A Multilayer X-Ray Mirror For Solar Photometric Imaging Flown On A Sounding Rocket

We discuss the flight of a multilayer-coated mirror on a sounding rocket experiment on March 17, 1988, which was used to obtain photometric images of the Sun just prior to solar eclipse. This 1.5" superpolished mirror was coated with 17 layer-pairs of Mo/Si at the Lockheed Palo Alto Research Laboratory, and achieved a peak reflectivity of 33 percent at a wavelength of 171 A; the mirror passband was 13 A FWHM. The spherical mirror, having a focal length of 0.75 m, formed an image of the Sun at 2.3 degrees off-axis directly onto a 128 x 128 microchannel plate CODACON detector. This detector and the companion EUV spectrometer experiment were built at the University of Colorado. Eight full-disk images of the Sun were obtained by this XUV imager. Our aim was to obtain absolutely-calibrated photometry of solar structures, rather than the higher resolution photography we could have achieved with film. Images obtained were of excellent quality and are being analyzed together with coordinated ground-based, eclipse coronagraph observations and radio maps taken at the VLA and Greenbank.