Onset and Saturation of a Non-Resonant Internal Mode in NSTX and Implications for AT Modes in ITER
نویسنده
چکیده
Motivated by experimental observations of apparently triggerless tearing modes, we have performed linear and nonlinear MHD analysis showing that a non-resonant mode with toroidal mode number n=1 can develop in the National Spherical Torus eXperiment (NSTX) at moderate normalized βN when the shear is low and the central safety factor q0 is close to but greater than one. This mode, which is related to previously identified “infernal” modes, will saturate and persist, and can develop poloidal mode number m=2 magnetic islands in agreement with experiments. We have also extended this analysis by performing a freeboundary transport simulation of an entire discharge and showing that, with reasonable assumptions, we can predict the time of mode onset.
منابع مشابه
Onset and saturation of a non-resonant internal mode in NSTX and implications for AT modes in ITER
Motivated by experimental observations of apparently triggerless tearing modes, we have performed linear and nonlinear MHD analysis showing that a non-resonant mode with toroidal mode number n = 1 can develop in the National Spherical Torus eXperiment (NSTX) at moderate normalized βN when the shear is low and the central safety factor q0 is close to but greater than one. This mode, which is rel...
متن کاملResistive Wall Mode Stabilization and Plasma Rotation Damping Considerations for Maintaining High Beta Plasma Discharges in NSTX
Maintaining steady fusion power output at high plasma beta is an important goal for future burning plasmas such as in ITER advanced scenario operation and a fusion nuclear science facility. Research on the National Spherical Torus Experiment (NSTX) is investigating stability and control physics to maintain steady high plasma normalized beta with minimal fluctuation. Resistive wall mode (RWM) in...
متن کاملAnalyzing the internal resonances and energy exchange between modes of power system considering Frequency – Energy dependence using Pseudo-Arclength and shooting algorithm
The power system nonlinearity and its profound impact on the individual states of power system is first evaluated and the interaction between their constituent modes during the occurrence of internal mode resonance (IMR) is discussed in this paper. A typical dynamical feature of nonlinear systems is the frequency-energy dependence of their states and their corresponding constituent modes which ...
متن کاملNumerical Calculation of Resonant Frequencies and Modes of a Three-Atom Photonic Molecule and a Photonic Crystal in an External Cavity
In the present paper, resonant frequencies and modes of a three-atom photonic molecule and a photonic crystal placed within a cavity are numerically calculated. First, governing formulation in transverse electric field mode (TE) is obtained using Maxwell equations. Then, an algorithm based on a finite difference scheme and matrix algebra is presented. The algorithm is then implemented in a comp...
متن کاملDetermination of Resonance Frequency of Dominant and Higher Order Modes in Thin and Thick Circular Microstrip Patch Antennas with Superstrate by MWM (RESEARCH NOTE)
An accurate model named as the Modified Wolff Model (MWM) is presented as an efficient CAD tool for determination of resonant frequency of the dominant and higher order modes under the multi-layer condition in thin and thick circular microstrip patch antennas. The effects of dielectric cover on the resonant frequency obtained from MWM have been compared against the result of theoretical method ...
متن کامل