Eighth International Conference on Plasma Physics
Brussels, 1-10 July 1980

Origin and Role of International Cooperation in Fusion Research

Commission of the European Communities,

Your Majesty, Ladies and Gentlemen:

When the Director General of the International Atomic Energy Agency honored me by asking me to give the second Artsimovich Memorial Lecture at the beginning of this Eighth International Conference on Plasma Physics and Controlled Nuclear Fusion Research, three factors -- the nature of the subject, my own position and the vocation of the city of Brussels -- prompted me to give a short review of the origin and role of international cooperation in the evolution of fusion research. To do this I shall use as points of reference the previous conferences, and three of them in particular: the ;'avant-premiere', Geneva 1958, the Third, Novosibirsk 1968, and the Seventh, Innsbruck 1978. I feel that this is appropriate because these conferences, and especially the first few, gave us the opportunity to become acquainted and gave me, in particular, the first opportunity to meet Artsimovich, and also because they gave birth to this world-wide cooperation of which Artsimovich was one of the first proponents and one of the principal motive forces.

In Geneva the scenario was already established. There was enthusiasm for the enormous importance and of the task, which contained the promise of production of almost unlimited power in relatively clean and safe conditions. The diagnosis was quite precise: enormous difficulties would have to be overcome, both scientific, identified by many authors, and technical, identified mainly by Teller. The scientific difficulties derived from, among other things, the very nature of high-temperature plasma problems: equilibrium, stability, heating, impurities, etc., are so strictly interconnected that the classical procedure for solving scientific problems, i.e. to separate them in order to solve them one by one could not be applied. But the means for going ahead were already present in Geneva. Many possible confinement schemes were already at different levels of development: magnetic mirrors, Astron, the stellarators, tokamaks, linear and toroidal pinches and, among others, the British Zeta which was then producing the first results in its long experimental life.

'Theoretical bases were also available; for example, the Kruskal-Shafranov limitation, now so familiar to all plasma physicists.

'The prognosis concerning the time required to reach our goals became less definite, more severe: the twenty years mentioned three years earlier by Bhabha looked too optimistic now that the difficulties were more evident. As Artsimovich was to say so picturesquely three years later in Salzburg, the thermonuclear paradise could not be reached without a long journey through purgatory.

There was also considerable convergence on the prescription: it was impossible at that time to give precedence to one of the possible confinement schemes and so it was recommeuded to go ahead on a wide front, although Artsimovich foresaw that the low beta equilibria approach had some chance of maturing earlier.

A wide front implied an enormous amount of work, and to face this problem many participants, and more especially Artsimovich, recognized that world-wide cooperation was more than a means to make the task easier: it was an essential condition for ultimate success.

A first practical application of this recommendation took place in Europe, for reasons not only scientific and technical but also to some extent institutional. The same year (1958) saw the creation of Euratom, in whose programme fusion was already included. Considering both the possible advantage of fusion for Europe and the enormous difficulties to be solved for its realization, we decided to create a single European programme combining the activities of the different Member States of which there were at that time six and later nine. The concept on which this operation was based were the following:

  • Distribution of the activities among the various laboratories, avoiding unnecessary repetition and overlapping;
  • 'To encourage and facilitate the circulation of ideas and personnel, and when possible the sharing of experimental apparatus;
  • 'The concerted preparation of future programmes, the duration of which, according to the Euratom Treaty, could not exceed five years.

    Official recognition of this collective spirit is contained in the decision of the Council of Ministers of the European Communities, which states that each of these five-year programmes "is part of a long-term cooperative project embracing all work carried out in the Member States in the field of controlled thermonuclear fusion and designed to lead in due course to the joint construction of prototypes with a view to their industrial-scale production and marketing".

    lt is not for me to judge whether the system has been successful, but let me quote two facts:

    Two European countries, non-members of the European Community (Sweden and Switzerland), have found the system attractive enough to join it;

    When the opportunity arose to prepare a large project (now called JET) which, because of its size, exceeded the capacity of each individual Member State, the existence of a European structure made it possible to undertake the preliminary studies and subsequently the detailed design with a speed and efficiency which have no precedent - in Europe, at least.

    In the field of fusion the European programme represents the first supra-national structure which has made a sizable contribution to scientific and technical progress. If I am emphatic about this fact it is because I think that this model could be extended, with the modifications imposed by history and geography.

    An additional merit of this European collaboration was that it helped us to overcome the depression in fusion which was being felt in the 1960s. The end of this depression can be identified with the Third Fusion Conference, at Novosibirsk in 1968, which saw the successful emergence of the tokamak concept which had been outlined by Sakharov in 1951 and developed at the Kurchatov Institute (Moscow) under Artsimovich's personal direction. At Novosibirsk the outlook remained cautious, but began to be based on more solid ground. With regard to the predicted time scale, I can recall the conclusion of Budker that this would depend on the speed with which we could go ahead, and this in turn would be determined not only by the scientists but also by public authorities. Once again, international cooperation was regarded as an essential instrument.

    The next few years saw an enormous development of this collaboration, which now was motivated by the existence - or at least the prospect - of great scientific achievement. The first example of this was provided by the measurements made in the next year by a British team in the Kurchatov Institute, the results of which made a great contribution towards overcoming the remaining doubts about tokamaks.

    Artsimovich became a 'missionary physicist', traveling all over Europe and North America to spread the gospel, but he continued to warn us not to rely exclusively on the tokamak and to go ahead on a wide front.

    Around 1970 new tokamaks were built in almost all the fusion laboratories throughout the world: in the USSR, the United States of America, Japan and Australia. In Europe we took care to diversify the efforts of the different laboratories in order to produce a generation of tokamaks covering a wide range of physical parameters. The results have been good - I need only mention the important contribution made by the TFR tokamak at Fontenay.

    The existence of a large number of similar experimental machines necessitated a speedy exchange of information, and we saw a multiplication of conferences and meetings on a world-wide scale. Positive results soon accumulated, and progress was rapid. It is worth while to note that this first big success in the field of fusion was reached in a confinement scheme which, in conformity with Artsimovich's predictions, has so far been working at low beta.

    It is difficult to say at this stage whether the tokamak is the best solution for a thermonuclear reactor, even if there are no reasons to say the contrary. What is undeniable is that the plasma parameters, density, temperature, purity and duration, produced simultaneously in the tokamak, have provoked (and permitted) enormous progress in the study of stability and transport, the improvement of diagnostics and the development of powerful methods of plasma heating.

    It soon became evident that substantial progress could only be made with the construction of very large tokamaks. The four big programmes already existing at that time (Euratom, Japan, the USA and the USSR) examined the same problem separately and reached similar, even if not identical, conclusions. Thus, in the Euratom programme the JET project was started; in Japan, JT 60; in the USA, TFTR; and in the USSR, initially T 20, later replaced by T 15. These four projects are now under construction independently although the relevant information is circulating freely and abundantly. This atmosphere made possible a number of bilateral agreements, for instance between the USSR and the USA and, last but not least, between the USA and Japan.

    At the same time, the two large Agencies, the IAEA and the International Energy Agency (IEA), intensified their commitment to fusion. The former promoted a number of conferences, symposia and international study groups and has kept governments informed on progress and prospects in fusion. The latter has brought about, by the conclusion of agreements mainly between Euratom. the USA and Japan. the realization of several common projects in the field of fusion technology.

    In the meantime a new problem has arisen. It is hoped that the devices of the JET generation will enter the domain of plasma parameters required for a fusion reactor and will give us the possibility of studying the remaining major physical problem: the behaviour of burning plasmas. But these machines will not have any of the other elements necessary for a reactor (recovery and utilization of the energy produced, fuel breeding, etc.). A new generation of devices is therefore necessary. The construction cost of a JET-like machine is of the order of half a billion US dollars, and requires a great scientific and technological commitment. Each machine of the subsequent generation -- which, almost inevitably, will be a tokamak again -- will cost at least two or three times as much and will require much greater technological developments. It is questionable whether each of the four big programmes can proceed individually along the tokamak line and at the same time continue its activities, even on a smaller scale, along a wider front.

    One of the first to set the problem in a very explicit form was David Rose of MIT. Towards the end of 1977, when the construction of TFTR had just begun and that of JET had just been approved, he invited representatives of the four big programmes to discuss the future of fusion and in particular the role of international cooperation. At that meeting, the building of the next device collectively, under the aegis of either the IAEA or the IEA, was considered a distinct possibility, as was the need to proceed to some sharing of tasks among the programmes on the remaining lines. A few months later, during the IFRC meeting in May 1978, Academician Velikhov, leader of the USSR programme, proposed starting the study of the next large tokamak (now called INTOR) as a joint venture under the auspices of the IAEA.

    We now come to the Innsbruck Conference in 1978, where progress in the tokamak line was confirmed from several sides and the remarkable results on plasma heating in PLT at Princeton were reported. During that conference, as anticipated by Kintner in his Artsimovich Memorial Lecture, the IFRC proposed proceeding with INTOR in four phases: data-base assessment, definition, detailed design, and construction. Each phase would require a separate decision by the four parties involved. These proposals were supported and acted upon by the Director General of the IAEA.

    A group of four or five experts per programme was then set up and, starting from February 1979, they met periodically in Vienna for a few weeks at a time and at the end of 1979 produced a conclusive report on the data-base assessment phase. It was subsequently agreed to proceed to the definition phase, which will last for yet another year from now. I need not go into details of the work of this group, the results of which were reported yesterday. In my opinion yesterday's meeting was the best homage that we could offer to the memory of Artsimovich, for two reasons: first because it concerns the field to which he had contributed so much, and second because it is the product of international collaboration which twenty years ago in Geneva he had recommended as an essential tool for progress in fusion.

    A very important aspect of the Vienna workshops was that each delegation regularly brought proposals and ideas which, in the intervals between the meetings, had matured within each of the four programmes and which were subsequently discussed, evaluated and selected during the joint meetings. Thus a climate has been maintained for the generation of independent and original ideas and a forum provided for their critical assessment. This work has certainly been very encouraging, and whatever the follow-up may be, it will represent an important contribution to the progress of fusion.

    Concerning the other lines of approach, progress has been realized in both research and collaboration. The basic concepts are still essentially the same as they were in Geneva twenty years ago, but the situation has changed in two ways. First, the target for the alternative lines is more clearly defined. To be of value, their performance must be at least as good as the tokamak's, which implies, for each line, the building of large machines. This suggests a sharing of tasks between the different programmes. Secondly, the challenge to the tokamak can be based on progress made in the meantime: for example in the field of mirrors (Moscow and Livermore), stellarators (Garching) and reversed-field pinches (Padua, Culham and Los Alamos). On these last two lines we are actively working towards some cooperation between the USA and Euratom which still has to be finalized.

    Until now, the level of international cooperation has proved adequate. It is imperative that this fruitful cooperation should be further reinforced; failure to do so now would make it more difficult in the future. So we must now ask the public authorities not only for a strong increase in our research funds but also for support and initiative in the field of international relations, hoping that success in the latter will enable us to reduce the former.

    What can we offer in exchange? Even if, in the last twenty years, the possible advantages of fusion (cleanliness, safety and economy) have undergone some reassessment, it remains one of the few potential solutions of all the problems in the field of energy. Since, in the meantime, these problems have become dramatic, the balance remains largely positive. How long will it take? Going back to Budker, this will depend jointly on our own abilities and the commitment of the public authorities.

    May I conclude by again using Artsimovich's allegory? As regards plasma physics, at least in the tokamak line, our stay in purgatory seems to be reaching its end. But the thermonuclear reactor has both physical and technological requirements. As technologies have just started their journey, a prolonged stay in purgatory is to be expected for them. However, we know that the sojourn in purgatory can be curtailed not only by penitence on the part of the sinner but also by payment for indulgences.

    So, with continued and dedicated efforts by scientists and engineers, and with support both in financial terms and political commitment from the authorities, the prospects of being able to proceed to a demonstration reactor by the end of the century appear very good indeed.

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