The POLARBEAR-2 experiment

Takayuki Tomaru, Masashi Hazumi, Adrian T. Lee, Peter Ade, Kam Arnold, Darcy Barron, Julian Borrill, Scott Chapman, Yuji Chinone, Matt Dobbs, Josquin Errard, Giullo Fabbian, Adnan Ghribi, William Grainger, Nils Halverson, Masaya Hasegawa, Kaori Hattori, William L. Holzapfel, Yuki Inoue, Sou IshiiYuta Kaneko, Brian Keating, Zigmund Kermish, Nobuhiro Kimura, Ted Kisner, William Kranz, Frederick Matsuda, Tomotake Matsumura, Hideki Morii, Michael J. Myers, Haruki Nishino, Takahiro Okamura, Erin Quealy, Christian L. Reichardt, Paul L. Richards, Darin Rosen, Colin Ross, Akie Shimizu, Michael Sholl, Praween Siritanasak, Peter Smith, Nathan Stebor, Radek Stompor, Aritoki Suzuki, Jun Ichi Suzuki, Suguru Takada, Ken Ichi Tanaka, Oliver Zahn

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

22 Scopus citations


POLARBEAR-2 (PB-2) is a cosmic microwave background (CMB) polarization experiment observing at Atacama plateau in Chile. PB-2 is designed to improve the sensitivity to measure the CMB B-mode polarization by upgrading the current POLARBEAR-1 receiver that is currently mounted on the Huan Tran telescope. The improvements in PB-2 include, i) the dual band observations at 95 GHz and 150 GHz in each pixel using an sinuous antenna, ii) the increase of the total number of detectors, 7588 Al-Ti bilayer transition-edge sensor (TES) bolometers, iii) the bath temperature of bolometers at 100mK in the second phase of observation (300mK in the first phase.) With the expected sensitivity of 5.7 μK √s, PB-2 is sensitive to a tensor-to-scalar ratio, r, of 0.01 at 95% confidence level (CL) and constrains the sum of neutrino masses as 90meV by PB-2 alone and 40meV by combining PB-2 and Planck at 68% CL. We schedule to deploy in 2014.

Original languageEnglish
Title of host publicationMillimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VI
StatePublished - 2012
EventMillimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VI - Amsterdam, Netherlands
Duration: 3 Jul 20126 Jul 2012

Publication series

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


ConferenceMillimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VI


  • B-mode
  • Bolometer
  • Cosmic microwave background
  • Gravitational lensing
  • Gravitational wave
  • Neutrino mass
  • Polarization


Dive into the research topics of 'The POLARBEAR-2 experiment'. Together they form a unique fingerprint.

Cite this