Plasma instability events such as disruptions, edge-localized modes (ELMs), runaway electrons (REs), and vertical displacement events (VDEs) are continued to be serious events and most limiting factors for successful tokamak reactor concept. The plasma-facing components (PFCs), e.g., wall, divertor, and limited surfaces of a tokamak as well as coolant structure materials are subjected to intens...

The effect of dust grains on the parametric coupling neutral beam driven ion–cyclotron wave instability with a lower hybrid pump is studied. A high amplitude pump, which launched into tokamak for heating purposes in presence ion-cyclotron waves, can excite involving two sidebands. In tokamak, waves result excitation mode and quasi-modes near edge when electron oscillatory velocity greater than ...

High resolution (AX/X z .015) x-ray spectra in the wavelength region 3.7 6.2 A (3.4 + 2.0 keV) have been collected from the Alcator tokamak using a flat crystal Bragg monochromator. Molybdenum L lines and chlorine K lines have been observed and charge state identifications have been made by comparison with calculations. I. Detection System A flat crystal monochromator with a pentaerythritol (PE...

The neoclassical theory of toroidal plasma rotation in the presence of an asymmetric neutral gas source in the edge of tokamak is examined. The poloidal dependence of momentum damping and ion energy loss due to charge-exchange processes are included. It is shown that the toroidal flow velocity increases significantly if the gas is fueled from the inboard side of the tokamak; the radial electric...

Accurate simulations of Neutral Beam Injection (NBI) in tokamak plasmas are vitally important for the analysis of present experiments since NBI is a main heating and current drive tool used in many tokamaks. Different numerical techniques including Monte-Carlo (MC) simulations of beam particles and the solution of the Fokker-Planck (FP) equation for the beam particle distribution function are u...

The fusion-fission hybrid system has the potential attractiveness of good safety performances and plenty of fuel compared to the fission reactor system and also easing the requirement of fusion plasma technology. It is a practical path to the early fusion application for energy production. In this paper, a fusion-driven subcritical reactor for energy multiplier, named FDS-EM, is proposed. It ca...

A tunable correlation electron cyclotron (CECE) system was recently installed on the Alcator C-Mod tokamak to provide local, quantitative measurement of electron temperature fluctuations in the tokamak core. This system represents a significant upgrade from the original CECE system, expanding the measurement capabilities from 4 to 8 total channels, including 2 remotely tunable YIG filters (6-18...

A new model-based plasma current and shape controller has been set up and tested on the JET Tokamak with the existing active circuits and control. The installation has been carried out without causing any interference to the plasma operation and without requiring a long commissioning time. Eventually, the new controller was used on really extremely shaped internal transport barrier experiments ...

The neutral beam injection (NBI) system is designed to provide the ion heating and current drive for the high performance operation and long pulse operation of the Korean Superconducting Tokamak Advanced Research (KSTAR). The KSTAR NBI consists of two beam lines. Each beam line contains three ion sources of which one ion source has been designed to deliver more than 2.5 MW of deuterium neutral ...

Linearly unstable high b tokamak equilibria are shown to be nonlinearly stabilized by an axisymmetric flow containing both toroidal and poloidal components. As fingers of hot plasma produced by pressure driven ballooning instabilities start to convect out towards the bounding wall, an axisymmetric flow is self-consistently generated and opposes the growth of the fingers, maintaining confinement...