1ST RESULTS FROM ALCATOR-C-MOD

Early operation of the Alcator-C-MOD tokamak [I.H. Hutchinson, Proceed ings of IEEE 13th Symposium on Fusion Engineering, Knoxville, TN, edit ed by M. Lubell, M. Nestor, and S. Vaughan (Institute of Electrical an d Electronic Engineers, New York, 1990), Vol. 1, p. 13] is surveyed. R eliable operation, with plasma current up to 1 MA, has been obtained, despite the massive conducting superstructure and the associated error fields. However, vertical disruptions are not slowed by the long vess el time constant. With pellet fueling, peak densities up to 9 X 10(20) m-3 have been attained and ''snakes'' are often seen. Initial charact erization of divertor and scrape-off layer is presented and indicates approximately Bohm diffusion. The edge plasma shows a wealth of marfe- like phenomena, including a transition to detachment from the divertor plates with accompanying radiative divertor regions. Energy confineme nt generally appears to exceed the expectations of neo-Alcator scaling . A transition to Ohmic H mode has been observed. Ion cyclotron heatin g experiments have demonstrated good power coupling, in agreement with theory.