Incremental energy confinement time during H⁰beam heating in JT-60

Characteristics are presented of the energy confinement time resulting from neutral hydrogen beam heating of JT-60 tokamak plasmas with a plasma current, Ip, of 1-2 MA, a line averaged electron density, e , of 1.5-7 × 10 19 m −3 and an absorbed beam power, P abs , up to 20 MW. The plasma energy content follows an offset linear relation to the absorbed power. The incremental energy confinement time for thermal components, , is almost independent of I p and e at 60 ms, while the incremental energy confinement time for the total plasma energy, , decreases with plasma density. The value of in JT-60 coincides with the prediction of the Shimomura-Odajima scaling of L-mode discharges.