Energy confinement in JT-60 lower hybrid current driven plasmas

The energy confinement in high power lower hybrid current driven (LHCD) plasmas has been studied in the JT-60 tokamak. At a plasma current of 1 MA, the diamagnetically estimated energy confinement time in LHCD plasmas has almost the same value as the confinement time in ohmically heated plasmas at e ∼ 1.0 × 10 19 m −3 . The confinement time of high power LHCD plasmas (P LH ≤ 4.5 MW) is longer than that of neutral beam heated plasmas at the same power level. The energy confinement time depends on the LHCD power and on the electron density, but is independent of the plasma current, with α + β ∼ −0.3.