Birmingham Nuclear Physics Consolidated Grant 2023

伯明翰核物理综合赠款 2023

• 批准号: ST/Y00034X/1
• 负责人: David Evans
• 金额: $ 211.48万
• 依托单位: University of Birmingham
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FY00034X%2F1
• 关键词: Birmingham; Nuclear; Physics; Consolidated; Grant

Our proposed research has two broad themes that build upon our world leading areas of expertise. The first of these involves the study of high-energy nuclear collisions at the Large Hadron Collider, the world's highest energy particle accelerator. The aim of the ALICE experiment is to study nuclear matter, as it would have existed about a millionth of a second after the Big Bang when the Universe was so hot and so dense that nuclei did not exist. In its primordial state nuclear matter consists of its fundamental constituents (quarks and gluons) in a plasma state. We recreate this novel state of matter in our experiment and we are developing ways of studying these high-energy nuclear collisions to discover the properties of the quark-gluon plasma. This is technically challenging and the group has developed a sophisticated electronic trigger system that controls the experiment and is entirely responsible for it. The quark-gluon plasma has remarkable properties, such as an abundance of strange quarks and near-perfect fluidity. In this proposal, we are trying to determine whether size matters by finding the smallest drop of plasma that still retains these properties. We are using grazing collisions to explore the internal structure of nuclei at high energy. And we are looking at the debris of quarks and gluons that are sometimes scattered out of the collision, producing a shower of particles in our detector known as a jet, to study the conditions inside the plasma. We are also performing R&D into new detector technologies based on silicon pixel detectors in which the readout electronics is contained within the pixel.What happens in stars: the cooking pots of the Universe and how the structure of the nuclei involved in these reactions influences the formation of elements is at the centre of Theme 2's research portfolio. From red-giant stars which burn helium to some of the most explosive events known, such as X-ray bursts and supernovae - out-shining galaxies, albeit for a short time - the structure of nuclei play a pivotal role. The interplay between neutrons and protons within the nucleus can have a very significant impact on such astrophysical processes. One manifestation of the nuclear force is the observation of clustering in which protons and neutrons clump together inside larger nuclei, for example into alpha particles (two protons and two neutrons). The strong force is highly complex, which makes theoretical predictions formidable, so our research makes extremely precise measurements of how light nuclei interact. By detecting all the fragments of such collisions we can rebuild the nuclear system from which they originated to reveal detailed properties and also measure how quickly nuclei will combine together in stellar environments. These results can then be used to improve models of these colossal energy-release events taking place and that have led to the abundance of elements we find on earth. Finally, we are developing an experimental programme to exploit gamma-ray and neutron beams. Gamma rays allow the structure of nuclei to be probed with great precision through their electromagnetic properties. Conversely, uncharged neutrons are capable of transmuting elements even at low energies and reveal information about the most important matter-producing reactions in the Universe. This is possible due to Birmingham's new high-intensity neutron facility which is able to mimic what happens in the stars in our laboratory.

我们提出的研究有两个广泛的主题，建立在我们世界领先的专业领域。第一个项目是在世界上能量最高的粒子加速器——大型强子对撞机上研究高能核碰撞。ALICE实验的目的是研究核物质，因为它在大爆炸后大约百万分之一秒存在，当时宇宙非常热，密度非常大，原子核不存在。在原始状态下，核物质由处于等离子态的基本成分（夸克和胶子）组成。我们在实验中重建了这种物质的新状态，我们正在开发研究这些高能核碰撞的方法，以发现夸克-胶子等离子体的特性。这在技术上具有挑战性，该团队开发了一种复杂的电子触发系统来控制实验并对其完全负责。夸克-胶子等离子体具有显著的特性，比如大量的奇异夸克和近乎完美的流动性。在这个提议中，我们试图通过寻找仍然保留这些特性的最小的等离子体滴来确定尺寸是否重要。我们利用掠射碰撞来探索高能核的内部结构。我们正在观察夸克和胶子的碎片，它们有时会从碰撞中散射出来，在我们的探测器中产生一束粒子，也就是所谓的喷流，以研究等离子体内部的情况。我们还在研发基于硅像素探测器的新型探测器技术，其中读出电子元件包含在像素内。在恒星中发生了什么：宇宙的烹饪锅以及参与这些反应的原子核结构如何影响元素的形成是主题2的研究组合的中心。从燃烧氦的红巨星到一些已知的最具爆炸性的事件，如x射线爆发和超新星——尽管时间很短，但比星系更发光——原子核的结构起着关键作用。原子核内中子和质子之间的相互作用可以对这类天体物理过程产生非常重要的影响。核力的一种表现是观察到质子和中子在较大的原子核内聚集在一起，例如形成α粒子（两个质子和两个中子）。强作用力非常复杂，这使得理论预测变得非常困难，因此我们的研究对轻核如何相互作用进行了极其精确的测量。通过检测此类碰撞的所有碎片，我们可以重建它们起源的核系统，以揭示详细的特性，并测量原子核在恒星环境中结合的速度。这些结果可以用来改进这些巨大的能量释放事件发生的模型，这些事件导致了我们在地球上发现的丰富元素。最后，我们正在开发一个利用伽马射线和中子束的实验方案。通过伽马射线的电磁特性，可以非常精确地探测原子核的结构。相反，不带电的中子即使在低能量下也能改变元素，并揭示宇宙中最重要的物质产生反应的信息。这是可能的，因为伯明翰的新高强度中子设备能够模拟发生在我们实验室的恒星。