Plug Field Ramp-Up
The high-field plug coils are ramped to the 26.49 T class in a controlled sequence with quench protection continuously live.
The plug coils create the highest field in the machine — 26.49 T at the plug, with the throat at 17 T. Ramping them up is a controlled, monitored operation because these coils carry the most current and store the most energy. Quench protection is live throughout, and the ramp respects thermal and mechanical limits.
Controlled ramp
Field is raised in steps, with time at each level to confirm coil temperature, mechanical response, and protection status before proceeding. The ramp rate is bounded so that mechanical stress and any localized heating stay within limits. The central-cell and throat coils are coordinated so the mirror field profile builds coherently.
Protection during ramp
- Quench detection monitors every coil continuously
- Structural instrumentation tracks mechanical load
- The fast-discharge path is armed and tested before ramp
- Cryoplant absorbs the ramp's added heat load
Reaching the operating field
At full field the mirror profile is established: strong plugs at each end, a lower on-axis field (8 T class) in the central cell, and the throat transition to the expander. Plasma initiation and plug formation follow. The 26.49 T plug and 17 T throat are frozen design values; the ramp is engineered and simulated at design stage and demonstrated on the first test burner.