Permanent magnet structures for XUV image sensors

Several permanent magnet structures were designed to serve as light-weight, low-bulk field sources to guide the electron beams in X-ray/ultraviolet (XUV) image sensors. All weigh approximately a half-kilogram or less compared to the presently used structures of several kilograms. The field uniformity is on the order of a percent over the region traversed by the electron beam. Of the three structures described, all produce uniform fields over the required volume at low weight and bulk. The regular clad type is simplest and most rugged. The shifted-potential type is some 15% lighter. The semicylindrical type may be useful for low angles of XUV incidence, where compactness in the lateral dimension is required and where the required low temperatures are not a problem