Solitary perturbations (SPs) localized both poloidally and radially are detected within ~100 μs before the partial collapse of the high pressure gradient boundary region (called pedestal) of magnetized toroidal plasma in the KSTAR tokamak device. The SP develops with a low toroidal mode number (typically unity) in the pedestal ingrained with quasi-stable edge-localized mode (QSM) which commonly...

Background The Levitated Dipole Experiment (LDX) at MIT uses a floating donut-shaped supercon-ducting magnet to study the confinement of plasma in a dipole magnetic field. LDX created its first plasma in 2004 and first levitated its su-perconducting magnet in 2007. Compared to the more popular tokamak, first used to create plasma in the 1960s, LDX is a relatively new device. Despite this, there...

The control of tokamak fusion experiments is outlined with particular reference to the evolution of the control from primitive pre-programmed operation, through to feedback control of many parameters, finally developing advanced methods which are destined to optimise the performance of the tokamak plasma. Four examples of enhanced control of tokamak plasmas are given.

Probe measurements in the PISCES linear device indicate the presence of plasma radially far from where it is produced. We show that this is mainly caused by large-scale structures of plasma with high radial velocity. Data from the Tore Supra tokamak show striking similarities in the shape of these intermittent events as well as the fluctuation density probability distribution and frequency spec...

The first measurements of current drive (refluxing) and refuelling by spheromak injection into a tokamak are discussed in detail. The current drive mechanism is attributed to the process of helicity injection, and refuelling is attributed to the rapid incorporation of the dense spheromak plasma into the tokamak. After an abrupt increase (up to go%), the tokamak current decays by a factor of thr...

Alcator C-Mod is a new tokamak under construction at M.I.T. that promises to play an important and flexible role in the international fusion research effort. The physics and engineering features of the tokamak are described, giving an overview of the machine and plasma configurations. On the basis of empirical scaling laws, we predict the plasma confinement performance to be near DT equivalent ...

The need of achieving always better performance in present and future tokamak devices has pushed plasma control to gain more and more importance in tokamak engineering. When high performance and robustness are required, it is essential to adopt a model-based approach to design a control system. In this paper we introduce the basics of plasma current, shape position control in tokamaks. As examp...