and Controlled Nuclear Fusion Research, organized by the International Atomic Energy Agency, was held during the summer of this year in the United States of America - in the small university town of Madison, in the state of Wisconsin. Some 500 scientists from about 30 countries took part in the Conference and approximately 140 papers were discussed, considerable use having been made of the rapporteur system. As at the earlier conferences in this series, most of the papers described experimental work.