Polarized Beam Patterns from a Multimoded Feed for Observations of the Cosmic Microwave Background

Kogut, A ; Fixsen, D J

关键词: BEAMS (RADIATION);    CROSS POLARIZATION;    COSMIC MICROWAVE BACKGROUND RADIATION;    POLARIZATION (WAVES);    RADIATION DISTRIBUTION;    CONCENTRATORS;    ERROR SIGNALS;    FLAT PATTERNS;    MONTE CARLO METHOD;    SYSTEMATIC ERRORS;   

RP-ID  :  GSFC-E-DAA-TN70846

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来源: NASA Technical Reports Server

【 摘 要 】

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(exp -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.