Abstract
An investigation is presented of how the stability of collisionless electromagnetic interchange modes depends on {epsilon}{sub n} (the ratio of the magnetic drift frequency to the diamagnetic drift frequency), the ion temperature gradient and the electron temperature gradient. A linear two fluid model in toroidal geometry is used. The eigenvalue problem is solved analytically and then the complex frequency is solved numerically from the dispersion relation. Comparison is made with Merciers criterion, in the magnetohydrodynamic limit. The most important observed effects are : 1. When {epsilon}{sub n} increases Merciers criterion becomes increasingly incorrect. The toroidal system becomes more stable than Merciers criterion predicts. {epsilon}{sub n} is large in regions where we have flat density profiles, L{sub n} >> L{sub B} (the characteristic scale length of density and magnetic field inhomogeneities). 2. Finite {eta}{sub i} (L{sub n} / L{sub Ti}) may cause instability below the critical pressure gradient in the Mercier criterion.
Citation Formats
Wernefalk, H, and Weiland, J.
Stability analysis of electromagnetic interchange modes in toroidal geometry.
Sweden: N. p.,
1992.
Web.
Wernefalk, H, & Weiland, J.
Stability analysis of electromagnetic interchange modes in toroidal geometry.
Sweden.
Wernefalk, H, and Weiland, J.
1992.
"Stability analysis of electromagnetic interchange modes in toroidal geometry."
Sweden.
@misc{etde_10127535,
title = {Stability analysis of electromagnetic interchange modes in toroidal geometry}
author = {Wernefalk, H, and Weiland, J}
abstractNote = {An investigation is presented of how the stability of collisionless electromagnetic interchange modes depends on {epsilon}{sub n} (the ratio of the magnetic drift frequency to the diamagnetic drift frequency), the ion temperature gradient and the electron temperature gradient. A linear two fluid model in toroidal geometry is used. The eigenvalue problem is solved analytically and then the complex frequency is solved numerically from the dispersion relation. Comparison is made with Merciers criterion, in the magnetohydrodynamic limit. The most important observed effects are : 1. When {epsilon}{sub n} increases Merciers criterion becomes increasingly incorrect. The toroidal system becomes more stable than Merciers criterion predicts. {epsilon}{sub n} is large in regions where we have flat density profiles, L{sub n} >> L{sub B} (the characteristic scale length of density and magnetic field inhomogeneities). 2. Finite {eta}{sub i} (L{sub n} / L{sub Ti}) may cause instability below the critical pressure gradient in the Mercier criterion.}
place = {Sweden}
year = {1992}
month = {Dec}
}
title = {Stability analysis of electromagnetic interchange modes in toroidal geometry}
author = {Wernefalk, H, and Weiland, J}
abstractNote = {An investigation is presented of how the stability of collisionless electromagnetic interchange modes depends on {epsilon}{sub n} (the ratio of the magnetic drift frequency to the diamagnetic drift frequency), the ion temperature gradient and the electron temperature gradient. A linear two fluid model in toroidal geometry is used. The eigenvalue problem is solved analytically and then the complex frequency is solved numerically from the dispersion relation. Comparison is made with Merciers criterion, in the magnetohydrodynamic limit. The most important observed effects are : 1. When {epsilon}{sub n} increases Merciers criterion becomes increasingly incorrect. The toroidal system becomes more stable than Merciers criterion predicts. {epsilon}{sub n} is large in regions where we have flat density profiles, L{sub n} >> L{sub B} (the characteristic scale length of density and magnetic field inhomogeneities). 2. Finite {eta}{sub i} (L{sub n} / L{sub Ti}) may cause instability below the critical pressure gradient in the Mercier criterion.}
place = {Sweden}
year = {1992}
month = {Dec}
}