Simons Hour Talk

Linearized Ideal Magnetohydrodynamic Stability in Stellarators
May 25, 2023, 10:00 am11:00 am



Event Description

Abstract:  In the past, aspects of linearized ideal MHD stability,  e.g. the vacuum field magnetic well, reduced parallel  current density, or Mercier's criterion, were targeted for in the optimization of stellarator experiments such as W7-X and HSX. In this tutorial, the stability  of plasma equilibria is discussed based on the energy  principle of ideal MHD in the form of global mode analyses  and local stability criteria. The field-line ballooning  equation and Mercier's criterion are derived. Example  applications typical for various classes of equilibria  (tokamak, stellarator, weak or medium magnetic shear)  are used to point out relationships between the violation  of the local stability criteria and the spatial structure of global modes aiming at a categorization of ideal MHD  stability limits. In the light of experimental results  of the W7-AS stellarator and of the LHD torsatron, experiments are planned in W7-X to clarify the question of  how important ideal MHD is in stellarator optimization.

Talk time in other timezones:
AEST 12:00 AM Fri 26 May,
JST  11:00 PM Thu 25 May,
CEST  4:00 PM Thu 25 May,
BST   3:00 PM Thu 25 May,
UTC  14:00    Thu 25 May,
EDT  10:00 AM Thu 25 May,
CDT   9:00 AM Thu 25 May,
MDT   8:00 AM Thu 25 May,
MST   7:00 AM Thu 25 May
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