The EBEX Balloon-borne Experiment-Optics, Receiver, and Polarimetry
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...
Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
IOP PUBLISHING LTD
2018
|
Subjects: | |
Online Access: | https://discovery.ucl.ac.uk/id/eprint/10064677/1/The_EBEX_Collaboration_2018_ApJS_239_7.pdf https://discovery.ucl.ac.uk/id/eprint/10064677/ |
id |
ftucl:oai:eprints.ucl.ac.uk.OAI2:10064677 |
---|---|
record_format |
openpolar |
spelling |
ftucl:oai:eprints.ucl.ac.uk.OAI2:10064677 2023-12-24T10:11:20+01:00 The EBEX Balloon-borne Experiment-Optics, Receiver, and Polarimetry Aboobaker, AM Ade, P Araujo, D Aubin, F Baccigalupi, C Bao, C Chapman, D Didier, J Dobbs, M Geach, C Grainger, W Hanany, S Helson, K Hillbrand, S Hubmayr, J Jaffe, A Johnson, B Jones, T Klein, J Korotkov, A Lee, A Levinson, L Limon, M MacDermid, K Matsumura, T Miller, AD Milligan, M Raach, K Reichborn-Kjennerud, B Sagiv, I Savini, G Spencer, L Tucker, C Tucker, GS Westbrook, B Young, K Zilic, K 2018-11-06 text https://discovery.ucl.ac.uk/id/eprint/10064677/1/The_EBEX_Collaboration_2018_ApJS_239_7.pdf https://discovery.ucl.ac.uk/id/eprint/10064677/ eng eng IOP PUBLISHING LTD https://discovery.ucl.ac.uk/id/eprint/10064677/1/The_EBEX_Collaboration_2018_ApJS_239_7.pdf https://discovery.ucl.ac.uk/id/eprint/10064677/ open The Astrophysical Journal Supplement Series , 239 (1) , Article 7. (2018) Article 2018 ftucl 2023-11-27T13:07:26Z 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 the broadest implemented to date. The receiver, composed of one lens and the AHWP at a temperature of 4 K, the polarizing grid and other lenses at 1 K, and the two focal planes at 0.25 K, performed according to specifications, giving focal plane temperature stability with a fluctuation power spectrum that had a 1/f knee at 2 mHz. EBEX was the first balloon-borne instrument to implement technologies characteristic of modern CMB polarimeters, including high-throughput optical systems, and large arrays of transition edge sensor bolometric detectors with multiplexed readouts. Article in Journal/Newspaper Antarc* Antarctica University College London: UCL Discovery |
institution |
Open Polar |
collection |
University College London: UCL Discovery |
op_collection_id |
ftucl |
language |
English |
description |
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 the broadest implemented to date. The receiver, composed of one lens and the AHWP at a temperature of 4 K, the polarizing grid and other lenses at 1 K, and the two focal planes at 0.25 K, performed according to specifications, giving focal plane temperature stability with a fluctuation power spectrum that had a 1/f knee at 2 mHz. EBEX was the first balloon-borne instrument to implement technologies characteristic of modern CMB polarimeters, including high-throughput optical systems, and large arrays of transition edge sensor bolometric detectors with multiplexed readouts. |
format |
Article in Journal/Newspaper |
author |
Aboobaker, AM Ade, P Araujo, D Aubin, F Baccigalupi, C Bao, C Chapman, D Didier, J Dobbs, M Geach, C Grainger, W Hanany, S Helson, K Hillbrand, S Hubmayr, J Jaffe, A Johnson, B Jones, T Klein, J Korotkov, A Lee, A Levinson, L Limon, M MacDermid, K Matsumura, T Miller, AD Milligan, M Raach, K Reichborn-Kjennerud, B Sagiv, I Savini, G Spencer, L Tucker, C Tucker, GS Westbrook, B Young, K Zilic, K |
spellingShingle |
Aboobaker, AM Ade, P Araujo, D Aubin, F Baccigalupi, C Bao, C Chapman, D Didier, J Dobbs, M Geach, C Grainger, W Hanany, S Helson, K Hillbrand, S Hubmayr, J Jaffe, A Johnson, B Jones, T Klein, J Korotkov, A Lee, A Levinson, L Limon, M MacDermid, K Matsumura, T Miller, AD Milligan, M Raach, K Reichborn-Kjennerud, B Sagiv, I Savini, G Spencer, L Tucker, C Tucker, GS Westbrook, B Young, K Zilic, K The EBEX Balloon-borne Experiment-Optics, Receiver, and Polarimetry |
author_facet |
Aboobaker, AM Ade, P Araujo, D Aubin, F Baccigalupi, C Bao, C Chapman, D Didier, J Dobbs, M Geach, C Grainger, W Hanany, S Helson, K Hillbrand, S Hubmayr, J Jaffe, A Johnson, B Jones, T Klein, J Korotkov, A Lee, A Levinson, L Limon, M MacDermid, K Matsumura, T Miller, AD Milligan, M Raach, K Reichborn-Kjennerud, B Sagiv, I Savini, G Spencer, L Tucker, C Tucker, GS Westbrook, B Young, K Zilic, K |
author_sort |
Aboobaker, AM |
title |
The EBEX Balloon-borne Experiment-Optics, Receiver, and Polarimetry |
title_short |
The EBEX Balloon-borne Experiment-Optics, Receiver, and Polarimetry |
title_full |
The EBEX Balloon-borne Experiment-Optics, Receiver, and Polarimetry |
title_fullStr |
The EBEX Balloon-borne Experiment-Optics, Receiver, and Polarimetry |
title_full_unstemmed |
The EBEX Balloon-borne Experiment-Optics, Receiver, and Polarimetry |
title_sort |
ebex balloon-borne experiment-optics, receiver, and polarimetry |
publisher |
IOP PUBLISHING LTD |
publishDate |
2018 |
url |
https://discovery.ucl.ac.uk/id/eprint/10064677/1/The_EBEX_Collaboration_2018_ApJS_239_7.pdf https://discovery.ucl.ac.uk/id/eprint/10064677/ |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_source |
The Astrophysical Journal Supplement Series , 239 (1) , Article 7. (2018) |
op_relation |
https://discovery.ucl.ac.uk/id/eprint/10064677/1/The_EBEX_Collaboration_2018_ApJS_239_7.pdf https://discovery.ucl.ac.uk/id/eprint/10064677/ |
op_rights |
open |
_version_ |
1786163462678773760 |