Tokamak research

Progress in tokamak research is reviewed for the period 1971–74. The theories of MHD-stability, classical transport and anomalous transport have been refined. The tokamak device population has increased by about an order of magnitude. Non-Ohmic heating methods have been developed successfully. The severity of the problem of plasma impurity has been recognized, and technological countermeasures are being developed. The experimental results on energy confinement are not yet well understood theoretically and cannot be fitted by any simple empirical transport coefficient; the general empirical trend, however, is favourable to the achievement of reactor plasma conditions in large future tokamak devices.