Beta-delayed neutron and gamma-ray spectroscopy of ^<17>C utilizing spin-polarized ^<17>B
Beta-delayed neutron and gamma-ray spectroscopy of ^<17>C utilizing spin-polarized ^<17>B
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利用自旋极化^<17>B的^<17>C的β延迟中子和伽马射线能谱
DOI：
10.1103/physrevc.87.034316
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
他
中科院分区：
文献类型：
--
作者：
H. Ueno;K. Asahi;他
通过测量 B 衰变中发射的延迟中子和射线来研究 C 中的激发态。测量中，在中子阈值能量以上的C中识别出3个负宇称态和2个不确定态，在B衰变的a延迟多重中子发射中识别出7条线。根据这些转变，确定了 B 的衰变方案。特别是，在发射延迟中子的同时观察到来自 C 第一激发态的去激发 1766-keV 线，这改变了先前报道的 B 的衰变方案和 C 的能级结构。在目前的工作中，核磁共振技术与使用碎片诱导自旋极化 B 束的延迟粒子测量相结合。这个新方案使我们能够根据离散衰变不对称参数的差异来确定衰变馈送激发态的自旋宇称，前提是这些态通过伽莫夫-泰勒跃迁连接。在这项工作中，、、和 () 分别分配给 2.71(2)、3.93(2) 和 4.05(2) MeV inC 处的观测状态。
Excited states inC were investigated through the measurement of-delayed neutrons andrays emitted in thedecay ofB. In the measurement, three negative-parity states and two inconclusive states were identified inC above the neutron threshold energy, and sevenlines were identified in a-delayed multiple neutron emission of theBdecay. From these transitions, the-decay scheme ofB was determined. In particular, a de-excitation 1766-keVline from the first excited state ofC was observed in coincidence with the emitted-delayed neutrons, and this changes the previously reported-decay scheme ofB and level structure ofC. In the present work, the-NMR technique is combined with the-delayed particle measurements using a fragmentation-induced spin-polarizedB beam. This new scheme allows us to determine the spin parity of-decay feeding excited states based on the difference in the discrete-decay asymmetry parameters, provided the states are connected through the Gamow-Teller transition. In this work,,, and () are assigned to the observed states at2.71(2), 3.93(2), and 4.05(2) MeV inC, respectively.