Glossary of Fusion & Plasma Terms
The Beta Limit
The maximum plasma pressure a magnetic configuration can stably hold.
- Breeder beta-N
- 1.532
Beta limits cap how much plasma pressure a given field can confine before instabilities grow. Operating below them bounds the achievable power density. HYPERION runs at βN = 1.532, within the no-wall limits observed on spherical tokamaks.
Its low aspect ratio is what lets it hold high beta while staying within these limits.
Beta limits are the stability ceilings on plasma pressure, and running below them with margin is what separates a robust design from a fragile one. HYPERION's βN = 1.532 sits below the no-wall limit, so it does not depend on a conducting wall or active feedback to stay stable — a conservative choice reflected across the design.