Strip Scintillator Array with ultra-FAst timing for Rare Isotope study (SAFARI)

原子核，所有可见物质的核心，体现了自然界强大力量的美丽，它将构建模块，质子和各种复杂的身体系统结合在一起。地球上自然存在的大多数长寿命原子核，其中子与质子的比例接近平衡。具有大的中子与质子不对称性的稀有同位素是在自然界中一些最奇异的环境中产生的，这些环境富含中子，如中子星和超新星，或者富含质子，如中子星星表面的吸积盘。因此，这些富含中子或质子的同位素在我们面前展示了大量关于自然界如何组织这些系统及其在创造我们周围大多数重元素中的作用的基本知识。这种元素合成的特征最近在自然界最具灾难性的事件之一--两颗中子星的合并中被发现。该提案旨在开发超快定时塑料闪烁体阵列，这对于识别我们实验室中产生的稀有同位素是必要的。它们的生产是通过核反应进行的，例如在世界上少数几个专门的加速器设施中的碎裂或裂变，其中德国的GSI设施提供最高能量的稀有同位素束。利用相对论稀有同位素束，我们的目标是解开如何中子分布在这样的np不对称条件。这为描述我们宇宙中富含中子的环境的行为提供了指导。这也带来了关于核（强）力的新信息，以及它如何控制稀有同位素的排列，即壳结构和性质。这些同位素的性质决定了它们的反应和衰变如何驱动自然界中大多数重元素的产生。

Nuclei, the core of all visible matter, embody the beauty of nature's strong force binding the building blocks, protons and into a wide variety of complex many body systems. Most of the long--lived nuclei occurring naturally on earth have a nearly balanced ratio of neutrons to protons. Rare isotopes with a large neutron to proton asymmetry are created in some of nature's most exotic environments that are rich in neutrons, such as neutron stars and supernovae, or rich in protons, such a accretion disks on the surface of a neutron star. These neutron--rich or proton--rich isotopes therefore, open before us a wealth of new knowledge on the fundamentals of how nature organizes such systems and their role in creation of majority of the heavy elements around us. Signature of such element synthesis was recently seen in one of nature's most cataclysmic events, in the merger of two neutron stars. This proposal aims to develop ultra-fast-timing plastic scintillator arrays that are necessary to identify the rare isotopes produced in our laboratories. Their production takes place with nuclear reactions, such as fragmentation or fission in a few specialized accelerator facilities in the world among which the facility at GSI in Germany provides highest energy beams of the rare isotopes. Using the relativistic rare isotope beams we aim to unravel how the neutrons are distributed in such np asymmetric conditions. This provides guidance to characterize the behavior of neutron--rich environments of our Universe. This also brings new information on the nuclear (strong) force and how that governs the arrangement, i.e. shell structure, and properties of the rare isotopes. The properties of these isotopes determine how their reactions and decays drive the creation of most of the heavy elements in nature.