Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 12 of 12 for “"Tearing mode"”.
-
Tearing-mode transport model in the reversed field pinch concept
In this thesis, a self-consistent model for analyzing the transport performance of a Reversed Field Pinch (RFP)-type of thermonuclear fusion reactor has been developed. The study has been focused on determining equilibrium configurations which describe a plasma evolution dominated by particular …
-
Stabilization of the tearing mode by turbulent diffusion and runaway electrons
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1986.
-
Magnetic reconnection in high-temperature plasmas : excitation of the drift-tearing mode and the transport of electron thermal energy
The problem of excitation of the drift-tearing mode (Coppi, 1964) in high-temperature plasmas is considered. Existing theories predict that under the conditions typical of modern toroidal experiments on nuclear fusion, the mode is linearly stable in both collisionless (Coppi et al., 1979), and in a …
-
Inertial tearing modes in magnetically-confined plasmas
… behavior of the plasma instability known as the tearing mode in parameter regimes relevant to magnetically-confined fusion plasmas. This included a derivation of the relevant equations and a method of solving them using Fourier analysis. This method allowed the derivation of several analytic …
-
Analysis of magnetohydrodynamic (MHD) activity using electron cyclotron emission (ECE) diagnostics on Alcator C-Mod tokamak
… current ramp-up discharges (resistive 'multiple' tearing mode and ideal interchange mode) and ii) a new approach to diagnose edge localized modes (ELMs) using ECE diagnostics was explored. Both MHD modes were accompanied by hollow pressure and current profiles. The associated q-profiles were also …
-
Investigation of model micro-scale reconnecting plasma modes
… and analytically investigate the linear complex mode frequencies of model micro-reconnecting plasma modes which have transverse wavelengths of the order of the electron skin depth c/lwpe. This model mode, which can have finite wavelength parallel to the magnetic field, is found in the limit of a …
-
Coronal magnetic energy release by current sheet reconnection
… Other aspects of 2-D merging covered include the tearing mode instability, osculation and the effects of finite compressibility. We employ a 3-D time-dependent code, in Chapter 4, to check that the analytically predicted spine and fan forms develop from general initial conditions. Scalings with …
-
A combined phase contrast imaging and heterodyne interferometer system for multiscale fluctuation measurements on DIII-D
… bound of the electron temperature gradient (ETG) mode has been designed, installed, and operated at the DIII-D tokamak. The combined diagnostic was constructed by adding a heterodyne interferometer to the pre-existing phase contrast imaging (PCI) system, both of which measure line-integrated …
-
Radiation asymmetry and MHD activity in rapid shutdowns on Alcator C-Mod
… asymmetry is controlled by a low-n brightness mode in the TQ phase of rapid shutdowns. is mode sometimes rotates, and the rate of rotation sets the integrated radiation asymmetry in the TQ. It is proposed that this brightness feature is caused by the transport of energy from the hot plasma core …
-
Data-driven study of major disruption prediction and plasma instabilities across multiple tokamaks
… and disruptions using first-principle models has been demonstrated to be extremely difficult, due to the complexity of the problem and the high non-linearity of the system. To date, disruption and plasma instabilities prediction has been studied through two main approaches: data-driven …
-
Resistive instabilities in magnetically confined fusion plasmas with velocity shear and rotation
… effects of velocity shear and rotation on linear tearing layer stability are studied for tokamak equilibria. The separation-of-time-scales formalism needed for a proper formulation of ideal and resistive stability calculations is presented. Using this formalism, a dispersion relation is first …
-
The effects of flow on resistive instabilities in magnetohydrodynamics
… to a state of lower energy.<br/><br/>The model studied in this thesis is the plane magnetic current layer in which a gravitational acceleration acting normally to the magnetic surfaces is introduced to simulate the effects of magnetic field line curvature of more realistic geometries. The …