A fully kinetic assessment of the stability properties of toroidal drift modes has been obtained for nonaxisymmetric (stellarator) geometry, in the electrostatic limit. This calculation is a comprehensive solution of the linearized gyrokinetic equation, using the lowest-order \ballooning representation" for high toroidal mode number instabilities, with a model collision operator. Results for to...

The first sustainment of toroidal plasma current of 50 kA at up to 3 times the injected currents, added in quadrature, using steady inductive helicity injection is described. Separatrix currents-currents not linking the helicity injectors-are sustained up to 40 kA. Decreases in the n=1 toroidal mode of the poloidal magnetic field at higher current amplifications indicate more quiescent, direct ...

Measured damping rates of stable Toroidal Alfvén Eigenmodes (TAEs) have been compared with damping rates calculated with the NOVA-K code for a number of experimental conditions on Alcator C-Mod in an attempt to validate the NOVA-K damping model. Very low amplitude ( / B B θ θ ~ 10 -7 at the wall) stable TAEs are excited in Ohmic plasmas with a pair of active MHD antennas inside C-Mod. By sweepi...

One of the goals of the National Spherical Torus Experiment (NSTX) is to investigate the physics of global mode stabilization in a low aspect ratio device. NSTX has a major radius R0 = 0.86 m, a midplane half-width of 0.7 m, and an on-axis vacuum toroidal field B0 0.6 T and has reached a plasma current Ip = 1.5 MA. Experiments have established the wall-stabilized MHD operating space of the mach...

Toroidal rotation is well known to play significant roles in the edge transport and L–H transition dynamics of tokamaks. Our recent calculation finds that a sufficiently strong localized toroidal can directly bring out formation pressure pedestal with reversed magnetic shear reminiscent an H-mode plasma, purely through effects on tokamak MHD equilibrium itself. In particular, enhanced enables s...

Magnetic islands have been implemented in the gyrokinetic toroidal code to study the effects of the islands on microturbulence. The pressure profile flattening is verified in the simulation with the islands. Simulations of ion temperature gradient instability find that different toroidal modes are linearly coupled together and that toroidal spectra become broader when the island width increases...

Effect of a toroidal rotation on the type-I edge localized mode in JT-60U is investigated numerically. As the result of the numerical analysis, it is confirmed that the plasma rotating experimentally in the co-direction to the plasma current is approximately on the stability boundary of the MHD mode even when the rotation is neglected. However, the plasma rotating in the counter-direction is fa...

We report guided-light opto-mechanical sensing of the mechanical vibrations of a toroidal-lipped SiO2 GOBLiT. An optical quality factor of 1.7x10 allowed us to measure mechanical vibrations of the GOBLiT with mechanical quality factor 206 in air for the n=2 degenerate wineglass mode. Light was coupled into the resonator via a tapered optical fiber and used to sense mechanical motion of the GOBL...

We theoretically investigate the use of red-detuned Laguerre-Gaussian (LG) laser beams of varying azimuthal mode index for producing toroidal optical dipole traps in two-dimensional atomic Bose-Einstein condensates. Higherorder LG beams provide deeper potential wells and tighter confinement for a fixed toroid radius and laser power. Numerical simulations of the loading of the toroidal trap from...