FOCUSING HIGH-ENERGY X-RAYS BY COMPOUND REFRACTIVE LENSES

Compound lenses made from low-Z materials (e.g., Be, B, C, and Al) set up as a linear array of refractive lenses are proposed for submicrome ter focusing of high-energy x rays (>5 keV) in one or two dimensions. A theory of focusing based on Maxwell's equation and the Fresnel-Kirch hoff approach is presented. Compound refractive lenses were manufactur ed by drilling into an Al block a linear array of 200 closely spaced h oles 0.5 mm in diameter for linear focusing and two crossed arrays of 100 holes each for point focusing. Focal spots of 3.7 mu m and 8 mu m x 18 mu m were obtained at 30 keV for linear and two-dimensional lense s, respectively. Different technologies of manufacturing and possible applications of the proposed lenses are discussed. (C) 1998 Optical So ciety of America.