1 / 16

EBEX The E and B EXperiment

The EBEX (E and B Experiment) aims to explore cosmic microwave background (CMB) polarization through a long-duration balloon-borne mission. Utilizing 1476 bolometric transition edge sensors (TES) over three frequency bands (150, 250, 410 GHz), the experiment targets detection of inflationary B-mode signals and lensing B-modes with high precision. By implementing advanced polarimetric techniques, EBEX seeks to measure and subtract polarized dust emissions effectively. The results will provide crucial insights into the early universe and the properties of polarized foregrounds.

keefer
Télécharger la présentation

EBEX The E and B EXperiment

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. EBEXThe E and B EXperiment Will Grainger Columbia University Moriond 2008

  2. Collaboration Columbia University Amber Miller Britt Reichborn- Kjennerud Will Grainger Michele Limon Harvard Matias Zaldarriaga IAS-Orsay Nicolas Ponthieu Imperial College Andrew Jaffe Lawrence Berkeley National Lab Julian Borrill McGill University Francois Aubin Eric Bisonnette Matt Dobbs Kevin MacDermid Oxford Brad Johnson SISSA-Trieste Carlo Baccigalupi Sam Leach Federico Stivoli University of California/Berkeley Adrian Lee Xiaofan Meng Huan Tran University of California/San Diego Tom Renbarger University of Minnesota/Twin Cities Asad Aboobaker Shaul Hanany (PI) Clay Hogen-Chin Hannes Hubmayr Terry Jones Jeff Klein Michael Milligan Dan Polsgrove Ilan Sagiv Kyle Zilic Weizmann Institute of Science Lorne Levinson APC – Paris Radek Stompor Brown University Andrei Korotkov John Macaluso Greg Tucker Yuri Vinokurov CalTech Tomotake Matsumura Cardiff Peter Ade Enzo Pascale

  3. EBEX in a Nutshell • CMB Polarization Experiment • Long duration, balloon borne • Use 1476 bolometric TES • 3 Frequency bands: 150, 250, 410 GHz • Resolution: 8’ at all frequencies • Polarimetry with half wave plate • BLAST (+ BOOM, MAXIMA) balloon technologies

  4. Science Goals • Detect (or set upper bound) in inflationary B-mode • T/S < 0.02 at 2σ (excluding systematic and foreground subtraction uncertainty) • Detect lensing B-mode • 5% error on amplitude of lensing power spectrum • Measure E-E power spectrum • Determine properties of polarized dust EBEX, 14 days

  5. Dust Determination and Subtraction • Simulate CMB B, dust, noise • Reconstruct dust + CMB maps (using the parametric separation technique) • Less than 1/3  increase in error on recovered CMB over binned cosmic variance and instrument noise due to foreground subtraction for l=20 to 900. • Reconstruction of dust spectral index within 5% • Blue= INPUT dust model • Red= INPUT CMB + instrument noise + sample variance • Black dust = data + errors of reconstruction • Black CMB = variance of 10 simulations • No systematic uncertainties

  6. Design 250 cm

  7. Cryostat and Optics • Reflecting Gregorian Dragone telescope • Control of sidelobes: Cold aperture stop Stop + • Polarimetric systematics: Half Wave Plate • Efficiency: Detection of two orthogonal states

  8. 36 cm Focal Planes Single TES 738 element array 250 150 410 2.1 mm 3 mm Strehl>0.85 at 250 GHz Meng, Lee, UCB • Total of 1476 detectors • Maintained at 0.27 K • 3 frequency bands/focal plane • G = 10 pWatt/K • NEP = 1.1e-17 (150 GHz) • NEQ = 136 μK*rt(sec) (150 GHz) • msec,

  9. Detector Readouts • SQUID arrays (NIST) • Digital Frequency Domain Multiplexing (McGill) FPGA Synthesizes Comb; Controls SQUIDs; Demodulates • LDB: 495 Watt for x12; 406 Watt for x16

  10. Half Wave Plate Polarimetry • 5 stack achromatic HWP • 0.98 efficiency for 120< ν < 420 Ghz • 6 Hz rotation • < 10% attenuation from 3 msec time constant • Driven by motor outside cryostat via Kevlar belt • Supported on superconducting magnetic bearing

  11. EBEX Scan • Scan is: • Constant elevation for 4 repeats, one Q,U per 1/3 beam, (0.7 deg/sec). • Step in elevation, and repeat; 102 times. • Repeat that 6 hour block on same patch of sky for 14 days. • Multiple visitations per pixel from various angles (i.e. crosslinking) on various timescales. • Relatively uniform coverage • Up to 10^8 samples/beam 17 deg p-p / 0.7 deg/sec x4 . . . . . 6 hours 102 steps All 150 GHz detectors, 14 Day

  12. Gondola + Pointing Cable Suspension (a-la BLAST) Pointing System (BLAST, MAXIMA, Boom) Gondola integrated at Columbia U. Pointing tests ongoing

  13. EBEX Summary + Schedule • 14 day flight • 420 deg2 • ~24,000 8’ pixels • Low dust contrast (4mK rms) • 796, 398, 282 TES detectors at 150, 250, 410 GHz • 0.7 mK/8’ pixel - Q/U; • 0.5 mK/8’ pixel – T • Currently integrating • detectors into cryostat in UMN • Pointing sensors onto gondola in CU • North American flight: Autumn 2008 • Long Duration (Antarctic) flight: Austral Summer 2009

  14. Nothing to see here…

  15. Optics • Reflecting Gregorian Dragone telescope • Control of sidelobes: Cold aperture stop • wide range of ls probed. Stop + • Polarimetric systematics: Half Wave Plate • Efficiency: Detection of two orthogonal states

  16. Design Blue – Synchrotron Pink – Dust Minimize synchrotron by going to high frequency, then only one foreground to deal with. 250 cm

More Related