Development of the focus system for HeavenⅠ

This paper introduces the method of guiding the six KrF laser beams into target chamber and the development of focus system in MOPA angular multiplex system for HeavenⅠ. The six beams are focused to the vacuum target chamber by six planeconvex lenses. The focal spot on the target is measured by UV CCD camera, the diameter of the focal spot of six beams is 290μm, the focusing power density on the target is 8×1012W/cm2.