• DOI:10.1117/1.JATIS.4.1.014006
• Corpus ID: 73553244

Polarized beam patterns from a multimoded feed for observations of the cosmic microwave background

@article{Kogut2018PolarizedBP,
  title={Polarized beam patterns from a multimoded feed for observations of the cosmic microwave background},
  author={Alan J. Kogut and Dale J. Fixsen},
  journal={Journal of Astronomical Telescopes, Instruments, and Systems},
  year={2018},
  volume={4}
}

• A. Kogut, D. Fixsen
• Published 26 January 2018
• Physics
• Journal of Astronomical Telescopes, Instruments, and Systems

Abstract. We measure linearly polarized beam patterns for a multimoded concentrator and compare the results to a simple model based on geometric optics. We convolve the measured copolar and crosspolar beams with simulated maps of cosmic microwave background (CMB) polarization to estimate the amplitude of the systematic error resulting from the crosspolar beam response. The uncorrected error signal has typical amplitude of 3 nK, corresponding to inflationary B-mode amplitude r∼10−3. Convolving the measured crosspolar beam pattern with maps of the CMB E-mode polarization provides a template for correcting the crosspolar response, reducing it to negligible levels.