Method for collimating capillary tube in laser electron accelerator

The invention relates to a method for collimating capillary tube in laser electron accelerator, including the steps: (1) focal position converging light beams is found, and a concentric ring plate concentric with the converged light beam is arranged; (2) position of micropore aperture is determined; (3) a reflecting mirror, a CCD camera and a computer are arranged; (4) the position of the micropore aperture is accurately adjusted; (5) a capillary tube is arranged, and collimation of the capillary tube and main laser is accurately adjusted. The method of the invention has the characteristics of clear principle, convenient and fast operation and accurate collimation adjustment. The method also can dynamically detect collimation changing process of the capillary tube and main laser in a target chamber evacuation process, and the invention also can be used for regulating and monitoring collimation of large size light beam after being focused with any microchannel.