Lifetimes of the TSD candidate bands in 157,158Er at ultra high spin

157、158Er核在很高自旋时既有单粒子结构又有集体结构。这一结论是基于对伽马射线能量和能级的测量。在这两个原子核中都发现了高自旋的转动带。基于测量的伽马射线能量，该带具有变形带的特征。从伽马射线能量可以推导出的惯性矩低于超形变带的预期，其作为自旋函数的行为就像在较重的核中发现的三轴带。在这个实验中，将测量寿命，然后可以用来确定过渡强度。这是一个更精确的测量变形和三轴性比单独的伽马射线能量。该实验将在美国阿贡国家实验室使用伽马球阵列进行。数据将收集12天。然后，这些数据将在利物浦进行分析，以实现物理目标。这些数据将成为研究生论文的一部分。

The nuclei 157,158Er have both single particle and collective structures at very high spin. This conclusion has been based on the measurement of gamma ray energies and energy levels. Rotational bands have been found at very high spin in both nuclei. Based on the gamma ray energies measured this band has the characteristics of a deformed band. The moment of inertia that can be deduced from the gamma ray energies is lower than expected from a superdeformed band and its behaviour as a function of spin is like that in triaxial bands found in heavier nuclei. In this experiment lifetimes will be measured which can then be used to determine transition strengths. These are a more exact measure of both deformation and triaxiality than the gamma ray energies alone. The experiment will be carried out using the GAMMASPHERE array at Argonne National Laboratory in the USA. Data will be collected for 12 days. The data will then be analysed in Liverpool in order to achieve the physics aims. The data will form part of the thesis of a resarch student.