Shape co-existence in neutron-rich A~110 nuclei

每个原子的中心都有一个核，有关核如何行为的信息与许多领域有关，包括医学诊断，有时还包括治疗、核动力等。因此，我们必须建立一幅核在不同情况下如何反应的图。例如，为什么有些原子核是稳定的，或者，如果它们确实衰变了，为什么它们用一种特殊的方法这样做？为什么原子核呈现出不同的形状？是什么力量驱使它们形成这些形状？可能有6000种中子和质子的组合可以粘在一起形成原子核，这些原子核的寿命足够长，足以被观测到。在自然界中，只有大约300个原子核存在，而我们对原子核及其性质的大部分知识都来自对这300个原子核的详细研究。因此，为了测试我们的核力量模型，我们必须制造和研究新的系统。通常情况下，当我们使原子核处于激发状态时，它会在一秒内衰变(通常约为1除以10，其后为15个零)。有时，原子核会卡在一种特定的构型中，然后这种构型的寿命会超过万亿分之一秒。我们称这些态为同分异构态，这项研究计划是为了寻找预测存在于重锆核中的这些态。实验的目标不仅是发现这些状态，而且一旦发现它们，如果它们确实存在，我们建议测量它们的性质，并根据模型预测对它们进行测试。这种比较的结果将被用来进一步改进模型，以便它们可以被用来推断出它们所针对的原子核之外的情况。因此，这些信息将使我们更清楚地了解原子核的行为，从而使我们能够最大限度地利用它们。

At the centre of every atom there is a nucleus and information about how nuclei behave is relevant to many areas, including medical diagnosis and sometimes therapy, nuclear power etc. Hence it is important that we build up a picture of how nuclei react under different circumstances. For example why are some nuclei stable or, if they do decay, why do they do so by a particular method? Why do nuclei take on different shapes and what are the forces which drive them to these shapes? There are possibly 6000 combinations of neutrons and protonswhich could stick together to form nuclei that would live long enough tobe observed. Of these only about 300 exist in nature and most of ourknowledge of nuclei and their properties comes from the detailedstudy of these 300. Hence in order to test our models of nuclear forces, we have to make and study new systems. Normally when we make a nucleus in an excited state, it decays within a fraction (typically about 1 divided by 10 with 15 noughts after it) of a second . Sometimes a nucleus gets stuck in one particular configuration which then lives for a time longer than 1 thousand millionth of a second. We call these states isomeric and this research proposal is to search for such states which are predicted to exist in the heavy zirconium nuclei. It is not just the finding of these states which is the experimental goal but once they are found, if indeed they do exist, we propose to measure their properties and test them against the model predictions. The results of this comparison will be used to further refine the models so that they can be used to extrapolate beyond the nuclei for which they were developed. This information will therefore give us a clearer view of how nuclei behave and hence will enable us to use them to their maximum potential.