Global and local confinement analysis of JET's VH-mode pulses

Plasmas with the energy confinement time enhanced by a factor 1.4 to 2.1 over the ITER93H-P H-mode scaling expression have been obtained in 3 different H-mode regimes (excluding pellet injection) in JET. The phase of enhanced confinement has strong similarities with the VH-mode observed in DIII-D in all 3 cases. The JET data clearly show VH-mode confinement increasing with plasma current and degrading with loss power.