High speed numerical control of a laser beam for a laser plasma injector

A system which enables a closed line magnetic confinement device to be filled with a laser-produced hydrogen plasma has been constructed. The design and initial performance of this system using targets 0.25 mm in diameter is reported here. The device moves the laser focus to intercept an injected pellet within a specified target area. The system detects the path of the pellet after launching, electronically predicts its trajectory, and deflects mirrors to a position that will move the laser focus to intercept the pellet within the target area. Glass pellets were used to commission the system and all that passed through the detector area were successfully intercepted.