Spectroscopy of Superheavy Nuclei: The SAGE spectrometer

宇宙的大部分质量是由位于原子中心的原子核组成的。原子核包含带正电的质子和电中性的中子。已知最轻的原子核是只含有一个质子的氢原子核，但还没有人知道原子核的重量;换句话说，究竟有多少中子和质子可以结合在一起。这项提议的目的是通过研究实验室中可以制造的最重的原子核来解决这个问题。这些原子核极难制造和研究。今天最重的人造元素（尚未命名）有多达116个质子，但只有少量的几个原子。质子和中子都被强核力结合在一起，但质子由于它们的电荷而相互排斥。核力的作用距离非常短，只影响最近的邻居，因此，随着越来越多的质子加入到原子核中，静电斥力最终会变得比原子核的束缚力更强，原子核将变得不稳定。中子和质子将不再粘在一起。这应该发生在铀以外的原子核上，铀有92个质子，但更重的物质的存在是因为原子核内部的结构。正如惰性气体的惰性化学行为归功于具有额外稳定性的电子的特定排列，某些“神奇”质子和中子数也增强了核稳定性。该项目关注的是对产生这种额外稳定性并允许“超重”核存在的潜在机制的详细研究。这项工作的主要重点将是围绕着102个质子的诺贝尔核，大约是在铀周围的核和超重元素前沿之间的中间。在这里，光谱学方法可以用来获得详细的了解核的形状和B

The majority of the mass of the universe is made up of atomic nuclei that lie at the centre of the atom. Nuclei contain positively charged protons and electrically neutral neutrons. The lightest known nucleus is that of hydrogen that contains just one proton but no one yet knows how heavy a nucleus can be; in other words, just how many neutrons and protons can be made to bind together. The aim of this proposal is to address this question by studying the heaviest nuclei that can be made in the laboratory. These nuclei are extremely difficult to create and study. The heaviest man-made elements today (unnamed as yet) have as many as 116 protons, but have been produced in tiny quantities of a few atoms only. Both protons and neutrons are held together by the strong nuclear force but protons are repelled from each other because of their electric charge. The nuclear force has an extremely short range, affecting nearest neighbours only, so that, as more and more protons are added to a nucleus the electrostatic repulsion will eventually become stronger than the nuclear binding forces and the nucleus will become unstable. The neutrons and protons will no longer stick together. This should happen for nuclei beyond uranium, which has 92 protons but the existence of heavier species comes about because of the internal structure within the nuclei. Just as noble gases owe their inert chemical behaviour to a specific arrangement of electrons that has extra stability, so certain 'magic' proton and neutron numbers also enhance nuclear stability. This project is concerned with a detailed study of the underlying mechanisms that yield this extra stability and allow 'superheavy' nuclei to exist. The main focus of this work will be on nuclei around nobelium with 102 protons, approximately halfway between the well-studied nuclei around uranium and the frontier of superheavy elements. Here spectroscopic methods can be used to gain detailed insights into the shape of the nucleus and the b