The Vacuum System
Creating and maintaining the ultra-high vacuum a plasma needs.
- Role
- Ultra-high vacuum
- Method
- Cryopumping
A fusion plasma must sit inside an ultra-high vacuum so that stray gas does not cool or contaminate it. Cryopumps and roughing systems pump the vessel to a very low base pressure before and during operation.
The vacuum system is standard high-vacuum engineering scaled up, and is not among the design's binding gates.
The plasma must sit in ultra-high vacuum so that stray gas cannot cool or contaminate it, and reaching a very low base pressure is a cold-commissioning milestone. Cryopumps provide the high pumping speeds needed to hold density and exhaust helium ash, and the same system handles the tritium-bearing exhaust on the breeder.
Common questions
So stray gas cannot cool or contaminate the plasma. Reaching a very low base pressure is a cold-commissioning milestone, and cryopumps provide the high pumping speeds to hold density and exhaust ash.
On the breeder, yes — it manages the tritium-bearing exhaust, so vacuum and tritium handling are linked systems there.