In these proceedings, we summarize our in-field evaluation of temperature-to-polarization leakage associated with the use of a continuously-rotating, ambient-temperature half-wave plate (HWP) on the Atacama B-Mode Search (ABS) experiment. Using two seasons of data, we demonstrate scalar leakage of ∼ 0.01%. This is consistent with model expectations and an order of magnitude better than any previously-reported leakage. We constrain higher-order dipole and quadrupole leakage terms to be < 0.06% (95% confidence). Without any mitigation from scan cross-linking or boresight rotation, this corresponds to an upper limit on systematic errors in the tensor-to-scalar ratio r ;S 0.01. The HWP significantly reduces temperature-to-polarization leakage systematic errors for ABS and shows the promise of fast polarization modulation with HWPs for future experiments. Full details can be found in Ref. 1.

Date Published: 19 July 2016
PDF: 8 pages
Proc. SPIE 9914, Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VIII, 991415 (19 July 2016); doi: 10.1117/12.2232711

Published in SPIE Proceedings Vol. 9914:
Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VIII
Wayne S. Holland; Jonas Zmuidzinas, Editor(s)