Large Tokamak Experiments (Report on the IAEA Technical Committee Meeting, Dubna, 1975)

Abstract

There are four large next-generation tokamak devices presently being designed. These are:(1) the JET (Joint European Torus) project sponsored by the Commission of the European Communities in association with EURATOM, (2) the TCT (Two-Component Torus) project underway in the United States of America, (3) the JT-60 (Japan-Tokamak) project of Japan and the T-20 tokamak project of the Union of Soviet Socialist Republics. The meeting held in Dubna provided an opportunity for leading members of the various projects to discuss the scientific objectives and detailed design features of each device, with the hope that an informal exchange of information on what each team was trying to do and how it was going about it could lead to some useful co-ordination of effort and avoidance of duplicate effort. The timing of the meeting was such that any resulting design modifications could yet be incorporated into present designs, even in the most advanced of the projects.The first two days of the meeting were devoted to detailed descriptions of the major characteristics of each machine and its sub-systems, and the reasons for the design approaches adopted. A brief summary of the four projects is given below, as prepared by B. B. Kadomtsev, General Chairman of the conference. Included is a table giving a combined list of design parameters. More detailed descriptions of the four tokamak projects are given in Annexes I, II, III and IV.Four days of the meeting were given over to workshop-type sessions on various component systems and selected problem areas. These discussions covered: A. Power supplies and control systems; B. Vacuum systems; C. Magnet systems; D. Plasma considerations; E. Cost scaling; F. Superconducting magnet systems; G. Diagnostics; H. Radiation shielding and remote handling; I. Conceptual fusion reactor designs and J. Possibilities for hybrid reactors. Resumes of these discussions, as prepared by each of the session chairmen, are given in this report. Approximately 100 specialists took part in the meeting, including 18 from countries of Western Europe, 8 from Japan, 15 from the USA, and 54 from the USSR. Arrangements were made for a visit of the tokamak facilities at the Kurchatov Institute in Moscow, including the newly completed T-10 device. BRIEF SUMMARY OF THE FOUR PROJECTS (B. B. Kadomtsev) 24 Circular 1.94 1.8x10' at the W6Q&Q 230 350 ±0.05 +6.0 ±15 Air Oore * 2.25 # Mag,Limiter. horiz. H e l d * quad, field coili • 130 * * >ower Grid & **

Electron-cyclotron heating of plasma in toroidal systems

“…An ordinary wave injected from the outside will reach the zone of cyclotron resonance if the gyrofrequency exceeds the plasma frequency a> H > co p at the centre of the plasma column. The latter condition is fulfilled for the majority of existing and projected tokamaks [5]. Moreover, as will be shown below (see also Ref.…”

Equilibrium of a plasma column in an octopole tokamak without conducting shell

“…The above discussion is applicable to the special case where the plasma column is located above the meridian plane. In an ordinary discharge, the plasma column is located on the meridian plane and the displacement of the column in the Z direction shown in the locus (1) is not observable. When the plasma column is located at R = 28-29 cm, the increasing rate of the plasma current is maximum and decreases for R >, 30 cm.…”

“…Various methods of high-temperature, highdensity plasma confinement have been proposed in many countries in order to realize controlled thermonuclear fusion. Among them, the device using Tokamak-type field is most promising and large-scale facilities of this type have been constructed [ 1 ].…”

Neutral-beam-injected tokamak fusion reactors: a review

“…A number of large tokamaks proposed for completion in the period 1981-1984 [181] are intended to bridge the. gap between present plasma physics experiments (including those of Table 8) and full-fledged reactors.…”

“…The design parameters of all these machines as of July 1975 are summarized in Ref. [181]. In each case the use of copper toroidal-field coils dictates modest duty factors'<-1%).…”