Observation of solar neutrons at high altitudes near the equator

• Project/Area Number: 16540242
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Nagoya University
• Principal Investigator: MATSUBARA Yutaka Nagoya University, Solar-Terrestial Environment Laboratory, Associate Professor, 太陽地球環境研究所, 助教授 (80202323)
• Project Period (FY): 2004 – 2005
• Project Status: Completed (Fiscal Year 2005)
• Budget Amount: ¥3,600,000 (Direct Cost: ¥3,600,000); Fiscal Year 2005: ¥1,600,000 (Direct Cost: ¥1,600,000); Fiscal Year 2004: ¥2,000,000 (Direct Cost: ¥2,000,000)
• Keywords: network of solar neutron detector / high altitude near the equator / particle acceleration / Chacaltaya / Sierra Negra / automatic data taking / solar flare / 2005 September 7 / 太陽表面粒子加速 / 大陽中性子 / 24時間観測網 / 赤道付近の高山 / 次期太陽活動期の拠点 / Linux / メキシコの装置

Research Abstract

This research aims to clarify the acceleration mechanism of high energy particles at the solar surface, by observing on the ground high energy solar neutrons (>100MeV) produced by the interaction between accelerated protons and the solar atmosphere. It is more preferable to use neutrons than protons to study solar acceleration, because neutrons are not reflected by the interplanetary magnetic field. In order to detect solar neutrons effectively, the group which mainly includes Solar-Terrestrial Environment Laboratory, Nagoya University, has completed a network of solar neutron detectors in the world to observe the Sun for a whole day. These detectors are located at high mountains near the equator, because solar neutrons are attenuated while propagating in the air. According to the Grant-in-Aid for Scientific Research, the data taking system of the solar neutron detector at Chacaltaya in Bolivia, which was designed more than 15 years ago, has been replaced by a quite a new system, by wh ich a data taking starts automatically after a power cut of the electricity. Chacaltaya (altitude : 5250m, latitude : 16 degrees S) is the best place to observe solar neutrons in our network. This experience was useful to adopt the same system to the detector at Sierra Negra in Mexico, where nobody stays permanently. Sierra Negra (altitude : 4600m, latitude : 19 degrees N) the second best place to observe solar neutrons. These new systems are believed to work properly during the next solar cycle, which will start in 2007, and, we bacame to detect solar neutrons much more efficiently than before. While we were improving both systems, a large solar flare occurred on September 7, 2005. The solar neutron detectors both at Chacaltaya and Sierra Negra have succeeded in detecting solar neutron signals, which are the most significant ones so far obtained by our detectors. Moreover, neutron monitors at Chacaltaya and Mexico City also detected clear signals. The analysis on this events is now in progress, but obtaing this kind of event is what we have aimed by this Grant-in-Aid for Scientific Research.

Research Products

• [Journal Article] Solar neutron events of October-November 20003 (2006)
  • Author(s): K.Watanabe, M.Gros, P.H.Stoker, Y.Matsubara 他
  • Journal Title: Astrophys. J. 636 Pages: 1135-1144
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Solar neutron events of October-November 2003 (2006)
  • Author(s): K.Watanabe, M.Gros, P.H.Stoker, K.Kudela, C.Lopate, J.F.Valdes-Galicia, A.Hurtado, O.Musalem, R.Ogasawara, Y.Mizumoto, M.Nakagiri, A.Miyashita, Y.Matsubara, T.Sako, Y.Muraki, T.Sakai, S.Shibata
  • Journal Title: Astrophys.J. 636 Pages: 1135-1144
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Solar neutron events of October-November 2003 (2006)
  • Author(s): K.Watanabe, M.Gros, P.H.Stoker, Y.Matsubara 他
  • Journal Title: Astrophys.J. 636 Pages: 1135-1144
• [Journal Article] Search for solar neutrons associated with proton flares in solar cycle 23 (2006)
  • Author(s): Y.Matsubara, Y.Muraki, T.Sako, K.Watanabe 他
  • Journal Title: Proc.29th Int.Cosmic Ray Conf. (印刷中)
• [Journal Article] Solar neutron events associated with large solar flares in solar cycle 23 (2006)
  • Author(s): K.Watanabe, Y.Muraki, Y.Matsubara, T.Sako 他
  • Journal Title: Proc.29th Int.Cosmic Ray Conf. (印刷中)
• [Journal Article] Possible >10 GeV particle detection in association with the 28 May 2003 solar flare (2006)
  • Author(s): T.Sako, Y.Muraki, Y.Matsubara, K.Watanabe 他
  • Journal Title: Proc.29th Int.Cosmic Ray Conf. (印刷中)
• [Journal Article] Solar neutron events that have been observed in solar cycle 23 (2005)
  • Author(s): E.Flueckiger, R.Buetikofer, Y.Muraki, Y.Matsubara 他
  • Journal Title: Int. J. Mod. Phys. A 20 Pages: 6646-6649
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] That giant Forbush decrease in October/November 2003 : Data analysis for the solar neutron detector at Gornergrat (2005)
  • Author(s): E.Flueckiger, R.Buetikofer, Y.Muraki, Y.Matsubara 他
  • Journal Title: Int. J. Mod. Phys. A 20 Pages: 6684-6686
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Search for solar neutrons associated with proton flares in solar cycle 23 (2005)
  • Author(s): Y.Matsubara, Y.Muraki, T.Sako, K.Watanabe 他
  • Journal Title: Proc. 29th Int. Cosmic Ray Conf. 1 Pages: 17-20
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Solar neutron events associated with large solar flares in solar cycle 23 (2005)
  • Author(s): K.Watanabe, Y.Muraki, Y.Matsubara, T.Sako 他
  • Journal Title: Proc. 29th Int. Cosmic Ray Conf. 1 Pages: 37-40
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Solar neutron events that have been found in solar cycle 23 (2005)
  • Author(s): E.O.Flueckiger, R.Buetikofer, A.Chilingarian, G.Hovsepyan, Y.H.Tan, T.Yuda, H.Tsuchiya, M.Ohnishi, Y.Katayose, Y.Muraki, Y.Matsubara, T.Sako, K.Watanabe, S.Masuda, T.Sakai, S.Shibata, R.Ogasawara, Y Mizumoto, M.Nakagiri, A.Miyashita, P.H.Stoker, C.Lopate, K.Kudela, M.Gros
  • Journal Title: Int.J.Mod.Phys.A 20 Pages: 6646-6649
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] The giant Forbush decrease in October/November 2003 : Data analysis for the solar neutron detector at Gornergrat (2005)
  • Author(s): E.O.Flueckiger, R.Buetikofer, A.L.Desorgher, M.R.Moser, Y.Muraki, Y.Matsubara, T Sako, H.Tsuchiya, T.Sakai
  • Journal Title: Int.J.Mod.Phys.A 20 Pages: 6684-6686
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Search for solar neutrons associated with proton flares in solar cycle 23 (2005)
  • Author(s): Y.Matsubara, Y Muraki, T.Sako, K.Watanabe, S.Masuda, T.Sakai, S.Shibata, E.Flueckiger, R.Buetikofer, A.Chilingarian, G.Hovsepyan, Y.H.Tan, T.Yuda, M.Ohnishi, H.Tsuchiya, Y.Katayose, R.Ogasawara, Y.Mizumoto, M.Nakagiri, A.Miyashita, A.Velarde, R.Ticona, N.Martinic
  • Journal Title: Proc.29th Int.Cosmic Ray Conf. Vol.1 Pages: 17-20
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Solar neutron events associated with large solar flares in solar cycle 23 (2005)
  • Author(s): K.Watanabe, Y.Muraki, Y.Matsubara, T.Sako, T.Sakai, H.Tsuchiya, S.Shibata, S.Masuda, M.Yoshimori, N.Ohmori, A.Velarde, R.Ticona, N.Martinic, P.Miranda, F.Kakimoto, S.Ogio, Y.Tsunesada, H.Tokuno, Y.Shirasaki, J.F.Valdes-Galicia, A.Hurtado, O.Musalem, L.X.Gonzalez, R.Ogasawara, Y.Mizumoto, M.Nakagiri, A.Miyashita, P.H.Stoker, C.Lopate, K.Kudela, M.Gros
  • Journal Title: Proc.29th Int.Cosmic Ray Conf. Vol.1 Pages: 37-40
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Solar neutron events that have been observed in solar cycle 23 (2005)
  • Author(s): E.Flueckiger, R.Buetikofer, Y.Muraki, Y.Matsubara 他
  • Journal Title: Int.J.Mod.Phys.A 20 Pages: 6646-6649
• [Journal Article] The giant Forbush decrease in October/November 2003 : Data analysis for the solar neutron detector at Gornergrat (2005)
  • Author(s): E.Flueckiger, R.Buetikofer, Y.Muraki, Y.Matsubara 他
  • Journal Title: Int.J.Mod.Phys.A 20 Pages: 6684-6686
• [Journal Article] Solar neutron events that have been found in solar cycle 23 (2005)
  • Author(s): E.Flueckiger, A.Chilingarian, Y.Muraki, Y.Matsubara et al.
  • Journal Title: Proc.19th European Cosmic Ray Physics (印刷中)
• [Journal Article] Cosmic ray from the Sun (2005)
  • Author(s): Y.Matsubara
  • Journal Title: Proc.first school of cosmic rays and astrophysics (印刷中)
• [Journal Article] An improved solar neutron telescope installed at a very high altitude in Mexico (2004)
  • Author(s): J.F.Valdes-Galicia, Y.Muraki, Y.Matsubara 他
  • Journal Title: Nucl. Instr. and Meth. A535 Pages: 656-664
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] An improved solar neutron telescope installed at a very high altitude in Mexico (2004)
  • Author(s): J.F.Valdes-Galicia, Y.Muraki, H.Tsujihara, T.Sako, O.Musalem, A.Hurtabo, L.X.Gonzalez, Y.Matsubara, K.Watanabe, N.Hirano, N.Tateiwa, S.Shibata, T.Sakai
  • Journal Title: Nucl.Instr.and Meth. A535 Pages: 656-664
  • Description: 「研究成果報告書概要(欧文)」より