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Title: Systematic effects from an ambient-temperature, continuously rotating half-wave plate

Authors:
; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1324484
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Review of Scientific Instruments
Additional Journal Information:
Journal Volume: 87; Journal Issue: 9; Related Information: CHORUS Timestamp: 2016-12-26 01:19:43; Journal ID: ISSN 0034-6748
Publisher:
American Institute of Physics
Country of Publication:
United States
Language:
English

Citation Formats

Essinger-Hileman, T., Kusaka, A., Appel, J. W., Choi, S. K., Crowley, K., Ho, S. P., Jarosik, N., Page, L. A., Parker, L. P., Raghunathan, S., Simon, S. M., Staggs, S. T., and Visnjic, K.. Systematic effects from an ambient-temperature, continuously rotating half-wave plate. United States: N. p., 2016. Web. doi:10.1063/1.4962023.
Essinger-Hileman, T., Kusaka, A., Appel, J. W., Choi, S. K., Crowley, K., Ho, S. P., Jarosik, N., Page, L. A., Parker, L. P., Raghunathan, S., Simon, S. M., Staggs, S. T., & Visnjic, K.. Systematic effects from an ambient-temperature, continuously rotating half-wave plate. United States. doi:10.1063/1.4962023.
Essinger-Hileman, T., Kusaka, A., Appel, J. W., Choi, S. K., Crowley, K., Ho, S. P., Jarosik, N., Page, L. A., Parker, L. P., Raghunathan, S., Simon, S. M., Staggs, S. T., and Visnjic, K.. 2016. "Systematic effects from an ambient-temperature, continuously rotating half-wave plate". United States. doi:10.1063/1.4962023.
@article{osti_1324484,
title = {Systematic effects from an ambient-temperature, continuously rotating half-wave plate},
author = {Essinger-Hileman, T. and Kusaka, A. and Appel, J. W. and Choi, S. K. and Crowley, K. and Ho, S. P. and Jarosik, N. and Page, L. A. and Parker, L. P. and Raghunathan, S. and Simon, S. M. and Staggs, S. T. and Visnjic, K.},
abstractNote = {},
doi = {10.1063/1.4962023},
journal = {Review of Scientific Instruments},
number = 9,
volume = 87,
place = {United States},
year = 2016,
month = 9
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1063/1.4962023

Citation Metrics:
Cited by: 4works
Citation information provided by
Web of Science

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  • A continuously rotating half-wave plate (CRHWP) is a promising tool to improve the sensitivity to large angular scales in cosmic microwave background (CMB) polarization measurements. With a CRHWP, single detectors can measure three of the Stokes parameters, I, Q and U, thereby avoiding the set of systematic errors that can be introduced by mismatches in the properties of orthogonal detector pairs. We focus on the implementation of CRHWPs in large aperture telescopes (i.e. the primary mirror is larger than the current maximum half-wave plate diameter of ~0.5 m), where the CRHWP can be placed between the primary mirror and focalmore » plane. In this configuration, one needs to address the intensity to polarization (I→P) leakage of the optics, which becomes a source of 1/f noise and also causes differential gain systematics that arise from CMB temperature fluctuations. In this paper, we present the performance of a CRHWP installed in the {\scshape Polarbear} experiment, which employs a Gregorian telescope with a 2.5 m primary illumination pattern. The CRHWP is placed near the prime focus between the primary and secondary mirrors. We find that the I→P leakage is larger than the expectation from the physical properties of our primary mirror, resulting in a 1/f knee of 100 mHz. The excess leakage could be due to imperfections in the detector system, i.e. detector non-linearity in the responsivity and time-constant. We demonstrate, however, that by subtracting the leakage correlated with the intensity signal, the 1/f noise knee frequency is reduced to 32 mHz (ℓ ~ 39 for our scan strategy), which is very promising to probe the primordial B-mode signal. We also discuss methods for further noise subtraction in future projects where the precise temperature control of instrumental components and the leakage reduction will play a key role.« less
  • Three series of Cr-based mixed oxides (Cr-Co, Cr-Fe, and Cr-Ni oxides) with high specific surface areas and amorphous textures were synthesized using a novel sol-gel method. These mixed oxides, in comparison to their pure metal oxide (CrOx, Co3O4, FeOx and NiO) counterparts, display enhanced performance for catalytic oxidation of low-concentration NO at room temperature. The best performing catalysts achieve 100% NO conversion for ~30 h of operation at a high space velocity of 45,000 ml g-1 h-1. The amorphous structure was found to be critical for these catalysts to maintain high activity and durability. Control of Cr/M (M=Co, Fe andmore » Ni) molar ratio, nitrate precursor decomposition temperature and catalyst calcination temperature was key to the synthesis of these highly active catalysts.« less
  • We study the impact of the spectral dependence of the linear polarization rotation induced by an achromatic half-wave plate on measurements of cosmic microwave background polarization in the presence of astrophysical foregrounds. We focus on the systematic effects induced on the measurement of inflationary gravitational waves by uncertainties in the polarization and spectral index of Galactic dust. We find that for the experimental configuration and noise levels of the balloon-borne EBEX experiment, which has three frequency bands centered at 150, 250, and 410 GHz, a crude dust subtraction process mitigates systematic effects to below detectable levels for 10% polarized dustmore » and tensor-to-scalar ratio of as low as r = 0.01. We also study the impact of uncertainties in the spectral response of the instrument. With a top-hat model of the spectral response for each band, characterized by band center and bandwidth, and with the same crude dust subtraction process, we find that these parameters need to be determined to within 1 and 0.8 GHz at 150 GHz; 9 and 2.0 GHz at 250 GHz; and 20 and 14 GHz at 410 GHz, respectively. The approach presented in this paper is applicable to other optical elements that exhibit polarization rotation as a function of frequency.« less
  • The problem of determining the stress state in a plate subjected to thermal transient is often encountered in enginering practice. Available solutions are limited to special cases and are not easy to use. The aim of this work is to provide a simple tool for stress and strain calculations due to piecewise linear variation of ambient temperature. A variational approach is applied to obtain approximate temperature and stress distributions within the plate in a simple analytic form. Stress diagrams derived from the exact temperature distribution are used to assess the accuracy of the method. The method is finally used tomore » determine the magnitude of thermal stresses induced by thermal cycling. The results are shown to be in agreement with those of previous studies. 9 refs.« less
  • This study is designed to explore the two dimensional temperature maps of the atmospheric argon discharge consisting of pin-to-plane electrodes supplied by a high voltage DC source. After checking the stability of the micro discharge, the two dimensional image plane focused by a quartz lens was scanned by the fiber probe driven by a 3D Mobile Platform. The rotational and vibrational temperatures are calculated using nitrogen emissions collected by the high resolution spectrometer and high sensitive intensified charge coupled device. The rotational temperature varies from 1558.15 K to 2621.14 K and vibrational temperature varies from 3010.38 K to 3774.69 K, indicating a great temperaturemore » gradient due to small discharge size. The temperature maps show a lateral expansion and a sharp truncation in the radial direction. A double layers discharge is identified, where an arc discharge coats the glow discharge.« less