Normal Shutdown Sequence

A planned shutdown reverses startup in a controlled order, ending in a cold or warm safe state as maintenance requires.

A normal shutdown is a planned, controlled transition from operation to a safe state. It reverses the startup sequence: the burn is ended, plasma is safely terminated, magnets are de-energized in a controlled ramp, and the plant is placed in the state required for standby or maintenance.

Controlled termination

The burn is ramped down by reducing fueling and heating, then the plasma is terminated in a controlled way that avoids stressing components. Because the machine is steady-state rather than pulsed, an ordinary shutdown is gentle compared with the fast discharge reserved for faults.

Magnet de-energization

• Coils are ramped down within thermal and mechanical limits
• Stored magnetic energy is managed as it is removed
• Cryoplant continues cooling unless a warm-up is planned
• Vacuum is held to protect surfaces for a fast restart

End state

The shutdown ends in either a cold standby (ready to restart quickly) or a warm state for maintenance that requires coil warm-up. Residual and decay heat continue to be removed by the cooling systems throughout. The sequence is engineered at design stage against the frozen machine.