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

原子核157,158Er在非常高的自旋下具有单粒子和集体结构。这个结论是基于对伽马射线能量和能级的测量得出的。在两个原子核的高自旋处都发现了旋转带。根据测量的伽马射线能量，该波段具有变形带的特征。从伽马射线能量中可以推断出的转动惯量比从超变形带中得到的要低，它的自旋函数的行为类似于在较重的原子核中发现的三轴带。在这个实验中，寿命将被测量，然后可以用来确定过渡强度。这是一种比单独的伽马射线能量更精确的测量变形和三轴性的方法。该实验将使用美国阿贡国家实验室的GAMMASPHERE阵列进行。数据收集时间为12天。然后，这些数据将在利物浦进行分析，以实现物理目标。这些数据将构成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.