The Stanford/Msfc Multi-Spectral Solar Telescope Array

Abstract

The development of multilayer optics has profound implications for soft x-ray/EUV (XUV) astronomy. During the October 1987 flight of the Stanford/MSFC Rocket X-Ray Spectroheliograph, narrow wavelength band low scatter soft x-ray/EUV spectroheliograms were obtained with 1 arc second spatial resolution at λ~ 173 A (Fe IX, Fe X) and at X, 256 A (He II). Although the Cassegrain telescopes used in this experiment were small (63.5 mm diameter) and utilized spherical rather than paraboloidal/hyperboloidal mirrors, the images produced exceed in quality any XUV spectroheliograms previously obtained with either normal or grazing incidence techniques. We describe a new rocket spectroheliograph instrument, the Multi-Spectral Solar Telescope Array (MSSTA), that is currently being prepared for launch in September 1989. This instrument will utilize true Ritchey-Chretien optics of 127 mm diameter and parabolic Herschelian optics of 40 mm diameter, which will allow spectroheliograms to be obtained over the soft x-ray/EUV/VUV spectral range (40 Å - 1550 Å). The performance of this new instrument should definitely demonstrate the unique combination of ultra-high spatial resolution and spectral differentiation which multilayer optics afford for astronomical observations. The MSSTA will also represent the first astronomical use of an important new optical device, the multilayer grating. The MSSTA should obtain unprecedented information regarding the structure and dynamics of the solar atmosphere in the temperature range 104 K to 107 K.