LiteBIRD Lite (Light) Satellite for the Studies of B-mode Polarization and Inflation from Cosmic Background Radiation Detection Progress with LiteBIRD Masashi Hazumi (KEK/Kavli IPMU/SOKENDAI/ISAS JAXA) for the LiteBIRD working group 1 LiteBIRD JAXA Osaka U. Kavli IPMU Kansei U. Tsukuba APC Paris T. Dotani S. Kuromiya K. Hattori Gakuin U. M. Nagai R. Stompor H. Fuke M. Nakajima N. Katayama S. Matsuura H. Imada S. Takakura Y. Sakurai TIT Cardiff U. I. Kawano K. Takano H. Sugai Kitazato U. S. Matsuoka G. Pisano UC Berkeley / H. Matsuhara T. Kawasaki R. Chendra LBNL T. Matsumura Osaka Pref. U. KEK Paris ILP D. Barron K. Mitsuda M. Inoue M. Hazumi Konan U. U. Tokyo J. Errard J. Borrill T. Nishibori K. Kimura (PI) I. Ohta S. Sekiguchi Y. Chinone K. Nishijo H. Ogawa M. Hasegawa T. Shimizu CU Boulder A. Cukierman A. Noda N. Okada N. Kimura NAOJ S. Shu N. Halverson T. de Haan A. Okamoto K. Kohri A. Dominjon N. Tomita N. Goeckner-wald S. Sakai Okayama U. M. Maki T. Hasebe McGill U. P. Harvey Y. Sato T. Funaki Y. Minami J. Inatani Tohoku U. M. Dobbs C. Hill K. Shinozaki N. Hidehira T. Nagasaki K. Karatsu M. Hattori W. Holzapfel H. Sugita H. Ishino R. Nagata S. Kashima MPA Y. Hori Y. Takei A. Kibayashi H. Nishino T. Noguchi Nagoya U. E. Komatsu O. Jeong S. Utsunomiya Y. Kida S. Oguri Y. Sekimoto K. Ichiki NIST R. Keskitalo T. Wada K. Komatsu T. Okamura M. Sekine T. Kisner G. Hilton R. Yamamoto S. Uozumi N. Sato Yokohama A. Kusaka J. Hubmayr N. Yamasaki Y. Yamada J. Suzuki Saitama U. Natl. U. A. Lee(US PI) T. Yoshida T. Suzuki M. Naruse T. Fujino Stanford U. E. Linder K. Yotsumoto NIFS O. Tajima F. Irie P. Richards S. Cho S. Takada T. Tomaru NICT H. Kanai U. Seljak K. Irwin M. Yoshida Y. Uzawa S. Nakamura B. Sherwin S. Kernasovskiy T. Yamashita A. Suzuki C.-L. Kuo LiteBIRD working group SOKENDAI P. Turin D. Li Y. Akiba RIKEN B. Westbrook Y. Inoue S. Mima T. Namikawa JAXA engineers CMB N. Whitehorn H. Ishitsuka C. Otani W. Ogburn X-ray experimenters Y. Segawa astrophysicists U. Wisconsin UC San Diego S. Takatori T. Elleot K. Arnold D. Tanabe B. Keating H. Watanabe G. Rebeiz Super-conducting IR astronomers detector developers 138 members, international and interdisciplinary (as of May 1, 2016) 2 LiteBIRD Special importance of primordial CMB B-mode • Direct evidence for cosmic inflation • GUT-scale physics V: Inflaton potential r: tensor-to-scalar ratio proportional to the B-mode power • Arguably the first observation of quantum fluctuation of space-time ! • Observational tests of quantum gravity ! 3 LiteBIRD (Non-cosmic) Background • 2012: New category “missions for fundamental physics authorized by Steering Committee for Space Science (SCSS) of Japan • 2013: “ISAS/JAXA Framework toward Roadmap for Space Science and Exploration” lists “tests of cosmic inflation with the CMB B-mode” as a top-priority scientific objective. • 2014 Dec.: US proposal for LiteBIRD NASA Mission of Opportunity • 2015 Feb.: LiteBIRD ISAS/JAXA mission definition review Both proposals in Japan and US successfully passed the initial selection ! 4 LiteBIRD JAXA • Main mission • Cost cap $300M (same as ASTRO-H/Hitomi) • Will soon start conceptual design phase (Phase A1) Seeking for European partnership ! (dedicated talk on international collaboration tomorrow) NASA • Sub-K system as a package, incl. focal plane detectors and Sub-K coolers • Cost cap $65M • in Phase A now 5 LiteBIRD International collaboration • International collaboration essential. –LiteBIRD Joint Study Groups w/ external collaborators have been formed. • Talk on “Japanese plans w.r.t. international collaboration” tomorrow afternoon 6 LiteBIRD Space science and exploration at ISAS/JAXA K. Mitsuda ( ) ~300M$ cost cap ( ) Hitomi MMX Each project passed the mission definition review (MDR). 7 LiteBIRD Full success of LiteBIRD • s(r) < 1 × 10-3 (for r=0) • All sky survey (for 2 ≤ ≤ 200) Remarks 1. s(r) is the total uncertainty on the r measurement that includes the following uncertainties* • statistical uncertainties • instrumental systematic uncertainties • uncertainties due to residual foregrounds • uncertainties due to lensing B-mode • cosmic variance (for r > 0) • observer bias 2. The above be achieved without delensing. * We also use an expression dr = s(r=0), which has no cosmic variance. 8 B-mode power spectrum measurements LiteBIRD Figure by Yuji Chinone 9 B-mode power spectrum measurements LiteBIRD LiteBIRD Figure by Yuji Chinone 10 LiteBIRD s(r) < 0.001 is a well-motivated target ! • Many models predict r > 0.01 >10sigma discovery if s(r) < 0.001 • Less model-dependent prediction – Focus on the simplest models based on Occam’s razor principle. – Single field models that satisfy slow-roll conditions give Lyth relation N: e-folding mpl: reduced Planck mass – Thus, large-field variation (Df > mpl), which is well-motivated phenomenologically, leads to r > 0.002. • Model-dependent exercises come to the same conclusion (w/ very small exceptions). – Detection of r > 0.002 establishes large-field variation (Lyth bound). • Significant impact on superstring theory that faces difficulty in dealing with Df > mpl – Ruling out large-field variation is also a significant contribution to cosmology and fundamental physics. s(r) < 0.001 is needed to rule out large field models that satisfy the Lyth relation with >95%C.L. 11 LiteBIRD If evidence is found before launch • r is fairly large Comprehensive studies by LiteBIRD ! • Much more precise measurement of r from LiteBIRD will play a vital role in identifying the correct inflationary model. • LiteBIRD will measure the B-mode power spectrum w/ high significance for each bump if r>0.01. – Deeper level of fundamental physics s(r) < 0.001 for 2 ≤ l ≤ 200 is what we need to achieve in any case to set the future course of cosmology No-Lose Theorem of LiteBIRD 12 LiteBIRD Basic Strategy Powerful Duo X Focused mission Telescope arrays s(r)<0.001 on ground 2 ≤ l ≤ 200 30 ≤ l ≤ 3000~10000 e.g. CMB-S4 w/ many byproducts Improving s(r) by delensing with other observations is defined as “extra success” in LiteBIRD Mission Definition. 13 LiteBIRD Extra success Improve s(r) with external observations Topic Method Example Delensing Large CMB CMB-S4 data telescope array Namikawa and Nagata, JCAP 1409 (2014) 009 Cosmic infrared Herschel data background Sherwin and Schmittfull, Phys. Rev. D 92, 043005 (2015) Radio continuum SKA data survey Namikawa, Yamauchi, Sherwin, Nagata, Phys. Rev. D 93, 043527 (2016) Foreground Lower frequency C-BASS upgrade removal survey • Delensing improvement to s(r) can be factor ~2 or more. • Need to make sure systematic uncertainties are under control. 14 LiteBIRD Phase-A baseline design LiteBIRD • Mission module benefits from heritages of other missions (e.g. ASTRO-H) and ground-based experiments (e.g. POLARBEAR). Continuously-rotating • Bus module based on high TRL components half wave plate (HWP) Slip-ring technology Line of sight 0.1rpm FOV 10 x 20 deg. used for Shizuku spin rate 30 deg. Small refractive Multi-chroic HFT system TES focal plane detectors HFT Bus module Cryogenics JT/ST and ADR Crossed LFT (ASTRO-H heritage) Dragone LFT mirrors Cold mission module Fit in H2 1.8m envelope 15 LiteBIRD Launch Vehicle H3 • First test launch in 2020 • ½ cost w/ same capability (comparison w/ H-II B) 16 Orbit and scan LiteBIRD strategy L2 halo orbit Precession angle a = 0.1rpm 65° Sun 90 min. (~ 1 day as an option) Spin angle b = 30° Anti-sun direction 17 LiteBIRD Main specifications (Phase-A baseline design) Item Specification Orbit L2 halo orbit Launch year (vehicle) 2024-2025 (H3 or H2A) Observation (time) All-sky CMB survey (3 years) Mass 2.2 t Power 2.5 kW Mission instruments • Superconducting detector arrays • Continuously-rotating half-wave plate (HWP) • Crossed-Dragone mirrors (+ small refractive telescope) • 0.1K cooling system (ST/JT/ADR) Frequencies (# of bands) 40 – 400 GHz (15 bands) Data size 4 GB/day Sensitivity 3 mKarcmin (3 years) with margin Angular resolution 0.5deg @ 100 GHz (FWHM) 18 LiteBIRD Design of low frequency telescope (LFT) Strehl ratio @150GHz over wide (10x20deg2) FOV on LFT Crossed Dragone CMB Spin 1.00 for compact axis (Lines show configuration rotation of polarization angle) with wide FOV. 0.96 ~5K Cooled 0.92 Aperture <10K Sidelobe features 100mK Focal Plane Telecentric <10K 400mm F/#=3.5 w/o aperture Very good overall performance ! w/ aperture + hood 19 LiteBIRD Experimental evaluation • To verify the calculated sidelobe feature, we fabricated a scaled model (1:3) with F/#=3.5 Crossed- Dragone telescope. • We measured the main and far sidelobe pattern at 200 GHz and compared with the GRASP10. • We will also study the mitigation of the main beam and sidelobe pattern using various baffle configurations • The measurements are ongoing and the results are soon to be reported. Experimental setup at JAXA 20 LiteBIRD Design of high frequency telescope Strehl ratio @340GHz over2-dimensional 13x13deg SD2 hft200x26 f=440 oal=600 2asp (HFT) 1.00001.000 Parallel to Spin axis ~5K 0.98250.983 Cooled Aperture Si lens 0.9650 <> 0.965 Strehl Definition, xan = 6.6, yan = 6.6 Max.SD = 0.99938198 Min.SD = 0.94754979 Telecentric Ghost analysis by using LightTools F/#=2.2 <10K 100mK Si lens Focal Plane 200mm Stray Light analysis by using LightTools High Frequency (280-402GHz) telescope Two plano-convex aspherical Si lenses (φ<250mm). Cryogenically cooled entrance aperture to control sidelobe of feed. 21 LiteBIRD Low-Frequency Array Focal plane for LFT SQUID Arrays (4K) 100 mK Cooler Mid-Frequency Array 10 cm 22 LiteBIRD Low- and Mid-Frequency Arrays UC Berkeley Sinuous, 3-band and 4-band pixels • Sinuous Antenna Broadband Trichroic Pixels • 3:1 Bandwidth enables high band count within fixed field- of-view 23 LiteBIRD Array for HFT 10 cm 24 High-Frequency Array LiteBIRD A: Nb probes B: microstrip NIST C: filters D: TES bolometer D A B C 90 150 220 90/150 220/350 • Horn Coupled Array: Demonstrated performance at high frequency.