Impurity Transport
How impurities move through the plasma — to be controlled for purity and radiation.
- Goal
- Low core impurities
Impurities entering from the wall or seeded for radiation must not accumulate in the core, where they would dilute fuel and radiate away energy. Impurity transport physics governs where they go, and controlling it keeps Zeff low (HYPERION targets 1.16).
It couples edge radiation (good for the divertor) against core contamination (bad for fusion).
Common questions
Heavy impurities radiate strongly and dilute the fuel, so where they accumulate decides how clean the core stays. HYPERION is designed to a clean Zeff of 1.16.
Through wall conditioning, controlled edge seeding for divertor protection, and good exhaust — balancing enough edge radiation against core contamination as an active control problem.