BICEP2 and Keck array: Upgrades and improved beam characterization

I. Buder, P. A.R. Ade, Z. Ahmed, R. W. Aikin, K. D. Alexander, M. Amiri, D. Barkats, S. J. Benton, C. A. Bischoff, J. J. Bock, J. A. Bonetti, J. A. Brevik, E. Bullock, B. Burger, B. P. Crill, G. Davis, C. D. Dowell, L. Duband, J. P. Filippini, S. FliescherS. R. Golwala, M. S. Gordon, M. Halpern, M. Hasselfield, S. R. Hildebrandt, G. C. Hilton, V. V. Hristov, H. Hui, K. D. Irwin, K. S. Karkare, J. P. Kaufman, B. G. Keating, S. Kefeli, S. A. Kernasovskiy, J. M. Kovac, C. L. Kuo, E. M. Leitch, M. Lueker, P. Mason, K. G. Megerian, C. B. Netterfield, H. T. Nguyen, R. O'Brient, R. W. Ogburn, A. Orlando, C. Pryke, C. D. Reintsema, S. Richter, R. Schwarz, C. D. Sheehy, Z. K. Staniszewski, R. V. Sudiwala, G. P. Teply, K. L. Thompson, J. E. Tolan, A. D. Turner, A. G. Vieregg, A. C. Weber, D. V. Wiebe, P. Wilson, C. L. Wong, K. W. Yoon

Research output: Chapter in Book/Report/Conference proceedingConference contribution

11 Citations (Scopus)

Abstract

Searching for evidence of inflation by measuring B-modes in the cosmic microwave background (CMB) polarization at degree angular scales remains one of the most compelling experimental challenges in cosmology. BICEP2 and the Keck Array are part of a program of experiments at the South Pole whose main goal is to achieve the sensitivity and systematic control necessary for measurements of the tensor-to-scalar ratio at σ(r) ∼0:01. Beam imperfections that are not sufficiently accounted for are a potential source of spurious polarization that could interfere with that goal. The strategy of BICEP2 and the Keck Array is to completely characterize their telescopes' polarized beam response with a combination of in-lab, pre-deployment, and on-site calibrations. We Sereport the status of these experiments, focusing on continued improved understanding of their beams. Far-field measurements of the BICEP2 beam with a chopped thermal source, combined with analysis improvements, show that the level of residual beam-induced systematic errors is acceptable for the goal of σ(r) ∼ 0:01 measurements. Beam measurements of the Keck Array side lobes helped identify a way to reduce optical loading with interior cold baffles, which we installed in late 2013. These baffles reduced total optical loading, leading to a ∼ 10% increase in mapping speed for the 2014 observing season. The sensitivity of the Keck Array continues to improve: for the 2013 season it was 9:5 μ 1/4K s noise equivalent temperature (NET). In 2014 we converted two of the 150-GHz cameras to 100 GHz for foreground separation capability. We have shown that the BICEP2 and the Keck Array telescope technology is sufficient for the goal of σ(r) ∼ 0:01 measurements. Furthermore, the program is continuing with BICEP3, a 100-GHz telescope with 2560 detectors.

Original languageEnglish (US)
Title of host publicationMillimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VII
EditorsJonas Zmuidzinas, Wayne S. Holland
PublisherSPIE
ISBN (Electronic)9780819496218
DOIs
StatePublished - Jan 1 2014
EventMillimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VII - Montreal, Canada
Duration: Jun 24 2014Jun 27 2014

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume9153
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X

Other

OtherMillimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VII
CountryCanada
CityMontreal
Period6/24/146/27/14

Fingerprint

Telescopes
Telescope
Baffle
baffles
telescopes
Cosmology
Polarization
Systematic errors
Systematic Error
sensitivity
Tensors
Imperfections
polarization
Poles
Far Field
systematic errors
lobes
Inflation
Microwave
Experiments

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

Cite this

Buder, I., Ade, P. A. R., Ahmed, Z., Aikin, R. W., Alexander, K. D., Amiri, M., ... Yoon, K. W. (2014). BICEP2 and Keck array: Upgrades and improved beam characterization. In J. Zmuidzinas, & W. S. Holland (Eds.), Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VII [915312] (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 9153). SPIE. https://doi.org/10.1117/12.2055713
Buder, I. ; Ade, P. A.R. ; Ahmed, Z. ; Aikin, R. W. ; Alexander, K. D. ; Amiri, M. ; Barkats, D. ; Benton, S. J. ; Bischoff, C. A. ; Bock, J. J. ; Bonetti, J. A. ; Brevik, J. A. ; Bullock, E. ; Burger, B. ; Crill, B. P. ; Davis, G. ; Dowell, C. D. ; Duband, L. ; Filippini, J. P. ; Fliescher, S. ; Golwala, S. R. ; Gordon, M. S. ; Halpern, M. ; Hasselfield, M. ; Hildebrandt, S. R. ; Hilton, G. C. ; Hristov, V. V. ; Hui, H. ; Irwin, K. D. ; Karkare, K. S. ; Kaufman, J. P. ; Keating, B. G. ; Kefeli, S. ; Kernasovskiy, S. A. ; Kovac, J. M. ; Kuo, C. L. ; Leitch, E. M. ; Lueker, M. ; Mason, P. ; Megerian, K. G. ; Netterfield, C. B. ; Nguyen, H. T. ; O'Brient, R. ; Ogburn, R. W. ; Orlando, A. ; Pryke, C. ; Reintsema, C. D. ; Richter, S. ; Schwarz, R. ; Sheehy, C. D. ; Staniszewski, Z. K. ; Sudiwala, R. V. ; Teply, G. P. ; Thompson, K. L. ; Tolan, J. E. ; Turner, A. D. ; Vieregg, A. G. ; Weber, A. C. ; Wiebe, D. V. ; Wilson, P. ; Wong, C. L. ; Yoon, K. W. / BICEP2 and Keck array : Upgrades and improved beam characterization. Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VII. editor / Jonas Zmuidzinas ; Wayne S. Holland. SPIE, 2014. (Proceedings of SPIE - The International Society for Optical Engineering).
@inproceedings{50cb27c4dcd84d3b8f653956631199c9,
title = "BICEP2 and Keck array: Upgrades and improved beam characterization",
abstract = "Searching for evidence of inflation by measuring B-modes in the cosmic microwave background (CMB) polarization at degree angular scales remains one of the most compelling experimental challenges in cosmology. BICEP2 and the Keck Array are part of a program of experiments at the South Pole whose main goal is to achieve the sensitivity and systematic control necessary for measurements of the tensor-to-scalar ratio at σ(r) ∼0:01. Beam imperfections that are not sufficiently accounted for are a potential source of spurious polarization that could interfere with that goal. The strategy of BICEP2 and the Keck Array is to completely characterize their telescopes' polarized beam response with a combination of in-lab, pre-deployment, and on-site calibrations. We Sereport the status of these experiments, focusing on continued improved understanding of their beams. Far-field measurements of the BICEP2 beam with a chopped thermal source, combined with analysis improvements, show that the level of residual beam-induced systematic errors is acceptable for the goal of σ(r) ∼ 0:01 measurements. Beam measurements of the Keck Array side lobes helped identify a way to reduce optical loading with interior cold baffles, which we installed in late 2013. These baffles reduced total optical loading, leading to a ∼ 10{\%} increase in mapping speed for the 2014 observing season. The sensitivity of the Keck Array continues to improve: for the 2013 season it was 9:5 μ 1/4K s noise equivalent temperature (NET). In 2014 we converted two of the 150-GHz cameras to 100 GHz for foreground separation capability. We have shown that the BICEP2 and the Keck Array telescope technology is sufficient for the goal of σ(r) ∼ 0:01 measurements. Furthermore, the program is continuing with BICEP3, a 100-GHz telescope with 2560 detectors.",
author = "I. Buder and Ade, {P. A.R.} and Z. Ahmed and Aikin, {R. W.} and Alexander, {K. D.} and M. Amiri and D. Barkats and Benton, {S. J.} and Bischoff, {C. A.} and Bock, {J. J.} and Bonetti, {J. A.} and Brevik, {J. A.} and E. Bullock and B. Burger and Crill, {B. P.} and G. Davis and Dowell, {C. D.} and L. Duband and Filippini, {J. P.} and S. Fliescher and Golwala, {S. R.} and Gordon, {M. S.} and M. Halpern and M. Hasselfield and Hildebrandt, {S. R.} and Hilton, {G. C.} and Hristov, {V. V.} and H. Hui and Irwin, {K. D.} and Karkare, {K. S.} and Kaufman, {J. P.} and Keating, {B. G.} and S. Kefeli and Kernasovskiy, {S. A.} and Kovac, {J. M.} and Kuo, {C. L.} and Leitch, {E. M.} and M. Lueker and P. Mason and Megerian, {K. G.} and Netterfield, {C. B.} and Nguyen, {H. T.} and R. O'Brient and Ogburn, {R. W.} and A. Orlando and C. Pryke and Reintsema, {C. D.} and S. Richter and R. Schwarz and Sheehy, {C. D.} and Staniszewski, {Z. K.} and Sudiwala, {R. V.} and Teply, {G. P.} and Thompson, {K. L.} and Tolan, {J. E.} and Turner, {A. D.} and Vieregg, {A. G.} and Weber, {A. C.} and Wiebe, {D. V.} and P. Wilson and Wong, {C. L.} and Yoon, {K. W.}",
year = "2014",
month = "1",
day = "1",
doi = "10.1117/12.2055713",
language = "English (US)",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
publisher = "SPIE",
editor = "Jonas Zmuidzinas and Holland, {Wayne S.}",
booktitle = "Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VII",
address = "United States",

}

Buder, I, Ade, PAR, Ahmed, Z, Aikin, RW, Alexander, KD, Amiri, M, Barkats, D, Benton, SJ, Bischoff, CA, Bock, JJ, Bonetti, JA, Brevik, JA, Bullock, E, Burger, B, Crill, BP, Davis, G, Dowell, CD, Duband, L, Filippini, JP, Fliescher, S, Golwala, SR, Gordon, MS, Halpern, M, Hasselfield, M, Hildebrandt, SR, Hilton, GC, Hristov, VV, Hui, H, Irwin, KD, Karkare, KS, Kaufman, JP, Keating, BG, Kefeli, S, Kernasovskiy, SA, Kovac, JM, Kuo, CL, Leitch, EM, Lueker, M, Mason, P, Megerian, KG, Netterfield, CB, Nguyen, HT, O'Brient, R, Ogburn, RW, Orlando, A, Pryke, C, Reintsema, CD, Richter, S, Schwarz, R, Sheehy, CD, Staniszewski, ZK, Sudiwala, RV, Teply, GP, Thompson, KL, Tolan, JE, Turner, AD, Vieregg, AG, Weber, AC, Wiebe, DV, Wilson, P, Wong, CL & Yoon, KW 2014, BICEP2 and Keck array: Upgrades and improved beam characterization. in J Zmuidzinas & WS Holland (eds), Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VII., 915312, Proceedings of SPIE - The International Society for Optical Engineering, vol. 9153, SPIE, Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VII, Montreal, Canada, 6/24/14. https://doi.org/10.1117/12.2055713

BICEP2 and Keck array : Upgrades and improved beam characterization. / Buder, I.; Ade, P. A.R.; Ahmed, Z.; Aikin, R. W.; Alexander, K. D.; Amiri, M.; Barkats, D.; Benton, S. J.; Bischoff, C. A.; Bock, J. J.; Bonetti, J. A.; Brevik, J. A.; Bullock, E.; Burger, B.; Crill, B. P.; Davis, G.; Dowell, C. D.; Duband, L.; Filippini, J. P.; Fliescher, S.; Golwala, S. R.; Gordon, M. S.; Halpern, M.; Hasselfield, M.; Hildebrandt, S. R.; Hilton, G. C.; Hristov, V. V.; Hui, H.; Irwin, K. D.; Karkare, K. S.; Kaufman, J. P.; Keating, B. G.; Kefeli, S.; Kernasovskiy, S. A.; Kovac, J. M.; Kuo, C. L.; Leitch, E. M.; Lueker, M.; Mason, P.; Megerian, K. G.; Netterfield, C. B.; Nguyen, H. T.; O'Brient, R.; Ogburn, R. W.; Orlando, A.; Pryke, C.; Reintsema, C. D.; Richter, S.; Schwarz, R.; Sheehy, C. D.; Staniszewski, Z. K.; Sudiwala, R. V.; Teply, G. P.; Thompson, K. L.; Tolan, J. E.; Turner, A. D.; Vieregg, A. G.; Weber, A. C.; Wiebe, D. V.; Wilson, P.; Wong, C. L.; Yoon, K. W.

Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VII. ed. / Jonas Zmuidzinas; Wayne S. Holland. SPIE, 2014. 915312 (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 9153).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

TY - GEN

T1 - BICEP2 and Keck array

T2 - Upgrades and improved beam characterization

AU - Buder, I.

AU - Ade, P. A.R.

AU - Ahmed, Z.

AU - Aikin, R. W.

AU - Alexander, K. D.

AU - Amiri, M.

AU - Barkats, D.

AU - Benton, S. J.

AU - Bischoff, C. A.

AU - Bock, J. J.

AU - Bonetti, J. A.

AU - Brevik, J. A.

AU - Bullock, E.

AU - Burger, B.

AU - Crill, B. P.

AU - Davis, G.

AU - Dowell, C. D.

AU - Duband, L.

AU - Filippini, J. P.

AU - Fliescher, S.

AU - Golwala, S. R.

AU - Gordon, M. S.

AU - Halpern, M.

AU - Hasselfield, M.

AU - Hildebrandt, S. R.

AU - Hilton, G. C.

AU - Hristov, V. V.

AU - Hui, H.

AU - Irwin, K. D.

AU - Karkare, K. S.

AU - Kaufman, J. P.

AU - Keating, B. G.

AU - Kefeli, S.

AU - Kernasovskiy, S. A.

AU - Kovac, J. M.

AU - Kuo, C. L.

AU - Leitch, E. M.

AU - Lueker, M.

AU - Mason, P.

AU - Megerian, K. G.

AU - Netterfield, C. B.

AU - Nguyen, H. T.

AU - O'Brient, R.

AU - Ogburn, R. W.

AU - Orlando, A.

AU - Pryke, C.

AU - Reintsema, C. D.

AU - Richter, S.

AU - Schwarz, R.

AU - Sheehy, C. D.

AU - Staniszewski, Z. K.

AU - Sudiwala, R. V.

AU - Teply, G. P.

AU - Thompson, K. L.

AU - Tolan, J. E.

AU - Turner, A. D.

AU - Vieregg, A. G.

AU - Weber, A. C.

AU - Wiebe, D. V.

AU - Wilson, P.

AU - Wong, C. L.

AU - Yoon, K. W.

PY - 2014/1/1

Y1 - 2014/1/1

N2 - Searching for evidence of inflation by measuring B-modes in the cosmic microwave background (CMB) polarization at degree angular scales remains one of the most compelling experimental challenges in cosmology. BICEP2 and the Keck Array are part of a program of experiments at the South Pole whose main goal is to achieve the sensitivity and systematic control necessary for measurements of the tensor-to-scalar ratio at σ(r) ∼0:01. Beam imperfections that are not sufficiently accounted for are a potential source of spurious polarization that could interfere with that goal. The strategy of BICEP2 and the Keck Array is to completely characterize their telescopes' polarized beam response with a combination of in-lab, pre-deployment, and on-site calibrations. We Sereport the status of these experiments, focusing on continued improved understanding of their beams. Far-field measurements of the BICEP2 beam with a chopped thermal source, combined with analysis improvements, show that the level of residual beam-induced systematic errors is acceptable for the goal of σ(r) ∼ 0:01 measurements. Beam measurements of the Keck Array side lobes helped identify a way to reduce optical loading with interior cold baffles, which we installed in late 2013. These baffles reduced total optical loading, leading to a ∼ 10% increase in mapping speed for the 2014 observing season. The sensitivity of the Keck Array continues to improve: for the 2013 season it was 9:5 μ 1/4K s noise equivalent temperature (NET). In 2014 we converted two of the 150-GHz cameras to 100 GHz for foreground separation capability. We have shown that the BICEP2 and the Keck Array telescope technology is sufficient for the goal of σ(r) ∼ 0:01 measurements. Furthermore, the program is continuing with BICEP3, a 100-GHz telescope with 2560 detectors.

AB - Searching for evidence of inflation by measuring B-modes in the cosmic microwave background (CMB) polarization at degree angular scales remains one of the most compelling experimental challenges in cosmology. BICEP2 and the Keck Array are part of a program of experiments at the South Pole whose main goal is to achieve the sensitivity and systematic control necessary for measurements of the tensor-to-scalar ratio at σ(r) ∼0:01. Beam imperfections that are not sufficiently accounted for are a potential source of spurious polarization that could interfere with that goal. The strategy of BICEP2 and the Keck Array is to completely characterize their telescopes' polarized beam response with a combination of in-lab, pre-deployment, and on-site calibrations. We Sereport the status of these experiments, focusing on continued improved understanding of their beams. Far-field measurements of the BICEP2 beam with a chopped thermal source, combined with analysis improvements, show that the level of residual beam-induced systematic errors is acceptable for the goal of σ(r) ∼ 0:01 measurements. Beam measurements of the Keck Array side lobes helped identify a way to reduce optical loading with interior cold baffles, which we installed in late 2013. These baffles reduced total optical loading, leading to a ∼ 10% increase in mapping speed for the 2014 observing season. The sensitivity of the Keck Array continues to improve: for the 2013 season it was 9:5 μ 1/4K s noise equivalent temperature (NET). In 2014 we converted two of the 150-GHz cameras to 100 GHz for foreground separation capability. We have shown that the BICEP2 and the Keck Array telescope technology is sufficient for the goal of σ(r) ∼ 0:01 measurements. Furthermore, the program is continuing with BICEP3, a 100-GHz telescope with 2560 detectors.

UR - http://www.scopus.com/inward/record.url?scp=84922901072&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84922901072&partnerID=8YFLogxK

U2 - 10.1117/12.2055713

DO - 10.1117/12.2055713

M3 - Conference contribution

AN - SCOPUS:84922901072

T3 - Proceedings of SPIE - The International Society for Optical Engineering

BT - Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VII

A2 - Zmuidzinas, Jonas

A2 - Holland, Wayne S.

PB - SPIE

ER -

Buder I, Ade PAR, Ahmed Z, Aikin RW, Alexander KD, Amiri M et al. BICEP2 and Keck array: Upgrades and improved beam characterization. In Zmuidzinas J, Holland WS, editors, Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VII. SPIE. 2014. 915312. (Proceedings of SPIE - The International Society for Optical Engineering). https://doi.org/10.1117/12.2055713