Adiabatic toroidal compression and free-expansion experiments in TFTR

Major-radius compression of Ohmically heated discharges in TFTR has produced increases in both density and ion temperature nearly in accordance with adiabatic scaling, along with smaller increases in electron temperature. Partial compression experiments have removed the plasma edge from limiter contact so that the free expansion of a tokamak plasma could be studied. During this phase the suspension of the normal processes of recycling and plasma edge cooling permits a transient inversion of the usual relationship between the temperature and density profile widths. Strongly enhanced particle transport and degraded energy confinement have been measured under these conditions. (author)