Joint of back-support in large aperture transport mirrors

The wavefront distortion can directly influence on the optics quality of laser beam in ICF laser facility. The gravity is one of the major factors that cause the wavefront distortion. The back-support technology of the large aperture transport mirror has been developed to lessen the wavefront distortion caused by gravity. In the back-support technology, a joint structure between the mirror and the metal back-support has been developed. The requirement of joint is that the firm connection is realized with less wavefront distortion introduced. The adhesive structure and expanding mandrel structure have been analyzed and tested. The back-support of transport mirror in target area use the expanding mandrel for the reasons of the technics and fundamental frequency. The choice of material, the calculation force of clamp, the test of tensile, and the wavefront distortion analysis of transport mirror have been developed. The results show that the expanding mandrel can be used for the back-support of the large aperture transport mirror.