Development and testing of EUV multilayer coatings for the Atmospheric Imaging Assembly instrument aboard the Solar Dynamics Observatory Regina Soufli *1 , David L. Windt 2 , Jeff C. Robinson 1 , Sherry L. Baker 1 , Eberhard Spiller 1 , Franklin J. Dollar 3 , Andrew L. Aquila 3 , Eric M. Gullikson 3 , Benjawan Kjornrattanawanich 4 , John F. Seely 5 , Leon Golub 6 1 Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550, USA 2 Columbia Astrophysics Laboratory, New York, NY 10027, USA 3 Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA 4 Universities Space Research Association, National Synchrotron Light Source, Beamline X24C, Brookhaven National Laboratory, Upton, NY 11973, USA 5 Space Science Division, Naval Research Laboratory, Washington, DC 20375, USA 6 Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA ABSTRACT We present experimental results on the development and testing of the extreme ultraviolet (EUV) reflective multilayer coatingsthat will be used in the Atmospheric Imaging Assembly (AIA) instrument. The AIA, comprising four normal- incidence telescopes, is one of three instruments aboard the Solar Dynamics Observatory mission, part of NASA’s Living with a Star program, currently scheduled for launch in 2008. Seven different multilayer coatings will be used, covering the wavelength region from 93.9 to 335.4 Å. Keywords: Solar Dynamics Observatory, Atmospheric Imaging Assembly, EUV, multilayer coatings, solar physics 1. INTRODUCTION The AIA instrument aboard the Solar Dynamics Observatory (Ref.1) is designed to provide an unprecedented view of the solar corona, taking images that span at least 1.3 solar diameters in multiple wavelengths nearly simultaneously, at a resolution of 1 arcsecond, field of view exceeding 41 arcminutes and at a cadence of 10 seconds or better. AIA will produce essential data for quantitative studies of the evolving coronal magnetic field and its plasma. These data will be used to significantly improve the understanding of the physics behind the activity displayed by the Sun's atmosphere, which drives space weather in the heliosphere and in planetary environments. The AIA is composed of four telescopes, each including a primary-secondary pair of mirrors operating at near-normal angles of incidence. Each telescope produces images at two different wavelengths accomplished by two different multilayer coatings acting as Bragg reflectors, deposited across two respective D-shaped areas on each mirror. In this manner, imaging at a total of eight channels -seven in the EUV and one in the UV range- is achieved. In this talk we are discussing the development of multilayer coatings for the seven EUV (93.9, 131, 171.1, 193.5, 211.3, 303.8 and 335.4 Å) channels of the AIA instrument, shown in Figures 1(a), 2. EUV wavelengths were selected in order to observe the solar corona at specific temperatures corresponding to Fe and He ion lines, as shown in Table 1 and Figure 2. It is worthwhile noting that two of the AIA channels (93.9, 131 Å) have never been implemented in earlier solar missions and thus will be observed for the very first time with AIA. Two additional AIA wavelengths (211.3, 335.4 Å) were not included in the earlier SOHO and TRACE missions. The predicted response from the EUV multilayer coatings for AIA is plotted in Figure 2, combined with the transmission of the Zr and Al filters used in the instrument. The pairing of wavelengths in each telescope is such that either the Zr or the Al filter is sufficient for selection of one of the wavelengths in the pair and suppression of the * regina.soufli@llnl.gov ; phone 925-422-6013; fax 925-423-1488 Solar Physics and Space Weather Instrumentation, edited by Silvano Fineschi, Rodney A. Viereck, Proc. of SPIE Vol. 5901, 59010M, (2005) · 0277-786X/05/$15 · doi: 10.1117/12.617370 Proc. of SPIE Vol. 5901 59010M-1