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 0.28 MeV to 4.98 MeV and with a total branching ratio of 88.7±4.2% were observed and presented. One γ transition with an energy of 1222 keV 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.
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 0.28 MeV to 4.98 MeV and with a total branching ratio of 88.7±4.2% were observed and presented. One γ transition with an energy of 1222 keV 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.
基金
Supported by the National Basic Research Programme of China under Grant Nos 2007CB815000 and 2005CB724800, the National Natural Science Foundation of China under Grant Nos 10775003,10475004, 10405001, 10221003 and J0730316.
