Progress in tokamak research at MIT

The major results and accomplishments of the MIT tokamak programme are surveyed. These are considered to be 1) discovery of an Ohmic-heating confinement law in which τ_E ∝ ;aR²; 2) reduction of anomalous ion conduction to the neoclassical value by use of pellet fuelling; 3) formulation of an empirical model for confinement of impurities in ohmically heated tokamaks; 4) seminal experiments on current drive by lower hybrid waves and production of quasi-stationary driven current discharges with n ≈10²⁰ m^–3; and 5) heating of electrons by Landau damping of lower hybrid waves with ΔT_e≈1 keV. The advance of n₀τ_E is also traced from values of about 10^l8 s·m⁻³ which were typical of tokamaks at the beginning of the Alcator programme to values achieved on Alcator C in excess of 6 X 10¹⁹ s·m⁻³, which is required for thermalized energy breakeven at higher temperature.