Pulsed RF schemes for tearing mode stabilization

Tearing Mode Stabilization in Tokamaks with Lower Hybrid Waves

The possibility of using lower hybrid (LH) waves as a source of localized current for the control of MHD instabilities is investigated. A toroidal ray tracing code is used to define the requirements on the launched wave spectrum, in order to drive currents mostly localized inside the magnetic islands. Issues such as the radial diffusion of the non-inductive current, the impact of the radial pro...

Time-dependent Simulations of Neoclassical Tearing Mode Stabilization in TCV

Complete stabilization of neoclassical tearing modes with lower hybrid current drive on COMPASS-D. RF teams.

Lower hybrid current drive (LHCD) with modest powers ( approximately 10% of the total power input) has been used for the first time to completely stabilize performance limiting neoclassical tearing modes in many COMPASS-D tokamak discharges. The stabilizing effect in these experiments is consistent with a reduction in the free energy available in the current profile to drive tearing modes (i.e....

)ecember 1982 STABILIZATION OF THE TEARING MODE IN LOW DENSITY TOKAMAK PLASMAS BY TURBULENT ELECTRON DIFFUSION*

The effect of turbulent electron diffusion from stochastic electron orbits on the stability of low beta fluctuations is considered. A set of coupled self-adjoint equations is derived for the fluctuation potentials and A,,. For the tearing mode, it is shown that stability is obtained for sufficiently large values of the diffusion coefficient, Provided D, 1/n, this implies that a density threshol...

Fast and Slow Nonlinear Tearing Mode Reconnection

1. Introduction. The standard theory of the tearing-mode evolution identifies three stages. The first is the linear stage described by the Furth–Killeen–Rosenbluth (FKR) theory [1]. During this stage, the island width W grows exponentially in time until it reaches the width of the resistive dissipation layer, ℓ η ∝ η 2/5 ∆ ′1/5 , where η is the resistivity and ∆ ′ is the instability parameter [...