The POLARBEAR Experiment. Haruki Nishino for the POLARBEAR Collaboration (University of California, 47th Rencontres 1 de Moriond

Transcription

1 The POLARBEAR Experiment Haruki Nishino for the POLARBEAR Collaboration (University of California, 47th Rencontres 1 de Moriond

2 Outline POLARBEAR scientific goals POLARBEAR Instruments Deployment at Chile Upgrade Plan Engineering Run at East California 2

3 University of California, Berkeley Kam Arnold Daniel Flanigan William Holzapfel Jacob Howard Zigmund Kermish Adrian Lee Marius Lungu Mike Myers Haruki Nishino Erin Quealy Christian Reichardt Paul Richards Chase Shimmin Bryan Steinbach Aritoki Suzuki Oliver Zahn POLARBEAR Collaboration Lawrence Berkeley National Lab Julian Borrill Theodore Kisner Eric Linder Mike Sholl Helmuth Spieler University of California, San Diego Darcy Barron David Boettger Brian Keating George Fuller Frederick Matsuda Nathan Miller Stephanie Moyerman Hans Paar Ian Schanning Meir Shimon Praween Siritanasak Nathan Stebor University of Colorado, Boulder Aubra Anthony Nils Halverson Austin College Peter Hyland Dalhouse University Scott Chapman Colin Ross KEK Yuji Chinone Masaya Hasegawa Kaori Hattori Masashi Hazumi Tomotake Matsumura Hideki Morii Akie Shimizu Takayuki Tomaru Cardiff University Peter Ade Will Grainger Carole Tucker Imperial College Andrew Jaffe McGill University Matt Dobbs Laboratoire Astroparticule & Cosmologie Josquin Errard Giulio Fabbian Maude LeJeune Radek Stompor POLARBEAR is Funded by - NSF AST MEXT KAKENHI International Collaboration from 5 countries, 11 institutes 3

4 POLARBEAR Science Goals POLARBEAR will measure CMB polarization with unprecedented high precision Prove the epoch of inflationary cosmology by detecting B-mode polarization pattern generated by primordial gravitational wave sensitivity for scalar to tensor ratio r=0.025 (95%CL) Weak lensing by large scale structure also generates B-modes at smaller angular scales POLARBEAR expected sensitivity (3 seasons) E-mode Sensitive to sum of neutrino mass: 75 mev (68%C.L.) (combined with Planck) Inflationary B-mode 4 Weak-lensing B-mode

5 Huan Tran Telescope (HTT) 3.5m primary mirror: 2.5m high accuracy monolithic panel + guard ring panel off-axis Gregorian Dragone design receiver secondary mirror Beam Size: 3.5 at 150GHz sensitive to weak lensing B-mode 5 cold stepped-rotating HWP

6 Antenna-coupled TES Bolometer Arrays 91 pixels (182 bolometers) per wafer under AR-coated lenslets TES bolometer Microstrip Filter (150GHz) Total: 7 wafers 637 pixels (1274 bolos) Expected Array Sensitivity: ~13 µk s 6 Dual-Polarization Slot Antenna

7 Results from Engineering Run in East California End-to-End test of entire system Telescope, bolometer, readout, cryogenics, data acquisition, Quicklook software, etc. During summer 2010 at Cedar Flat, California, the CARMA (Combined Array for Research in Millimeterwave Astronomy) site at 2200m altitude. Three of seven wafers were installed. 7 HTT at the CARMA site, 2010

8 Beam Map (Jupiter) Made Beam Maps using Jupiter beam size: 3.8 arcmin (FWHM) consistent beam with optics simulation Effect estimated sys. error requirem ent for r=0.025 Differential Beam Size 0.4% 1.5% Differential Pointing Differential Ellipticity 0.5% 2.9% 8 Estimated differential beam systematics Systematic beam difference between two polarization detectors makes fake B-mode signal. Beam systematics are satisfactorily low for r~0.025 sensitivity. N. J. Miller et al., PRD 79, (2009) N. J. Miller et al., PRD 79, (2009) M. Shimon et al., PRD 77, (2008)

9 to re. The n the with mea- puter ssian nutes have omes nd is s not or as consistent between daytime and night. Noise Property Sum and difference of a pair bolometers calibrator test signal primordial gravitational wave 0.1Hz 1Hz Frequency weak lensing 10Hz 100Hz Figure 8: mode Sum and bolometers in a common noisedifference reduction of in the pair difference Large pixel demonstrating 1/f noise ~ 100mHz common-mode removal of atmo ts, it Achieved spheric expected fluctuations. knee at 100 NET atthe the California site mhz in the olardifference data is likely an9 upper limit due to length

10 Tau A observation Tau A is a supernova remnant SN1054 a.k.a. the Crab nebula. A bright polarized source from synchrotron emission of electrons in the nebula. A good calibration source for polarization angle calibration. 10 P= (Q 2 +U 2 ) 10 DEC (arcmin) mk Validated polarization sensitivity of the whole observation system of POLARBEAR Agrees with J. Aumont et al. (2010) (IRAM 30m telescope at 90GHz) RA (arcmin) 0 10

11 Deployment at Atacama Desert in Chile 11

12 Telescope/Site Deployment Site deployment was started in mid-september Telescope Assembly 12

13 Installing Focal Plane/Receiver Focal Plane/Receiver Assembly Hoisting Receiver up on Telescope 13

14 Ready for Observation The design of the bolometer saturation power is confirmed to be suitable to the Chilean sky. The cryogenic performance of the receiver is excellent. The bolometer readout including related software is working well. The telescope works well. HTT at the James Ax Observatory 14

15 First Light Jupiter Achieved first-light on January 10th, 2012! Four months after we started pouring concrete 15

16 Beam Map with Chile Data 3.5 arc-min Gaussian beam coadded all pixels More detailed study is in progress. 16

17 Observation Plan for CMB Dust Map and Observation Patches of Various Experiments POLARBEAR patches Three 15x15deg patches 700 deg 2 deep observation Selected lowest dust region Overlapping with QUIET, EBEX, Herschel, Planck Foreground contamination can be constrained by Planck ( GHz) for dust QUIET (40+90GHz) for synchrotron cross-correlation with IR galaxy count observation 17

18 POLARBEAR-2!"#$%&'&()&*$+*,-./0/!"#$%$&'$("%()*+,-,".-+"/*01,$2"*1",3$"%-((&$(4" Ghz Pol.A 90Ghz Pol.B 150Ghz Pol.A 150Ghz Pol.B Efficiency Figure 14: The polarbear-1 array was built using 10-cmincreased number of detectors wafers. We have migrated (7,588 our process diameter to 15-cm-diameter wafers for polarbear-2 as bolometers) with larger multiplexed shown in Fig. 11. Each wafer has mm SQUID readout other alternate. Upgrade of POLARBEAR Array Configuration dichroic detector ( GHz) 㻕 diameter pixels with a total of 1,084 bolometers on each wafer. Seven wafers make up thewith full Better sensitivity for r and neutrino mass polarbear-2 array with 7,588 total bolometers. a combination of deep/shallow observations The sub-arrays will be built into modules Frequency [GHz] similar to the polarbear-1 modules shown in 18 Measured spectral response of 90/150 Fig. 11. The cold components of the bolome-

19 Summary POLARBEAR is a ground-based experiment in the Atacama desert of Chile, built to detect CMB B- mode polarization with a1,274-tes bolometer array. Engineering run at California shows the entire system of POLARBEAR works well. POLARBEAR started the deployment in Chile in September 2011 and achieved first-light in January We will start science observation shortly. We already have started developments for the next upgrade of POLARBEAR Updates will be reported in

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21 Experimental Overview Detector Sensitivity Readout Observation Frequency Telescope Site Polarization Modulation Sky Coverage Antenna coupled Superconducting TES Bolometer 1274 bolos, 637 pairs ~0.5mK sqrt(sec)/bolometer Frequency Domain Multiplexed (8ch) Readout w/ SQUID 150GHz Off-axis Gregorian Dragone Atacama Desert, Chile (Altitude: ~5200m) Half-wave Plate and Sky Rotation 700deg 2 deep observation 21

22 POLARBEAR Receiver Pulse Tube Cooler He Sorption Refrigerator Cold Reimaging Optics IR blocking filters SQUID Focal Plane, bolometer stage: 0.26K Rotating HWP 22

23 POLARBEAR site (before deployment) ALMA Telescope will be here POLARBEAR site (~5200m altitude) on the Atacama plateau, Chile, in Summer