Alcator C operations commenced with discharge cleaning and tokamak operation using hydrogen filling gas. Prior to and during these experiments no deuterium gas was allowed into the device. The earliest operation resulted in dosimeter readings of a few Roentgen per shot in the vicinity of the limiter and a localized source of neutron emission of 9 up to 10 neutrons/shot. A strong correlation of ...

Neoclassical Computation of Temperature Anisotropy in the National Spherical Torus Experiment David Perkins Department of Physics and Astronomy Bachelor of Science The National Spherical Torus Experiment (NSTX), underway at Princeton Plasma Physics Laboratory (PPPL), investigates the plasma dynamics in a spherical tokamak to understand the device’s potential as a fusion power generator. Tempera...

In previous Compact Toroid (CT) injection experiments on several tokamaks, although CT fuelling had been successfully demonstrated, the CT fuelling process has been not clear yet. We have thus conducted CT injection into simple toroidal or vertical vacuum magnetic fields to investigate quantitatively dynamics of CT plasmoid in the penetration process on a spherical tokamak (ST) device. Understa...

This paper reviews various global instabilities destabilized by tangential neutral beam injection (NBI) in the Large Helical Device (LHD) plasmas. These global modes are toroidal Alfvén eigenmodes (TAEs), which are also observed in tokamak plasmas, and helicity-induced Alfvén eigenmodes (HAEs) which are observed only in three-dimensional plasmas such as LHD plasmas. Moreover, reversed magnetic ...

Full cross section calculations of ion-temperature-gradient-driven turbulence with Landau closure are being carried out as part of the Numerical Tokamak Turbulence Project, one of the U. S. Department of Energy’s Phase II Grand Challenges. To include the full cross section of a magnetic fusion device like the tokamak requires more memory and CPU time than is available on the National Energy Res...

The energy confinement time of tokamak plasmas scales positively with plasma size and so it is generally expected that the fusion triple product, nTτE, will also increase with size, and this has been part of the motivation for building devices of increasing size including ITER. Here n, T, and τE are the ion density, ion temperature and energy confinement time respectively. However, tokamak plas...

The first real-time profile control experiments integrating magnetic and kinetic variables were performed on DIII-D in view of regulating and extrapolating advanced tokamak scenarios to steady state devices and burning plasma experiments. The integrated model-based approach that was used is generic and is being developed under the framework of the International Tokamak Physics Activity for Inte...

A series of experiments, examining the confinement properties of ICRF heated H-mode plasmas, has been carried out on the C-Mod tokamak. C-Mod is a compact tokamak which operates at high particle, power, and current densities at toroidal fields up to 8T. Under these conditions the plasma is essentially thermal with very little contribution to the stored energy from energetic ions (typically no m...

The Hamiltonian character of the ray tracing equations describing the propagation of the Lower Hybrid Wave (LHW) in a magnetic confined plasma device (tokamak) is investigated in order to study the evolution of the parallel wave number along the propagation path. The chaotic diffusion of the “time-averaged” parallel wave number at higher values (with respect to that launched by the antenna at t...

A fluid drift-reduced description, which accurately describes phenomena occurring on time scales slower than the characteristic gyro-frequencies and space scales longer than the Larmor radii, has been successfully used in recent years to model the dynamics of tokamak scrape-off layer (SOL) [1]. This region controls the tokamak power and particle exhaust and plays an important role in determinin...