The appearance of soft x ray multilayer reflectence mirrors is an important event in x ray optics. It reformed the coventional grazing incidence method of reflecting x ray,and made it possible to reflect x ray in normal incidence way. It moves x ray optics forward greatly. Because soft x ray multilayer mirrors have high reflectivity and strip filter function, their applying territories are expanded contimuously. Various fields in x ray optics grow strong demands for them.In the longer wavelength(r>10nm) of soft x ray region(1nm |