Tokamak fusion reactor

Tokamak Fontenay-aux-Roses Tokamak Fusion Test Reactor... 

Ring-shaped nuclear fusion research reactor Tokamak 15 at the Kurchatov Institute, Moscow, Russia. (Photo Researohers Ino.)... 

The Tokamak Fusion Test Reactor at the Princeton Plasma Physics Laboratoi y produces fusion. 

Fusion has already been achieved in several devices, but not beyond the break-even point, where the amount of energy produced is the same as the amount consumed. Much basic research is still required and is the focus of a number of international collaborative efforts. As discussed in Chapter 4, foremost among these efforts is the International Thermonuclear Experimental Reactor (ITER), which will be a scale-up of the Princeton Tokamak Fusion Test Reactor shown in Figure 19.17. 

The Tokamak Fusion Test Reactor was the first fusion facility with extensive experience with tritium fuelling and removal. During the 3.5 years of D-T operation, 3.1 g T was supplied to the plasma by neutral beam injection and... 

C.H. Skinner, W. Blanchard, J.N. Brooks et al., Tritium experience in the Tokamak Fusion Test Reactor, Proc. 20th Symp. on Fusion Technology, Marseille, Sept. 1-11, 1998, Vol. 1, p. 153... 

Despite great strides, the problems arising from plasma-material interactions (PMIs), together with the selection of plasma facing materials, still represent major challenges for the reliable and safe operation of a D-T next-step tokamak [1]. They also remain potential obstacles for the successful development of future fusion power reactors. These issues came into sharp focus during D-T operation of the Tokamak Fusion Test Reactor (TFTR) and the Joint European Torus (JET) and, in particular, in the process of designing ITER. 

The characteristic circular-shape of the tokamak reactor is clearly seen here. The reactor uses strong magnetic fields to contain the intensely hot fusion reaction and keep it from direct contact with the interior reactor walls. 

Why does nuclear fusion require so much heat How is heat contained within a tokamak reactor (25.4)... 

This first experiment with tritium was followed on 9 December 1993 by an experiment with up to 50 per cent tritium at the Plasma Physics Laboratory of Princeton (USA) which produced power of 5-28 MW with the Tokamak Fusion Test Reactor (TFTR) machine. 

If a linear relation between the volumetric power density and neutron wall load is assumed, extrapolation of the data from the two fusion reactor designs yields the curves shown in Fig. 10, where the dependence of the blanket volume on the power density is ignored (optimistic extrapolation ). Compacting the construction beyond a certain limit is achieved at the expense of complexity and availability. The upper compacting limit is characterized by the so-called most compact tokamak reactor (A = 3 r = b = 1.75 m), whose power refers to the sum of the net volumes of the plasma vessel and the outer system (b), which comprise the blanket,... 

Baker C. C. et ah, STARFIRE - Commercial Tokamak Reactor, in Proc. of 8 Symp, on Engineering Problems of Fusion Research, San Francisco 1979... 

Comparison of a Tokamak reactor with a PWR can be founded on considerations of such a basic nature that it becomes almost automatic to ask how far the various unconventional approaches to fusion are exempt from the Tokamak s drawbacks. 

An unconventional approach to fusion deserves to be considered as an alternative to the Tokamak reactor if it appears to be exempt from some of the constraints which prevent the Tokamak from behaving more satisfactorily. At the cost of writing an unconventional foreword to this book, I shall try to review the limitations inherent in a Tokamak, and in doing so, I find it rather convenient to borrow a bit of the language of fission people viz. I shall use the so-called conductivity integral ... 

Ve is larger than the plasma volume by a factor of 4Ay i.e. about 16. Ve and the type of technology needed for the construction of the items contained in it, are the basic data for the evaluation of the economic and operational aspects of the Tokamak reactor. Of course it must also be considered that the cost of the reactor block is a fraction of the total plant cost. Unfortunately it seems (see lectures by K. H. Schmitter and N. A. Krall) that, as distinct from the fission case, for most of the fusion alternatives to the Tokamak and almost certainly also for the Tokamak itself, the cost of the nuclear island is dominant, i.e. it is larger than the cost of the balance of plant. However, in comparison with a fission reactor, one must consider that the major cost of the fusion reactor is compensated by the much smaller cost of fuel provision and by the undeniable social advantages fusion has with respect to fission. K. H. Schmitter in his lecture demonstrated that it is impossible in a Tokamak to raise pc to values typical of a PWR maintaining the field and geometry pattern pointed out previously in these pages. 

Figure 21.21 A drawing of the tokamak fusion test reactor. A tokamak is essentially a magnetic "bottle" for confining and heating nuclei in an effort to cause them to fuse. 

The plasma in a fusion reactor must not touch the walls of its vacuum vessel, which would he vaporized. In the Tokamak fusion test reactor, the plasma is contained within a magnetic field shaped like a doughnut. The magnetic field is generated hy D-shaped coils around the vacuum vessel. 

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