IRIS : Charged particle reaction spectroscopy at ISAC

我们宇宙的很大一部分是由核反应提供动力的，这是太阳和星星发光背后的秘密。在我们的实验室里，核反应和散射是揭开宇宙可见物质核心秘密的方法。该项目的重点是探索远离稳定谷的短寿命稀有同位素，这些同位素的结合力很弱，其中许多同位素的中子比质子多得多，反之亦然。它们中的许多是在我们宇宙的某些环境中产生的，比如超新星，中子星。 利用世界上罕见的同位素设施，对它们的未知性质的新发现成为可能。其中包括位于加拿大粒子加速器中心TRIUMF的ISAC/ARIEL设施，该设施可以产生低能量的稀有同位素再加速束。IRIS反应光谱设施利用这些再加速的稀有同位素束来揭示稀有同位素的新特征。IRIS率先使用固体氢的薄冷冻片作为反应目标。靶的氢同位素与TRIUMF产生的稀有同位素加速束相互作用。通过使用硅条探测器和闪烁器观察这种相互作用过程中发射的粒子，我们可以窥探稀有同位素的性质。这揭示了大自然如何安排构建这些同位素的积木，从而推导出自然界最强力（核力）的性质。这也使我们能够解开大自然如何创造我们在地球上发现的大多数重元素。这些不稳定核的意外特性使得有必要寻求基本问题的答案，即自然界如何组织中子和质子以形成具有高度不对称的中子质子比的束缚系统，以及当它们变得不束缚时它们如何在极限处表现。

A large part of our universe is powered by nuclear reactions, that are the secret behind the glow of the sun and the shine of the stars. In our laboratories nuclear reactions and scattering are the ways to uncover the secrets that lie in the heart of visible matter in our universe. This project focuses on exploring the short-lived rare isotopes that are weakly bound located far from the valley of stability and many of which have a large excess of neutrons over protons or vice versa. Many of them are created in certain environments of our universe such as supernovae, neutron stars. New discoveries about their unknown properties become possible using rare isotope facilities in the world. Among them is the ISAC/ARIEL facility at Canada's particle accelerator center, TRIUMF that can produce low-energy re-accelerated beams of rare isotopes. The IRIS reaction spectroscopy facility utilizes these re-accelerated rare isotope beams to uncover new features of rare isotopes. IRIS has pioneered in the use of an thin frozen sheet of solid hydrogen as reaction target. The hydrogen isotope of the target interacts with accelerated beams of rare isotopes produced at TRIUMF. By observing the particles emitted from this interaction process using the silicon strip detectors and scintillators we can get a peek into the properties of rare isotopes. This reveals how nature arranges the building blocks to build these isotopes and hence deduce the properties of nature's strongest force (nuclear force). This also allows us to unravel how nature creates the majority of the heavy elements that we find on earth. The unexpected characteristics of these unstable nuclei make it necessary to seek answers to the fundamental question on how nature organizes the neutrons and protons to form a bound systems with highly asymmetric neutron to proton ratio and how do they behave at the limit when they become unbound.