AI 中文总结
本文综述了μ子束冷却与慢化技术，包括电离冷却、慢化、摩擦冷却及激光电离等方法，旨在克服μ子寿命短导致的束流质量限制，为下一代μ子设施和精密实验提供途径。
AI 中文摘要
μ子束是广泛应用的不可或缺工具，例如用于寻找稀有μ子衰变和μ子谱学。然而，由π介子衰变产生的常规μ子束具有大的发射度和宽的动量分布。由于μ子平均寿命为2.2 μs，常规束流冷却技术无法显著提高束流质量。这促使了专门用于μ子束冷却和慢化方法的发展。本综述调研了主要方法，包括用于高亮度μ子束的电离冷却、用于产生慢μ子的低能μ子慢化和摩擦冷却，以及用于超低发射度μ子源的热μ子素激光电离。还讨论了产生慢负μ子所面临的挑战以及基于回旋加速器捕获和μ子催化聚变的新兴概念。这些互补技术为下一代μ子设施和精密实验提供了有前景的途径。
英文摘要
Muon beams are essential tools for a wide range of applications such as the search for rare muon decays and muon spectroscopy. However, conventional muon beams produced from pion decay have large emittance and broad momentum spread. Conventional beam-cooling techniques cannot improve the beam quality significantly owing to the 2.2 $μ$s muon mean lifetime. This has motivated the development of dedicated muon beam cooling and moderation methods. This review surveys the principal approaches, including ionisation cooling for high-brightness muon beams, low-energy muon moderation and frictional cooling for slow muon production, and laser ionisation of thermal muonium for ultra-low-emittance muon sources. The challenges associated with producing slow negative muons and emerging concepts based on cyclotron trapping and muon-catalysed fusion are also discussed. These complementary techniques offer promising pathways towards next-generation muon facilities and precision experiments.
CommentsReview article prepared for ICFA Beam Dynamics Newsletter #86; to be submitted to JINST
