We discuss a systematic effect associated with measuring polarization with a continuously rotating half-wave plate (HWP). The effect was identified with the data from the E and B Experiment, which was a balloon-borne instrument designed to measure the polarization of the cosmic microwave background (CMB) as well as that from Galactic dust. The data show polarization fractions larger than 10%, while less than 3% were expected from instrumental polarization. We give evidence that the excess polarization is due to detector nonlinearity in the presence of a continuously rotating HWP. The nonlinearity couples intensity signals to polarization. We develop a map-based method to remove the excess polarization. Applying this method to the 150 (250) GHz band data, we find that 81% (92%) of the excess polarization was removed. Characterization and mitigation of this effect are important for future experiments aiming to measure the CMB B-modes with a continuously rotating HWP.

Intensity-coupled Polarization in Instruments with a Continuously Rotating Half-wave Plate / Didier, J.; Miller, A. D.; Araujo, D.; Aubin, F.; Geach, C.; Johnson, B.; Korotkov, A.; Raach, K.; Westbrook, B.; Young, K.; Aboobaker, A. M.; Ade, P.; Baccigalupi, C.; Bao, C.; Chapman, D.; Dobbs, M.; Grainger, W.; Hanany, S.; Helson, K.; Hillbrand, S.; Hubmayr, J.; Jaffe, A.; Jones, T. J.; Klein, J.; Lee, A.; Limon, M.; Macdermid, K.; Milligan, M.; Legault, Pascale; Reichborn-Kjennerud, B.; Sagiv, I.; Tucker, C.; Tucker, G. S.; Zilic, K.. - In: THE ASTROPHYSICAL JOURNAL. - ISSN 0004-637X. - 876:1(2019), pp. 1-14. [10.3847/1538-4357/ab0f36]

Intensity-coupled Polarization in Instruments with a Continuously Rotating Half-wave Plate

Baccigalupi, C.;Jaffe, A.;Lee, A.;Limon, M.;Pascale, E.;
2019-01-01

Abstract

We discuss a systematic effect associated with measuring polarization with a continuously rotating half-wave plate (HWP). The effect was identified with the data from the E and B Experiment, which was a balloon-borne instrument designed to measure the polarization of the cosmic microwave background (CMB) as well as that from Galactic dust. The data show polarization fractions larger than 10%, while less than 3% were expected from instrumental polarization. We give evidence that the excess polarization is due to detector nonlinearity in the presence of a continuously rotating HWP. The nonlinearity couples intensity signals to polarization. We develop a map-based method to remove the excess polarization. Applying this method to the 150 (250) GHz band data, we find that 81% (92%) of the excess polarization was removed. Characterization and mitigation of this effect are important for future experiments aiming to measure the CMB B-modes with a continuously rotating HWP.
876
1
1
14
54
https://arxiv.org/abs/1711.01314
Didier, J.; Miller, A. D.; Araujo, D.; Aubin, F.; Geach, C.; Johnson, B.; Korotkov, A.; Raach, K.; Westbrook, B.; Young, K.; Aboobaker, A. M.; Ade, P.; Baccigalupi, C.; Bao, C.; Chapman, D.; Dobbs, M.; Grainger, W.; Hanany, S.; Helson, K.; Hillbrand, S.; Hubmayr, J.; Jaffe, A.; Jones, T. J.; Klein, J.; Lee, A.; Limon, M.; Macdermid, K.; Milligan, M.; Legault, Pascale; Reichborn-Kjennerud, B.; Sagiv, I.; Tucker, C.; Tucker, G. S.; Zilic, K.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11767/111366
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