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EBEX The E and B EXperiment

EBEX The E and B EXperiment. Will Grainger Columbia University Moriond 2008. Collaboration. Columbia University Amber Miller Britt Reichborn- Kjennerud Will Grainger Michele Limon Harvard Matias Zaldarriaga IAS-Orsay Nicolas Ponthieu Imperial College Andrew Jaffe

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EBEX The E and B EXperiment

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  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

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