Support for U.S. Consortium on MICE: The International Muon Ionization Cooling Experiment

支持美国 MICE 联盟：国际 μ 子电离冷却实验

• 批准号: 0301737
• 负责人: Daniel Kaplan
• 金额: --
• 依托单位: Illinois Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-01 至 2009-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0301737&HistoricalAwards=false
• 关键词: Support; U.S.; Consortium; MICE; International

This proposal requests support for a U.S. university-based contribution to the Muon Ionization Cooling Experiment (MICE) being carried out at the Rutherford Appleton Laboratory (RAL) in the U.K. Recent discoveries in the study of neutrinos suggest that a very intense neutrino source, or "Neutrino Factory," might answer fundamental questions of particle physics and cosmology. This large future scientific project could be sited at an existing U.S. laboratory. MICE is an essential step towards this goal and will validate Neutrino Factory cost estimates by confirming the feasibility and performance of the key "muon cooling" technique. Neutrinos were originally postulated as massless neutral particles emitted during beta decay of radioactive nuclei. When they were found to come in two (and, later, three) types, each type was assumed (based on observation) to be immutable. However, recent experimental results indicate that over sufficiently long distances, neutrinos oscillate from one kind into another. From this, it follows that neutrinos have nonzero masses. This discovery raises fundamental issues regarding the total amount of matter in the universe and the origin of the excess of matter over antimatter, and places a high priority on studies to deduce the parameters of neutrino oscillation, including possible Charge conjugation-Parity (CP) violation in neutrino mixing. Although neutrino-oscillation studies using accelerator-derived neutrino beams are now planned or under way, recent world-wide R&D work points to a Neutrino Factory, producing a novel neutrino beam via decay of an intense muon beam circulating in a storage ring, as the ideal tool for neutrino oscillation and CP-violation studies. Such a tool would permit sensitivity several orders of magnitude beyond that of current and planned experiments. A Neutrino Factory would also be the first step towards muon-muon colliders in the longer term, with unique potential for studies of lepton collisions at the postulated Higgs resonance and the energy frontier. Muon beams at the required intensity can only be produced into a large phase space, but affordable existing acceleration technologies require a small input beam. This mismatch could be alleviated by "cooling" the muon beam to reduce its size. This is the goal of MICE and an international collaboration has been organized to carry it out. Broader impacts of this research include validation of an important new technique applicable in a variety of scientific and technological areas, including particle physics and cosmology; development of next-generation instrumentation; collaboration of interdisciplinary and international university and national-laboratory groups including accelerator and particle physicists and engineers; training of graduate and undergraduate students including those from community colleges and underrepresented minorities; and wide information dissemination via outreach activities and public media.

该提案要求支持美国大学对μ子电离冷却实验（MICE）的贡献，该实验正在英国卢瑟福阿普尔顿实验室（RAL）进行。最近在中微子研究中的发现表明，一个非常强烈的中微子源，或“中微子工厂”，可能会回答粒子物理学和宇宙学的基本问题。这个未来的大型科学项目可以在现有的美国实验室进行。MICE是实现这一目标的重要一步，并将通过确认关键的“μ子冷却”技术的可行性和性能来验证中微子工厂的成本估算。中微子最初被假定为在放射性原子核衰变过程中释放的无质量中性粒子。当发现它们有两种（后来是三种）类型时，假设每种类型（基于观察）都是不可变的。然而，最近的实验结果表明，在足够长的距离上，中微子会从一种振荡到另一种。由此可以得出，中微子具有非零质量。这一发现提出了关于宇宙中物质总量和物质超过反物质的起源的基本问题，并高度重视推导中微子振荡参数的研究，包括中微子混合中可能的电荷共轭-宇称（CP）违反。尽管使用加速器衍生的中微子束进行中微子振荡研究现在正在计划或进行中，但最近世界范围内的研发工作指向中微子工厂，通过在存储环中循环的强介子束的衰变产生一种新的中微子束，作为中微子振荡和cpp违反研究的理想工具。这种工具的灵敏度将比目前和计划中的实验高出几个数量级。从长远来看，中微子工厂也将是迈向μ - μ对撞机的第一步，在假设的希格斯共振和能量前沿研究轻子碰撞方面具有独特的潜力。所需强度的μ子光束只能产生在一个大的相空间中，但现有的可负担的加速技术需要一个小的输入光束。这种不匹配可以通过“冷却”μ子束来减小其尺寸来缓解。这是国际会展的目标，并组织了国际合作来实现这一目标。这项研究的广泛影响包括验证一项重要的新技术，该技术适用于各种科学和技术领域，包括粒子物理学和宇宙学；新一代仪器仪表的开发；跨学科和国际大学和国家实验室团体的合作，包括加速器和粒子物理学家和工程师；培训研究生和本科生，包括来自社区学院和代表性不足的少数民族的学生；通过外联活动和公共媒体广泛传播信息。