High confinement [with H 1 , ITERH- 98 y, 2 ] at b N 2.3 has been found in ASDEX Upgrade discharges with existing m, n 3, 2 neoclassical tearing modes (NTMs). The reason for the high confinement at high b N values is a transition of the NTMs into the so-called frequently interrupted regime. In this regime, the NTM growth is frequently interrupted b…
