TFTR Initial operations

TSTR (Tokamak Fusion Test Reactor) has operated since December 1982 with ohmically heated plasmas. Routine operation with feedback control of plasma current, position and density has been obtained for plasmas with I p ≃800 kA, a = 68 cm, R = 250 cm, and B t =27 kG. A maximum plasma current of 1 MA was achieved with q≃2.5. Energy confinement times of ~150 msec were measured for hydrogen and deuterium plasmas with e = 2 x 10 13 cm -3 , T e (0) 2≃1.5 keV, T i (0) = 1.5 keV and Z eff ≃1 3. The preliminary results suqgest a size-cubed scaling from PLT, and are consistent with Alcator C scaling where T ∼ nR 2 a. Initial measurements of plasma disruption characteristics indicate current decay rates of ∼ 800 kA in 8 ms which is within the TFTR design requirement of 3 MA in 3 ms.