Horizontal homing laser for high repetitive inertial fusion

Abstract

For the commercial laser inertial fusion energy (IFE) reactor, a highly repetitive operation in which many fuel pellets must be illuminated by laser spots. One of the most efficient ways to achieve this is to control the laser pointing with following fluctuations of the target position. The paper shows a precise control of the laser pointing for horizontal direction with a repetition rate of 10 Hz. Free-falling test pellets of 1 mm in diameter have been illuminated by a laser spot of 1.6 mm in diameter with cancellation of horizontal fluctuation over 4 mm. The difference in centroid between the laser spot and the illuminated test pellets is 86 m as standard deviation. This corresponds to a 92% engagement within a 0.15 mm difference, which is a condition for a successful nuclear fusion at the Hamamatsu facility. This is the proof-of-principle demonstration of target-supply tracking and homing laser at a repetition rate of 10 Hz leading to a commercial reactor.