Browsing by Autor "T. Sakai"

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EMISIÓN NEUTRÓNICA SOLAR DE LARGA DURACIÓN COMPARADA CON LA RADIACIÓN PRODUCIDA POR ELECTRONES EN LA FULGURACIÓN SOLAR DEL 7 DE SEPTIEMBRE DE 2005
(2007) Takeshi SAKO; K. Watanabe; Y. Muraki; Y. Matsubara; H. Tsujihara; M Yamashita; T. Sakai; S. Shibata; Jose F. Valdés Galicia; L. X. González
T.Sako, K.Watanabe, Y.Muraki, Y.Matsubara, H.Tsujihara, M.Yamashita, T.Sakai, S.Shibata, J.F.Valdes-Galicia, L.X.Gonzalez, A.Hurtado, O.Musalem, P.Miranda, N.Martinic, R.Ticona, A.Velarde, F.Kakimoto, S.Ogio, Y.Tsunesada, H.Tokuno, Y.T.Tanaka, I.Yoshikawa, T.Terasawa, Y.Saito, T.Mukai, y M.Gros 1 Solar-Terrestrial Environment Laboratory, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan. 2 College of Industrial Technologies, Nihon University, 2-11-1 Shinei, Narashino, Chiba 275-0005, Japan. 3 College of Engineering, Chubu University, Kasugai, Aichi 487-8501, Japan. 4 Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, Coyoacan DF 04510, Mexico. 5 Instituto de Investigaciones Fisicas, Universidad Mayor de San Andres, La Paz, Bolivia. 6 Department of Physics, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan. 7 Graduate School of Science, Osaka City University, Osaka 558-8585, Japan. 8 Department of Earth and Planetary Science, University of Tokyo, Tokyo 113-0033, Japan. 9 ISAS/JAXA, Sagamihara 229-8510, Japan. 10 DSM/DAPNIA/SAp, CEA Saclay, 91191 Gif-sur-Yvette, France.
Highly significant detection of solar neutrons on 2005 September 7
(Elsevier BV, 2007) K. Watanabe; T. Sako; Y. Muraki; Y. Matsubara; T. Sakai; S. Shibata; Jose F. Valdés Galicia; L. X. González; A. Hurtado; O. Musalém
Long-lived Solar Neutron Emission in Comparison with Electron-produced Radiation in the 2005 September 7 Solar Flare
(IOP Publishing, 2006) T. Sako; K. Watanabe; Y. Muraki; Y. Matsubara; H. Tsujihara; M. T. Yamashita; T. Sakai; S. Shibata; Jose F. Valdés Galicia; L. X. González
Strong signals of neutral emissions were detected in association with a solar flare that occurred on 2005 September 7. They were produced by both relativistic ions and electrons. In particular, relativistic neutrons were observed with the solar neutron telescopes (SNTs) located at Mount Chacaltaya in Bolivia and Mount Sierra Negra in Mexico and with neutron monitors (NMs) at Chacaltaya and Mexico City with high statistical significances. At the same time, hard X-rays and γ-rays, which were predominantly emitted by high-energy electrons, were detected by the Geotail and the INTEGRAL satellites. We found that a model of the impulsive neutron emission at the time of the X-ray/γ-ray peak can explain the main peaks of all the detected neutron signals, but failed to explain the long tailed decaying phase. An alternative model, in which the neutron emission follows the X-ray/γ-ray profile, also failed to explain the long tail. These results indicate that the acceleration of ions began at the same time as the electrons but that ions were continuously accelerated or trapped longer than the electrons in the emission site. We also demonstrate that the neutron data observed by multienergy channels of SNTs put constraints on the neutron spectrum.
Proton penetration efficiency over a high altitude observatory in Mexico
(SciPost.org, 2023) Shoko Miyake; T. Koi; Y. Muraki; Y. Matsubara; S. Masuda; P. Miranda; T. Naito; E. Ortiz; A. Oshima; T. Sakai
In association with a large solar flare on November 7, 2004, the solar neutron detectors located at Mt. Chacaltaya (5,250 m) in Bolivia and Mt. Sierra Negra (4,600 m) in Mexico recorded very interesting events. In order to explain these events, we have performed a calculation solving the equation of motion of anti-protons inside the magnetosphere. Based on these results, the Mt. Chacaltaya event may be explained by the detection of solar neutrons, while the Mt. Sierra Negra event may be explained by the first detection of very high energy solar neutron decay protons (SNDPs) around 6 GeV.
Report on scipost_202207_00031v1
(2022) Shoko Miyake; T. Koi; Y. Muraki; Y. Matsubara; S. Masuda; Pedro Miranda; T. Naito; E. Ortiz; A. Oshima; T. Sakai
In association with a large solar flare on November 7, 2004, the solar neutron detectors located at Mt. Chacaltaya (5,250 m) in Bolivia and Mt.Sierra Negra (4,600 m) in Mexico recorded very interesting events.In order to explain these events, we have performed a calculation solving the equation of motion of anti-protons inside the magnetosphere.Based on these results, the Mt.Chacaltaya event may be explained by the detection of solar neutrons, while the Mt.Sierra Negra event may be explained by the first detection of very high energy solar neutron decay protons (SNDPs) around 6 GeV.
Status of the world-wide network of solar neutron telescopes in solar cycle 24
(2009) Y. Matsubara; Y. Muraki; T. Sako; Y. Itow; T. Sakai; S. Shibata; T. Yuda; M. Ohnishi; H. Tsuchiya; Y. Katayose
A network of solar neutron telescopes has been developed since the middle of solar cycle 22. We have detected several important solar neutron events until the end of solar cycle 23 using solar neutron telescopes, but the accumulation of more solar neutron events is indispensable to eclucidate the acceleration mechanism of high energy particles. The data of the solar magnetic field with a space resolution of 0.3 arcsec obtained by Hinode satellite will be useful to understand solar neutron events more efficiently than during the previous solar cycles. In this paper we discuss the expected scientific results obtained by the world-wide network of solar neutron telescopes during solar cycle 24.