UKAEA Journals

Showing 1 - 6 of 6 Journals Results

The interaction of Alfvén Eigenmodes (AEs) and energetic particles will determine the success of future tokamaks. In JET, eight in-vessel antennas were installed to actively probe stable AEs with frequencies ranging 25 – 250 kHz and toroidal mode numbers |n| < 20. During the 2019-2020 deuterium  campaign, almost 7500 resonances and …


The most recent JET campaign has focused on characterizing operation with the "ITER-like" wall. One of the questions that needed to be answered is whether the auxiliary heating methods do not lead to unacceptably high levels of impurity influx, preventing fusion-relevant operation. In view of its high single pass absorption, hydrogen minority funda…


Application of lower hybrid (LH) current drive in tokamak plasmas can induce both co- and countercurrent directed changes in toroidal rotation, depending on the core q profile. For discharges with q0 < 1, rotation increments in the countercurrent direction are observed. If the LH-driven current is sufficient to suppress sawteeth and increase q0 abo…


Using theoretical arguments, a simple scaling law for the size of the intrinsic rotation observed in tokamaks in the absence of a momentum injection is found: The velocity generated in the core of a tokamak must be proportional to the ion temperature difference in the core divided by the plasma current, independent of the size of the device. The co…


Recent advances in modeling the effects of anisotropic energetic ion distributions have enabled the development of a complete coherent physics explanation of sawtooth stabilization in both conventional and spherical tokamaks. As an example, a complete model has been developed to explain the asymmetric stabilization of sawteeth with respect to neutr…


During a recent reversed toroidal field (B T) campaign at the Joint European Torus (JET), experiments were performed to investigate the effect on sawteeth of neutral beam injection (NBI)-driven toroidal plasma rotation counter to the direction of the toroidal plasma current and B T . A power scan at constant density has permitted analytical continu…