Yasuo Takeuchi

D.Sc., Tokyo Inst. of Tech, 1995 Professor Particle Physics Group Office: Room 314, Science and Technology Research Building No.3 Phone: 078-803-5634 E-mail: Personal web page

Research objectives

Those observations that cosmic rays could become a possible background source should be done in the deep underground laboratories, since the flux of the cosmic-ray muons are very small in deep underground. I have been working on the experiments in astrophysics and particle physics in deep underground, like XMASS and Super-Kamiokande. Super-Kamiokande is the largest water Cherenkov detector in the world in Kamioka Observatory in Japan. XMASS is the experiment to try to observe the dark matter directly with 1-ton of very clean liquid xenon scintillator. The dark matter has not been detected directly with high confidence level yet, but it would be new elementary particles. In XMASS, our goal is to detect the dark matter directory with factor 100 better sensitiivity than the current observations. I have been also working on the research and development of the measurement technique for very small amount of impurities, like radon, in pure gases and in pure water.

Main Publications

• M.Ikeda, T.Hokama, S.Tasaka, Y.Takeuchi ``Adsorption and Desorption of Radon in Argon Gas, and the Development of Low Level Radon Concentration Measurement Method'' RADIOISOTOPES 59 (2010) 29.
• The XMASS Collaboration ``Distillation of liquid xenon to remove krypton'' Astropart. Phys. 31 (2009) 290.
• The Super-Kamiokande Collaboration, ``Solar neutrino measurements in Super-Kamiokande-I'' Phys. Rev. D73, (2006) 112001.
• The SNO Collaboration, ``Electron Energy Spectra, Fluxes, and Day-Night Asymmetries of 8B Solar Neutrinos from the 391-Day Salt Phase SNO Data Set'' Phys. Rev. C72, (2005) 055502.
• C.Mitsuda, T.Kajita, K.Miyano, S.Moriyama, M.Nakahata, Y.Takeuchi, and S.Tasaka ``Development of Super-high Sensitivity Radon Detector for the Super-Kamiokande Detector'' Nucl. Instr. and Meth. A497(2003)414.
• Y.Takeuchi, T.Tanimori, and Y.Yasu ``Development of data acquisition system using RISC/UNIX workstation'' Nucl. Instr. and Meth. A328(1993)526-534.