Study on Control Strategy of Structure Stability for the Shenguang-III Laser Facility

Abstract The Shenguang-III laser facility is the largest high-power solid-state laser facility in Asia and provides 48 laser beams for laser fusion. To satisfy the demands of physics experiments, all the laser beams are required to be accurately positioned on the target and the positioning error of all the laser beams should not exceed 30 μm (root mean square). The formidable challenge in the facility design is how to minimize drift errors and structure vibrations and place the optical elements in their ideal locations. In the paper, we focus on the control strategy of structure stability for the Shenguang-III laser facility. Firstly, we present the methodology of stability index allocation to obtain the design parameter of structure stability for the laboratory platform and each optical element. Then we discuss the factors influencing stability of optical elements and the control methodology. Finally, we measure the beam pointing error to prove the feasibility of strategy. The results show that the maximum drift of all the laser beams is 26 μm (root mean square), which is less than 30 μm and satisfies the stability demand.