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 ...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.展开更多
Four high-purity germanium 4-fold segmented Clover detectors have been applied in the experiment of neutron-rich nucleus 21N. The performance of those four Clovers have been tested with radioactive sources and in-beam...Four high-purity germanium 4-fold segmented Clover detectors have been applied in the experiment of neutron-rich nucleus 21N. The performance of those four Clovers have been tested with radioactive sources and in-beam experiments, and the main results including energy resolution, peak-to-total ratios, the variation of the hit pattern distribution in different crystals of one Clover detector with the energy of γ ray, and absolute full energy peak detection effciency curve, were presented.展开更多
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.
文摘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 National Basic Research Program (973 program) of China (2007CB815000, 2005CB724800) National Natural Science Foundation of China (10775003,10475004, 10405001, 10221003, J0730316)
文摘Four high-purity germanium 4-fold segmented Clover detectors have been applied in the experiment of neutron-rich nucleus 21N. The performance of those four Clovers have been tested with radioactive sources and in-beam experiments, and the main results including energy resolution, peak-to-total ratios, the variation of the hit pattern distribution in different crystals of one Clover detector with the energy of γ ray, and absolute full energy peak detection effciency curve, were presented.
