Abstract
We present the design and measured performance of the superconducting magnetic bearing (SMB) that was used successfully as the rotation mechanism in the half-wave plate Polarimeter of the E and B Experiment (EBEX) during its North American test flight. EBEX is a NASA-supported balloon-borne experiment that is designed to measure the polarization of the cosmic microwave background. In this implementation the half-wave plate is mounted to the rotor of an SMB that is operating at a sink temperature of 4 K. We demonstrate robust, remote operation on a balloon-borne payload, with angular encoding accuracy of 0.01°. We find rotational speed variations to be 0.2% RMS. We measure vibrational modes and find them to be consistent with a simple SMB model. We search for but do not find magnetic field interference in the detectors and readout. We set an upper limit of 3% of the receiver noise level after 5 minutes of integration on such interference. At 2 Hz rotation we measure a power dissipation of 56 mW. If this power dissipation is reduced, such an SMB implementation is a candidate for low-noise space applications because of the absence of stick-slip friction and low wear.
Original language | English (US) |
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Title of host publication | Cryogenic Optical Systems and Instruments XIII |
Publisher | SPIE |
ISBN (Print) | 9780819487605 |
DOIs | |
State | Published - 2011 |
Event | Cryogenic Optical Systems and Instruments XIII - San Diego, CA, United States Duration: Aug 24 2011 → Aug 25 2011 |
Publication series
Name | Proceedings of SPIE - The International Society for Optical Engineering |
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Volume | 8150 |
ISSN (Print) | 0277-786X |
Conference
Conference | Cryogenic Optical Systems and Instruments XIII |
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Country/Territory | United States |
City | San Diego, CA |
Period | 8/24/11 → 8/25/11 |