Magnet Protection Interlocks
A hard-wired interlock chain guards the coils, tripping the supply and firing the dump whenever any monitored condition leaves its safe window.
Why a separate chain
Magnet protection is a safety function, so it does not rely on the ordinary control computer. A dedicated, often hard-wired or dedicated-logic interlock chain watches the conditions that could destroy a coil and acts within milliseconds, independent of software that might be busy or faulted. Its default state is safe: loss of power or signal trips protection rather than defeating it.
Monitored conditions
The chain aggregates quench-detection trips, cryogenic faults such as loss of flow or low helium level, over-current and over-voltage from the power supply, over-temperature of leads and joints, and cryostat vacuum loss. Any one condition outside its window opens the breaker and, where appropriate, commands the energy dump.
Coordinated response
A magnet trip is never isolated. Because the plasma depends on the field, the interlock simultaneously commands a controlled plasma termination, informs cryogenic control to expect boil-off, and inhibits heating and fueling. This coordination prevents a magnet fault from cascading into damage elsewhere, for example a plasma disruption onto plasma-facing components.
- Independent, fail-safe interlock logic
- Aggregates quench, cryo, supply, and vacuum faults
- Trips breaker and fires dump within milliseconds
- Commands plasma termination and inhibits actuators
Testing and integrity
Because the chain must work the one time it is needed, its channels are tested on a schedule, wired for continuous self-monitoring, and built with redundancy so a single component failure neither defeats protection nor causes a spurious trip. Trip logs feed post-event analysis. In the Kronos designs the interlock architecture is specified around the high stored energy of the breeder and burner coils and is part of the simulation and design basis rather than operating equipment.
The interlock is judged not by how often it fires but by never failing to fire when it must.