Nuclear astrophysics with exotic and stable ion beams, and nuclear data evaluation

具有奇异且稳定离子束的核天体物理学以及核数据评估

• 批准号: 261753-2011
• 负责人: Chen, Alan
• 金额: $ 5.61万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Individual
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=525357
• 关键词: Nuclear; astrophysics; exotic; stable; ion

The main goals of the proposed research is to find answers to two questions that seem unrelated at first glance, but that turn out to be inextricably linked: (1) Where does everything around us come from? Or more specifically, what is the ultimate origin of the calcium in our bones, the oxygen in the air we breathe, and the rest? And secondly: (2) Why is the sun "warm?" Or more generally, what makes stars shine? Nature, cleverly, does the second by doing the first: The origin of the energy that powers stars like our sun is from nuclear reactions happening in their cores, which, throughout the star's lifetime, also make heavier elements out of lighter ones. When the star "dies," these new elements are ejected into space, sometimes gently, but sometimes violently ("supernova"). Out of these elements, new stars and planets are born, leading ultimately to human beings on Earth - we are literally made of stardust (or, less poetically, of nuclear waste!). My research aims to explore the implications of this general paradigm by studying the stellar nuclear reactions in terrestrial laboratories. I use "particle accelerators" to produce beams of ions that are then collided with a "target," in order to reproduce the reactions happening in stars. I then use "detectors" to measure the properties of the reaction products, which allow us to determine detailed information about the reaction and how quickly/slowly it goes. These "reaction rates" are then put back into computer models of stars, which explore their implications for the energy generation and element synthesis. In recent years, we have focussed on stellar explosions like supernovae, novae, and x-ray bursts. Since these stars are very hot, the critical nuclear reactions often involve unstable, exotic elements instead of the garden-variety stable ones. This poses a challenge for our experiments because beams of unstable ions are challenging to produce. In recent years, new facilities with this capability have been built, and we have been working at such labs in Canada, USA, Germany and Japan. Through our research, we will gain a clearer understanding of our shared cosmic heritage with the stars - and ensure that Canada will contribute strongly to this exciting, interdisciplinary puzzle.

这项研究的主要目标是找到两个问题的答案，这两个问题乍一看似乎无关，但结果却密不可分：（1）我们周围的一切都来自哪里？ 或者更具体地说，我们骨骼中的钙、我们呼吸的空气中的氧气以及其他物质的最终来源是什么？ 第二：（2）为什么太阳是“温暖的”？“或者更一般地说，是什么让星星发光？ 大自然很聪明，通过做第一件事来做第二件事：像我们的太阳这样的恒星的能量来源于它们核心中发生的核反应，在星星的一生中，这些反应也会从较轻的元素中产生较重的元素。 当星星“死亡”时，这些新的元素被喷射到太空中，有时温和，但有时猛烈（“超新星”）。 从这些元素中，新的恒星和行星诞生了，最终导致地球上的人类-我们实际上是由星尘（或者，不那么诗意，核废料！） 我的研究旨在通过研究地球实验室中的恒星核反应来探索这一一般范式的含义。 我使用“粒子加速器”来产生离子束，然后与“目标”相撞，以再现恒星中发生的反应。 然后，我使用“探测器”来测量反应产物的性质，这使我们能够确定有关反应的详细信息以及反应进行的速度/速度。 这些“反应速率”然后被放回恒星的计算机模型中，探索它们对能量产生和元素合成的影响。 近年来，我们一直专注于恒星爆炸，如超新星，新星和x射线爆发。由于这些恒星非常热，临界核反应通常涉及不稳定的外来元素，而不是普通的稳定元素。 这对我们的实验提出了挑战，因为不稳定离子束的产生具有挑战性。 近年来，具有这种能力的新设施已经建成，我们一直在加拿大，美国，德国和日本的此类实验室工作。 通过我们的研究，我们将更清楚地了解我们与恒星共享的宇宙遗产，并确保加拿大将为这一令人兴奋的跨学科难题做出巨大贡献。