The EBEX Balloon-borne Experiment—Optics, Receiver, and Polarimetry ...

• Main Authors: Aboobaker, Asad M., Ade, Peter, Araujo, Derek, Aubin, François, Helson, Kyle, Collaboration, The EBEX, Et Al
• Format: Article in Journal/Newspaper
• Language: English
• Published: IOP 2018
• Subjects: Locke; Westbrook; Kyle; Antarc*; Antarctica
• Online Access: https://dx.doi.org/10.13016/m2hlej-jarh; https://mdsoar.org/handle/11603/24146

Authors: Asad M. Aboobaker,,, Peter Ade , Derek Araujo , François Aubin,, , Carlo Baccigalupi, , Chaoyun Bao , Daniel Chapman , Joy Didier,, , Matt Dobbs, , Christopher Geach , Will Grainger, Shaul Hanany , Kyle Helson,, , Seth Hillbrand , Johannes Hubmayr, Andrew Jaffe , Bradley Johnson , Terry Jones , Jeff Klein , Andrei Korotkov, Adrian Lee, Lorne Levinson , Michele Limon , Kevin MacDermid , Tomotake Matsumura,,, Amber D. Miller,,, Michael Milligan , Kate Raach , Britt Reichborn-Kjennerud , Ilan Sagiv , Giorgio Savini, Locke Spencer,,, Carole Tucker , Gregory S. Tucker , Benjamin Westbrook, Karl Young , and Kyle Zilic ... : The E and B Experiment (EBEX) was a long-duration balloon-borne cosmic microwave background (CMB) polarimeter that flew over Antarctica in 2012. We describe the experiment’s optical system, receiver, and polarimetric approach and report on their in-flight performance. EBEX had three frequency bands centered on 150, 250, and 410 GHz. To make efficient use of limited mass and space, we designed a 115 cm2 sr highthroughput optical system that had two ambient temperature mirrors and four antireflection-coated polyethylene lenses per focal plane. All frequency bands shared the same optical train. Polarimetry was achieved with a continuously rotating achromatic half-wave plate (AHWP) that was levitated with a superconducting magnetic bearing (SMB). This is the first use of an SMB in astrophysics. Rotation stability was 0.45% over a period of 10 hr, and angular position accuracy was 0°. 01. The measured modulation efficiency was above 90% for all bands. To our knowledge the 109% fractional bandwidth of the AHWP was ...