Arthur B. C. Walker

Design of a Normal Incidence Multilayer Imaging X-Ray Microscope

Abstract Normal incidence multilayer Cassegrain x-ray telescopes were flown on the Stanford/ MSFC Rocket X-Ray Spectroheliograph. These instruments produced high spatial resolution images of the Sun and conclusively demonstrated that doubly reflecting multilayer x-ray optical systems are feasible. The images indicated that aplanatic imaging soft x-ray/EUV microscopes should be achievable using multilayer optics technology. We have designed a doubly reflecting normal incidence multilayer imaging x-ray microscope based on the Schwarzschild configuration. The Schwarzschild microscope utilizes two spherical mirrors with concentric radii of curvature which are chosen such that the third-order spherical aberration and coma are minimized. We discuss the design of the microscope and the results of the optical system ray trace analysis which indicates that diffraction-limited performance with 600 A spatial resolution should be obtainable over a 1 mm field of view at a wavelength of 100 A. Fabrication of several imaging soft x-ray microscopes based upon these designs, for use in conjunction with x-ray telescopes and laser fusion research, is now in progress. High resolution aplanatic imaging x-ray microscopes using normal incidence multilayer x-ray mirrors should have many important applications in advanced x-ray astronomical instrumentation, x-ray lithography, biological, biomedical, metallurgical, and laser fusion research.

Astronomical EUV/x-ray observatories on the moon

In quest of higher angular resolution and broader spectral coverage, solar physics was the first astronomical discipline to obtain observations from rockets, and later from satellites. Solar physicists have also been pioneers in the application of new imaging technologies. For example, the first high resolution astronomical x‐ray images obtained with grazing incidence optics were of the sun; more recently, the first high resolution astronomical soft x‐ray /EUV images obtained with normal incidence multilayer x‐ray imaging techniques have also been of the sun.