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By taking the National Ignition Facility(NIF) from the USA and the Laser Megajoule(LMJ) from the France for examples,this paper analyzes the general layout and general structure engineering features of Inertial Confinement Fusion(ICF) laser facility.NIF is designed with a U-shaped building layout,and it not only can provide an optimum laser experimental equipment configuration but also allow the equipment to attach a second target chamber in future.The bundles of LMJ are arranged in an in-line building.Its layout decreases the optical path-length between the output of each beamline and the focusing system also provides an option for a second target chamber exists.The paper suggests that the general layout of an ICF laser facility should meet the requirements of the physical experimental purposes and should be characterized by operation stability,good integration and higher maintainability.Furthermore,it should design convenient interfaces for future development.In overall design of the equipment,optical elements are packaged into a optical-mehanical assemblies,and replaceable units(LRUs) are assembled with kinematic mounts.The general structure of ICF design should match the arrangement of the laser beams in structural layout and configuration.Moreover,the structure design can not dispense with the function,stability and cleanliness.The assignments of general structure design should meet the requirements of the installation and localization,integration and debugging,operation and maintenance of the optical components and the physical/optical diagnostic equipment.

To assure the pointing accuracy in a shooting target to be better than 30 μm for the Shen Guang Ⅲ(SGⅢ)facility,the switchyard of target area for the facility was designed and the rigid frame and transport mirrors in the switchyard were optimized to improve their stability.In design,the reinforced concrete was used to support the switchyard,and the tilted supports were added in the steel frame of switchyard to decrease and distribute the mass load reasonably.Furthermore,the herringbone supports were firmed to local horizontal beams.The transport mirror supports were also designed,in which their foundational frequencies were much higher than that of the swichyard.By above ways,the angle shifts of transmission mirrors in random broadband vibration can be suppressed successfully.The mechanical analysis of range structure by Finite Element Analysis(FEA) indicates that 87% of transport mirrors show their angle shifts less than 0.48 μrad.According to the relation between the rotation drifts of the optics components and the positioning errors of optical path,it can be seen that the rotation drifts of the transmission mirrors could meet the stability requirements for the positioning error of each single optical path not more than 12.9 μm.