1. EPIC Medium-Scale Optical Design Huan Tran Brad Johnson Mark Dragovan April 2009

2. EPIC-IM optical layout

3. EPIC-IM optical properties Crossed Dragone ABS, Clover, QUIXOTE, QUIET …. Unprecedented Large FOV 30x20 degrees Extreme Compact design Maximize resolution/throughput in shroud Telecentric NO refractive elements

4. EPIC-IM optical properties “force” telecentric focal plane => cold aperture Oversize mirrors

5. EPIC-IM aberration performance Elliptical focal plane – Limited by vignetting in Y – Limited by aberration in X Multiband – High Frequencies in center – 30—800 GHz 11,000 bolometers 30 deg/ 160 cm 150 GHz 30 GHz 850 GHz

6. EPIC-IM cold vs warm

7. Main Beam Simulations Beam shapes – No Refracting elements – Calculated with Perfect Gaussian Feed horns – Calculated for each “Hex” Polarized beam-scale distortions – Fit Gaussians to beams – Compare to benchmarks

8. PO co and cross–pol beams for single feed

9. PO vs GO sanity check 30 GHz beam, from Grasp 9 Spot diagram, from Zemax

10. Main beam effects vs benchmark Fig. 6.4 Histograms of main beam effects. Refer to Section 5.4.1 for definitions of each effect. Histograms are color coded by frequency. Colored Arrows denote the frequency dependant goals from table 5.4. Goals for some EPIC-IM mirrors alone are below benchmarks w/o modulation

11. Sidelobes Analyzed with Physical Optics(PO) an Geometric Theory of Diffraction (GTD) Aperture Integration Method – Optics box Galaxy Convolution

12. EPIC-IM straylight

13. EPIC-IM farsidelobes Co-pol beam, no baffling ~15d simulation time

14. Calculate Equiv J Aperture Integration method Set J =0 outside 28d sim time

15. Polarized Far Sidelobes (QT 2 + UT 2 + VT 2 ) 1/2 2 x15d sim time

16. Galactic Contamination In order to evaluate the effect of the signal from the far sidelobes, we convolve the qt beam maps with a 150 GHz sky model. The beam patterns have the primary beam masked, so only the response to the sidelobes are evident in the output. The sky data is an all sky map at long wavelengths (150 GHz). Since the beam is asymmetric, it is necessary to rotate the beam with respect to the sky at each point to get the complete convolution. The convolutions were done using the totalconvolver code developed by the Planck community. (Gorski et. al.) M.Dragovan

17. (above) The 150 GHz sky map with which the beams are convolved. Units are log(uK). (below) The results of the convolution, qt beam with the above sky. Units are (uK). M.Dragovan

18. In order to further quantify this result, we make two histograms: the number of pixels with a given intensity (left plot), and the integrated histogram giving the total number of pixels less than a given intensity (right plot). This is similar to the plots that are shown for site surveys. By inspection one can see that fully 90% of the pixels are <0.2nK. M.Dragovan Goal 1nK

19. GTD and Polarization of sidelobes Our Far sidelobe simulations were for 3.25 –f –, but

20. Conclusions EPIC-IM has enormous throughput Systematic beam effects are below benchmark Sidelobes are manageable – More analysis time required to be sure