The quench launcher is designed to turn off or quench as the launch package approaches the center. Importantly, it is a non-contact design, with a central carrier sleeve (acting as the armature) supported magnetically. The drive coils (acting as the stator) are located along the vacuum tube. All the quench launcher’s coils are powered up the length of the launch tube prior to launch and then uses the disruption from the passing armature’s strong magnetic field to quench, or turn off, coils as it moves forward.
The devil lies in the dynamic details of the rapidly changing fields as the carrier sleeve accelerates forward, and of course, in the performance of quench switching.
The simple diagram below describes the general drive field layout. As the carrier sleeve (armature) moves forward in the launcher the currents in both the launcher (stator) coils and the armature coils are changed by magnetic interaction with each other.