LOU Jian-Ling1, LI Zhi-Huan1, YE Yan-Lin1, JIANG Dong-Xing1, HUA Hui1, LI Xiang-Qing1, ZHANG Shuang-Quan1, ZHENG Tao1, GE Yu-Chen1, KONG Zan1, LV Lin-Hui1, LI Chen1, LU Fei1, FAN Feng-Ying1, LI Zhong-Yu1, CAO Zhong-Xin1, MA Li-Ying1, Faisal1, XU Hu-Shan2, HU Zheng-Guo2, WANG Meng2, LEI Xiang-Guo2, DUAN Li-Min2, XIAO Zhi-Gang2, ZHAN Wen-Long2, XIAO Guo-Qing2, HUANG Tian-Heng2, FU Fen2, ZHANG Xue-Heng2, ZHENG Chuan2, YU Yu-Hong2, TU Xiao-Lin2, ZHANG Ya-Peng2, YANG Yan-Yun2, ZHANG Hong-Bin2, TANG Bin2, TIAN Yu-Lin2, OU Yang-Zhen2, HUANG Mei-Rong2, XU Zhi-Guo2, YUE Ke2, GAO Qi2
1School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 1008712Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000
1School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 1008712Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000
摘要The β-delayed neutron and γ energy spectra taken from the decay of neutron-rich nucleus 21N were measured by using the β-γ and β-n coincidence detection method. Thirteen new neutron groups ranging from 0.28MeV to 4.98MeV and with a total branching ratio of 88.7±4.2% were observed and presented. One γ transition with an energy of 1222keV emitted from the excited state of 21O, and four γ transitions with energies of 1674, 2397, 2780, and 3175keV emitted from the excited states of 20O were identified in the β decay chain of 21N. The β decay half-life for 21N is determined to be 82.9±1.9ms. The uncertainty of half-life is much smaller than the previous result.
Abstract：The β-delayed neutron and γ energy spectra taken from the decay of neutron-rich nucleus 21N were measured by using the β-γ and β-n coincidence detection method. Thirteen new neutron groups ranging from 0.28MeV to 4.98MeV and with a total branching ratio of 88.7±4.2% were observed and presented. One γ transition with an energy of 1222keV emitted from the excited state of 21O, and four γ transitions with energies of 1674, 2397, 2780, and 3175keV emitted from the excited states of 20O were identified in the β decay chain of 21N. The β decay half-life for 21N is determined to be 82.9±1.9ms. The uncertainty of half-life is much smaller than the previous result.
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2008, Vol. 25 
