Disruption

A disruption is a violent event that terminates a magnetically confined plasma, usually the consequence of a rapidly growing instability, often of the MHD type. In a disruption, the temperature drops drastically and heat and particles are released from confinement on a short timescale and dumped on the vessel wall, causing damage in proportion to the stored energy. The loss of confinement is associated with the production of runaway electrons, which may also produce damage.

The magnetic effects of a disruption (associated with the sudden loss of the net plasma current) generates large magnetic forces on the metallic structures surrounding the plasma (the vessel, the coils, and the supporting structure), also known as Vertical Displacement Events, which may induce mechanical damage.

Disruption avoidance or mitigation is an important topic for ITER.

Due to the fact that in stellarators, confinement does not depend on the plasma current, disruptions are less severe or inexistent in such machines, which is a significant advantage for the design of a future reactor.