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arXiv · 1801.08971

Polarized Beam Patterns from a Multi-Moded Feed For Observations of the Cosmic Microwave Background

A. Kogut·D. J. Fixsen
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Abstract

We measure linearly polarized beam patterns for a multi-moded concentrator and compare the results to a simple model based on geometric optics. We convolve the measured co-polar and cross-polar beams with simulated maps of CMB polarization to estimate the amplitude of the systematic error resulting from the cross-polar beam response. The un-corrected error signal has typical amplitude of 3 nK, corresponding to inflationary B-mode amplitude r ~ 10^{-3}. Convolving the measured cross-polar beam pattern with maps of the CMB E-mode polarization provides a template for correcting the cross-polar response, reducing it to negligible levels.

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A. Kogut, D. J. Fixsen. 2018-01-26. Polarized Beam Patterns from a Multi-Moded Feed For Observations of the Cosmic Microwave Background. https://arxiv.org/abs/1801.08971

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