Meter-scale large-aperture gratings are essential in petawatt-class picosecond laser systems.Their grating mounts must support heavy-load arrays and high alignment accuracy due to high energy density and long beam pat...Meter-scale large-aperture gratings are essential in petawatt-class picosecond laser systems.Their grating mounts must support heavy-load arrays and high alignment accuracy due to high energy density and long beam paths.However,nonlinear errors from parasitic motions and transmission gaps can significantly degrade precision.This study presents a kinetostatic modeling and error calibration framework for the grating mount,incorporating an improved particle swarm optimization(PSO) algorithm.The nonlinear error model combines energy-based and pseudo-rigid-body methods,with equivalent representations of structural gaps and parasitic motions.To capture multi-source nonlinear interactions,a global-dynamic multi-subgroup PSO enhances calibration via coordinated global exploration and local refinement.Experiments indicate that,compared with conventional models,first-round compensation reduces average errors by over65.4%,79.8% and 74.8% in rotation,tip and tilt,respectively.The method integrates nonlinear pose modeling,unified gap representation and an enhanced PSO strategy,offering an effective solution for error compensation in meter-scale,heavy-load compliant mechanisms.展开更多
In this paper, we review the status of the multifunctional experimental platform at the National Laboratory of High Power Laser and Physics(NLHPLP). The platform, including the SG-II laser facility, SG-II 9th beam, SG...In this paper, we review the status of the multifunctional experimental platform at the National Laboratory of High Power Laser and Physics(NLHPLP). The platform, including the SG-II laser facility, SG-II 9th beam, SG-II upgrade(SG-II UP) facility, and SG-II 5 PW facility, is operational and available for interested scientists studying inertial confinement fusion(ICF) and a broad range of high-energy-density physics. These facilities can provide important experimental capabilities by combining different pulse widths of nanosecond, picosecond, and femtosecond scales. In addition, the SG-II UP facility, consisting of a single petawatt system and an eight-beam nanosecond system, is introduced including several laser technologies that have been developed to ensure the performance of the facility. Recent developments of the SG-II 5 PW facility are also presented.展开更多
To establish the mechanism of surface change in a continuous polishing system, an ideal mathematical model is built based on Winkler's hypothesis and the Preston equation. The basic features of the model are the c...To establish the mechanism of surface change in a continuous polishing system, an ideal mathematical model is built based on Winkler's hypothesis and the Preston equation. The basic features of the model are the change rates in the surface peak–valley(PV) values of the workpiece, conditioning disk and pitch lap, rather than the specific surface shapes. In addition, an equilibrium state exists in the system, indicating that the surface change rates are all zero. Under equilibrium, the surface of the lap could remain flat, and it is insensitive to the surface error of the workpiece. These characteristics lay the theoretical foundations for high-efficiency and high-precision polishing. The methods to obtain an equilibrium state with flat surfaces are then proposed and confirmed experimentally. High-precision surfaces better thanλ/10(λ = 632.8 nm) are consistently produced experimentally.展开更多
基金supported by the Project of Chinese Academy of Sciences(Grant No.23XR0256)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos.XDA25020203,XDA25020101 and XDA25020103)
文摘Meter-scale large-aperture gratings are essential in petawatt-class picosecond laser systems.Their grating mounts must support heavy-load arrays and high alignment accuracy due to high energy density and long beam paths.However,nonlinear errors from parasitic motions and transmission gaps can significantly degrade precision.This study presents a kinetostatic modeling and error calibration framework for the grating mount,incorporating an improved particle swarm optimization(PSO) algorithm.The nonlinear error model combines energy-based and pseudo-rigid-body methods,with equivalent representations of structural gaps and parasitic motions.To capture multi-source nonlinear interactions,a global-dynamic multi-subgroup PSO enhances calibration via coordinated global exploration and local refinement.Experiments indicate that,compared with conventional models,first-round compensation reduces average errors by over65.4%,79.8% and 74.8% in rotation,tip and tilt,respectively.The method integrates nonlinear pose modeling,unified gap representation and an enhanced PSO strategy,offering an effective solution for error compensation in meter-scale,heavy-load compliant mechanisms.
基金supported by International Partnership Program of Chinese Academy of Sciences(No.181231KYSB20170022)the Key Projects of International Cooperation in Chinese Academy of Sciences
文摘In this paper, we review the status of the multifunctional experimental platform at the National Laboratory of High Power Laser and Physics(NLHPLP). The platform, including the SG-II laser facility, SG-II 9th beam, SG-II upgrade(SG-II UP) facility, and SG-II 5 PW facility, is operational and available for interested scientists studying inertial confinement fusion(ICF) and a broad range of high-energy-density physics. These facilities can provide important experimental capabilities by combining different pulse widths of nanosecond, picosecond, and femtosecond scales. In addition, the SG-II UP facility, consisting of a single petawatt system and an eight-beam nanosecond system, is introduced including several laser technologies that have been developed to ensure the performance of the facility. Recent developments of the SG-II 5 PW facility are also presented.
基金supported by grants from the Chinese and Israeli Cooperation Project on High-power Laser Technology(2010DFB70490)
文摘To establish the mechanism of surface change in a continuous polishing system, an ideal mathematical model is built based on Winkler's hypothesis and the Preston equation. The basic features of the model are the change rates in the surface peak–valley(PV) values of the workpiece, conditioning disk and pitch lap, rather than the specific surface shapes. In addition, an equilibrium state exists in the system, indicating that the surface change rates are all zero. Under equilibrium, the surface of the lap could remain flat, and it is insensitive to the surface error of the workpiece. These characteristics lay the theoretical foundations for high-efficiency and high-precision polishing. The methods to obtain an equilibrium state with flat surfaces are then proposed and confirmed experimentally. High-precision surfaces better thanλ/10(λ = 632.8 nm) are consistently produced experimentally.
