Exotic nuclear systems probed with transfer reactions using solenoid spectrometers

原子核由质子和中子组成，质子和中子的数量决定了元素和同位素。这些中子和质子如何相互作用决定了任何单个原子核的性质，例如它的结构、形状以及它是稳定的还是具有放射性的。原子核的这些性质及其经历的过程，如核裂变，可以决定我们在自然界中观察到的元素的丰度。这些元素以许多不同的方式产生，在宇宙中许多不同的天体物理过程中产生；例如最近观察到的中子星合并。我们还没有完全了解原子核中中子和质子之间的作用力，没有一个理论模型可以描述核图中的每个原子核。同样，我们对核裂变的理解仅限于接近稳定的系统。为了了解整个核图上所有核的行为，以及它们是如何在这些天体物理过程中产生的，核物理学家必须研究那些只存在很短时间的核，在许多情况下不到一秒。这需要最先进的设施和技术。对于核物理研究来说，令人兴奋的是，一些升级或新的生产放射性原子核作为研究束流的设施即将开始运行。这些设施包括欧洲核子研究中心升级后的HIE-Isolde设施和美国的稀有同位素束设施。与这些设备相结合的是研究这些短寿命原子核光束上的核反应的最新技术，这些技术是基于从以前的医院核磁共振机器上重新调整用途的磁铁。这次联谊会的目的是使用这些新设备通过一种称为转移反应的方法来研究原子核的结构。在转移反应中，可以在感兴趣的放射性原子核中添加或移除单个中子或质子，以研究该单个粒子在不同原子核中的行为。我将研究从原子核中移除单个质子的反应，以研究这个质子的行为，以及它如何与该原子核中的中子相互作用，从而提供关于中子和质子之间基本力的信息。我还将利用这些反应在短寿命系统中诱导裂变，以研究放射性原子核如何通过这一途径衰变，并测量产生的元素及其同位素的分布。这将使我们能够研究更短寿命系统中的裂变，提高我们对这一过程的理解，并预测它是如何在中子星合并等现象中产生的非常奇异的核中发生的。

Atomic nuclei consist of protons and neutrons, the numbers of which determine the element and the isotope. How these neutrons and protons interact defines the properties of any individual nucleus, for example its structure, its shape and whether it is stable or radioactive. These properties of atomic nuclei and the processes they undergo, such as nuclear fission, can then determine the abundance of the elements that we observe in nature. These elements are produced in many different ways, in many different astrophysical processes throughout the universe; such as neutron-star mergers, which have recently been observed. We do not yet fully understand the forces between neutrons and protons in nuclei, there is no one theoretical model that can describe every nucleus in the nuclear chart. Similarly our understanding of nuclear fission is limited in scope to systems near stability.In order to understand the behavior of all nuclei across the nuclear chart, and how they are produced in these astrophysical processes, nuclear physicists have to study nuclei that live for only a very short amount of time, less than a second in many cases. This requires state-of-the-art facilities and techniques. Excitingly for nuclear physics research, a number of upgraded or new facilities that produce radioactive nuclei as beams for study are soon to start operation. These include the upgraded HIE-ISOLDE facility at CERN and the Facility for Rare Isotope Beams in the USA. Coupled to these facilities are the latest technologies for studying nuclear reactions on these beams of short-lived nuclei, based on repurposed magnets from former hospital MRI machines.The aim of this Fellowship is to use these new devices to study the structure of nuclei using a method known as transfer reactions. In transfer reactions a single neutron or proton can be added to or taken away from a radioactive nuclei of interest, to study how that single particle behaves in different nuclei. I will look at reactions that remove a single proton from a nucleus to investigate how that one proton behaves, and how it interacts with the neutrons in that nucleus, providing information on the fundamental forces between neutrons and protons. I will also use these reactions to induce fission in short-lived systems to study how radioactive nuclei decay via this pathway and measure the distributions of elements and their isotopes that are produced. This will allow the study of fission in more short-lived systems, improving our understanding of this process and predictions of how it occurs in the very exotic nuclei produced in phenomena such as neutrons star mergers.