The Macrostability Topical Group will address the five questions of the workshop as they relate to issues of ideal and non-ideal MHD stability. (Issues of the interaction of MHD modes with alpha particles will be covered mainly in the Energetic Alpha-Particle Physics group.) The following questions may serve as a partial guide to the discussions:
* How confidently can we predict stability limits and growth rates in a burning plasma?
* Does possible scaling of MHD stability properties with rho-star (normalized ion gyroradius) or S (magnetic Reynolds number) require a burning plasma-class device to investigate?
* How might neoclassical tearing mode physics (threshold beta, seed island formation) vary in a burning plasma?
* What are the consequences of MHD instabilities (sawteeth, ELMs, tearing modes, etc.) in a burning plasma?
* What aspects of disruption physics (e.g., runaway electron generation) differ in a large, low collisionality plasma?
* Are proposed methods of active MHD control compatible with a burning plasma?
* What is the effect on MHD stability of core pressure profiles determined by alpha heating? of bootstrap current profiles consistent with alpha heating?
* Can the rotation profile of a self-heated plasma be predicted? How will it affect MHD stability?
* Which issues of MHD stability in a burning plasma are generic, and which are specific to particular magnetic confinement configurations?
* What are the opportunities and limitations for addressing any of these questions in existing devices?