Astrophys. Space Sci. Trans., 7, 15-20, 2011
© Author(s) 2011. This work is distributed
under the Creative Commons Attribution 3.0 License.
19 Jan 2011
Cosmic-ray energy spectrum around the knee observed with the Tibet air-shower experiment
M. Amenomori1, X. J. Bi2, D. Chen3, S. W. Cui4, Danzengluobu5, L. K. Ding2, X. H. Ding5, C. Fan6, C. F. Feng6, Zhaoyang Feng2, Z. Y. Feng7, X. Y. Gao8, Q. X. Geng8, Q. B. Gou2, H. W. Guo5, H. H. He2, M. He6, K. Hibino9, N. Hotta10, Haibing Hu5, H. B. Hu2, J. Huang2, Q. Huang7, H. Y. Jia7, L. Jiang2,8, F. Kajino11, K. Kasahara12, Y. Katayose13, C. Kato14, K. Kawata3, Labaciren5, G. M. Le15, A. F. Li6, H. C. Li2,4, J. Y. Li6, C. Liu2, Y.-Q. Lou16, H. Lu2, X. R. Meng5, K. Mizutani12,17, J. Mu8, K. Munakata14, H. Nanjo1, M. Nishizawa18, M. Ohnishi3, I. Ohta19, S. Ozawa12, T. Saito20, T. Y. Saito21, M. Sakata11, T. K. Sako13, M. Shibata13, A. Shiomi22, T. Shirai9, H. Sugimoto23, M. Takita3, Y. H. Tan2, N. Tateyama9, S. Torii12, H. Tsuchiya24, S. Udo9, B. Wang2, H. Wang2, Y. Wang2, Y. G. Wang6, H. R. Wu2, L. Xue6, Y. Yamamoto11, C. T. Yan25, X. C. Yang8, S. Yasue26, Z. H. Ye27, G. C. Yu7, A. F. Yuan5, T. Yuda9, H. M. Zhang2, J. L. Zhang2, N. J. Zhang6, X. Y. Zhang6, Y. Zhang2, Yi Zhang2, Ying Zhang2,7, Zhaxisangzhu5, and X. X. Zhou7
The Tibet ASγ Collaboration
1Department of Physics, Hirosaki University, Hirosaki 036-8561, Japan
2Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
3Institute for Cosmic Ray Research, University of Tokyo, Kashiwa 277-8582, Japan
4Department of Physics, Hebei Normal University, Shijiazhuang 050016, China
5Department of Mathematics and Physics, Tibet University, Lhasa 850000, China
6Department of Physics, Shandong University, Jinan 250100, China
7Institute of Modern Physics, SouthWest Jiaotong University, Chengdu 610031, China
8Department of Physics, Yunnan University, Kunming 650091, China
9Faculty of Engineering, Kanagawa University, Yokohama 221-8686, Japan
10Faculty of Education, Utsunomiya University, Utsunomiya 321-8505, Japan
11Department of Physics, Konan University, Kobe 658-8501, Japan
12Research Institute for Science and Engineering, Waseda University, Tokyo 169-8555, Japan
13Faculty of Engineering, Yokohama National University, Yokohama 240-8501, Japan
14Department of Physics, Shinshu University, Matsumoto 390-8621, Japan
15National Center for Space Weather, China Meteorological Administration, Beijing 100081, China
16Physics Department and Tsinghua Center for Astrophysics, Tsinghua University, Beijing 100084, China
17Saitama University, Saitama 338-8570, Japan
18National Institute of Informatics, Tokyo 101-8430, Japan
19Sakushin Gakuin University, Utsunomiya 321-3295, Japan
20Tokyo Metropolitan College of Industrial Technology, Tokyo 116-8523, Japan
21Max-Planck-Institut für Physik, 80805 Munich, Germany
22College of Industrial Technology, Nihon University, Narashino 275-8576, Japan
23Shonan Institute of Technology, Fujisawa 251-8511, Japan
24RIKEN, Wako 351-0198, Japan
25Institute of Disaster Prevention Science and Technology, Yanjiao 065201, China
26School of General Education, Shinshu University, Matsumoto 390-8621, Japan
27Center of Space Science and Application Research, Chinese Academy of Sciences, Beijing 100080, China

Abstract. The energy spectrum of cosmic rays around the knee measured by Tibet air-shower experiment is summarized and its characteristic features are discussed under two possible scenarios. The result of Tibet experiment measured over wide range of 1014–1017 eV with high statistics provided details of the knee at the energy around 4×1015 eV. The study of the chemical composition based on measurements of proton and helium spectra obtained from air-shower core detection indicates the dominance of heavy nuclei around the knee. Such feature can be explained either by contribution of nearby sources with source composition dominated by heavy nuclei or by nonlinear effect in diffusive shock acceleration mechanism.

Citation: Amenomori, M., Bi, X. J., Chen, D., Cui, S. W., Danzengluobu, Ding, L. K., Ding, X. H., Fan, C., Feng, C. F., Zhaoyang Feng, Feng, Z. Y., Gao, X. Y., Geng, Q. X., Gou, Q. B., Guo, H. W., He, H. H., He, M., Hibino, K., Hotta, N., Haibing Hu, Hu, H. B., Huang, J., Huang, Q., Jia, H. Y., Jiang, L., Kajino, F., Kasahara, K., Katayose, Y., Kato, C., Kawata, K., Labaciren, Le, G. M., Li, A. F., Li, H. C., Li, J. Y., Liu, C., Lou, Y.-Q., Lu, H., Meng, X. R., Mizutani, K., Mu, J., Munakata, K., Nanjo, H., Nishizawa, M., Ohnishi, M., Ohta, I., Ozawa, S., Saito, T., Saito, T. Y., Sakata, M., Sako, T. K., Shibata, M., Shiomi, A., Shirai, T., Sugimoto, H., Takita, M., Tan, Y. H., Tateyama, N., Torii, S., Tsuchiya, H., Udo, S., Wang, B., Wang, H., Wang, Y., Wang, Y. G., Wu, H. R., Xue, L., Yamamoto, Y., Yan, C. T., Yang, X. C., Yasue, S., Ye, Z. H., Yu, G. C., Yuan, A. F., Yuda, T., Zhang, H. M., Zhang, J. L., Zhang, N. J., Zhang, X. Y., Zhang, Y., Yi Zhang, Ying Zhang, Zhaxisangzhu, and Zhou, X. X.: Cosmic-ray energy spectrum around the knee observed with the Tibet air-shower experiment, Astrophys. Space Sci. Trans., 7, 15-20, doi:10.5194/astra-7-15-2011, 2011.
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