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Table 1: Summary of EUV wavelengths with corresponding ion lines and temperatures (T) planned for the AIA instrument. The bandwidth values are based on experimental performance of the multilayer coatings discussed later in this manuscript. Part of the material in this Table is courtesy of LMSAL.

Table 1 Summary of EUV wavelengths with corresponding ion lines and temperatures (T) planned for the AIA instrument. The bandwidth values are based on experimental performance of the multilayer coatings discussed later in this manuscript. Part of the material in this Table is courtesy of LMSAL.

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Multilayer film parameters for each channel have been uniquely optimized to satisfy criteria for peak reflectivity (throughput), suppression of nearby emission lines, lifetime stability and stress properties. Another crucial requiremen for efficient AIA imaging is meeting the wavelength specifications across each multilayer-coated flight optic pair, whicl in turn depends on precise thickness control of the multilayer thin film across each curved mirror surface. Experimenta results on all aforementioned aspects of the EUV multilayer optics for AIA are presented in this manuscript. Figure 1: (a) Schematic drawing of the front view of the four AIA telescopes with their shutters open. Each telescope is shown with two wavelength channels and a dedicated guide telescope on top. All wavelength units are Angstroms. (b) Interior components of each telescope. Drawings are courtesy of Lockheed Martin Solar and Astrophysics Lab (LMSAL).
Multilayer film parameters for each channel have been uniquely optimized to satisfy criteria for peak reflectivity (throughput), suppression of nearby emission lines, lifetime stability and stress properties. Another crucial requiremen for efficient AIA imaging is meeting the wavelength specifications across each multilayer-coated flight optic pair, whicl in turn depends on precise thickness control of the multilayer thin film across each curved mirror surface. Experimenta results on all aforementioned aspects of the EUV multilayer optics for AIA are presented in this manuscript. Figure 1: (a) Schematic drawing of the front view of the four AIA telescopes with their shutters open. Each telescope is shown with two wavelength channels and a dedicated guide telescope on top. All wavelength units are Angstroms. (b) Interior components of each telescope. Drawings are courtesy of Lockheed Martin Solar and Astrophysics Lab (LMSAL).
Figure 2: Summary of predicted multilayer reflectance and filter transmission of the AIA instrument
Figure 2: Summary of predicted multilayer reflectance and filter transmission of the AIA instrument
Figure 3: ['-optimization results on Mo/Si coatings are shown for (a) 211.3 A, (b) 193.5 A, (c) 171.1 A and (d) 131 A channels. Examples of peak and out-of-band Fe ion lines are shown in (a), (b) for the 211.3 and 193.5 A channels, respectively. The highlighted I’-values indicate the selected T for each channel, and the number of Mo/Si bilayers (N) and Si topmost layer thickness (dsica,) are also noted in each plot. EUV reflectance measurements were performed at beamline 6.3.2. of the ALS, with the sample at 0 = 85° angle of incidence, defined from the grazing direction.
Figure 3: ['-optimization results on Mo/Si coatings are shown for (a) 211.3 A, (b) 193.5 A, (c) 171.1 A and (d) 131 A channels. Examples of peak and out-of-band Fe ion lines are shown in (a), (b) for the 211.3 and 193.5 A channels, respectively. The highlighted I’-values indicate the selected T for each channel, and the number of Mo/Si bilayers (N) and Si topmost layer thickness (dsica,) are also noted in each plot. EUV reflectance measurements were performed at beamline 6.3.2. of the ALS, with the sample at 0 = 85° angle of incidence, defined from the grazing direction.
Figure 4: TEM images of a !=0.16 multilayer selected for the 193.5 A channel, demonstrating the amorphous structure of Si and Mo layers.
Figure 4: TEM images of a !=0.16 multilayer selected for the 193.5 A channel, demonstrating the amorphous structure of Si and Mo layers.
Figure 5: Measured stress vs. I for all Mo/Si films presented in Figure 3. The arrows indicate the selected I value for each of the four AIA channels. Stress for each film was measured within 4 days from deposition.
Figure 5: Measured stress vs. I for all Mo/Si films presented in Figure 3. The arrows indicate the selected I value for each of the four AIA channels. Stress for each film was measured within 4 days from deposition.
Lifetime stability results for Mo/Y and SiC/Mg samples in ambient environment are plotted in Figure 7. Long-term annealing and proton irradiation experiments on these samples are discussed in Ref. 21.
Lifetime stability results for Mo/Y and SiC/Mg samples in ambient environment are plotted in Figure 7. Long-term annealing and proton irradiation experiments on these samples are discussed in Ref. 21.
Figure 7: Lifetime stability results are plotted vs. time (since deposition) for the Mo/Y (93.9 A) and SiC/Mg (303.8 and 335.4 A) multilayers, measured at the CAL reflectometer. Figure 6: (a) Comparison of Mo/Si, SiC/Si and SiC/Mg performance at 303.8 and 335.4 A. (b) Experimental results from the I optimization at 335.4 A, with the selected value [=0.22 highlighted. The total number of bilayers is N=40 and the topmost layer in the film is SiC, for all SiC/Mg samples. All reflectance measurements were performed at the CAL facility.
Figure 7: Lifetime stability results are plotted vs. time (since deposition) for the Mo/Y (93.9 A) and SiC/Mg (303.8 and 335.4 A) multilayers, measured at the CAL reflectometer. Figure 6: (a) Comparison of Mo/Si, SiC/Si and SiC/Mg performance at 303.8 and 335.4 A. (b) Experimental results from the I optimization at 335.4 A, with the selected value [=0.22 highlighted. The total number of bilayers is N=40 and the topmost layer in the film is SiC, for all SiC/Mg samples. All reflectance measurements were performed at the CAL facility.
where z is the surface height, r is the radial position defined from the optical axis of each mirror, R is the radius of curvature and K is the conic constant. Table 2 summarizes the values of R and K, as well as the mirror and clear aperture (CA) radii and incidence angles for the AIA mirrors. As is noted in Table 2, the angles of incidence for both mirrors are very close to the normal direction (90°) and vary only slightly across the CA. Therefore, uniform multilayer coatings were prescribed for both primary and secondary mirrors of the AIA instrument. Table 2: AIA telescope mirror parameters. Angles of incidence are defined from the grazing direction. Optical design by NV. A. Podgorski (Smithsonian Astrophysical Observatory).
where z is the surface height, r is the radial position defined from the optical axis of each mirror, R is the radius of curvature and K is the conic constant. Table 2 summarizes the values of R and K, as well as the mirror and clear aperture (CA) radii and incidence angles for the AIA mirrors. As is noted in Table 2, the angles of incidence for both mirrors are very close to the normal direction (90°) and vary only slightly across the CA. Therefore, uniform multilayer coatings were prescribed for both primary and secondary mirrors of the AIA instrument. Table 2: AIA telescope mirror parameters. Angles of incidence are defined from the grazing direction. Optical design by NV. A. Podgorski (Smithsonian Astrophysical Observatory).
Figure 8: Multilayer thickness uniformity results achieved on curved, test AIA substrates (spherical approximations of the actual AIA mirrors). Demonstrated uniformity is well within the specifications (illustrated by the dotted guidelines in the bottom plots) across the CA of each mirror. The multilayer coating is Mo/Y reflecting near 93.9 A, performed at CAL and measured with the CAL reflectometer.
Figure 8: Multilayer thickness uniformity results achieved on curved, test AIA substrates (spherical approximations of the actual AIA mirrors). Demonstrated uniformity is well within the specifications (illustrated by the dotted guidelines in the bottom plots) across the CA of each mirror. The multilayer coating is Mo/Y reflecting near 93.9 A, performed at CAL and measured with the CAL reflectometer.
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