近日，国际介子电离冷却实验合作组（The MICE Collaboration）取得一项新进展。经过不懈努力，他们证实电离冷却降低介子束的横向发射率。相关研究成果已于2024年7月17日在国际知名学术期刊《自然—物理学》上发表。

该研究团队证明了在电离冷却实验中，电离冷却导致穿过氢化锂或液氢吸收体的μ子束的横向发射率降低。这项研究结果代表了实现介子基设施在能量和强度边界上运行的实质性进展。

据悉，加速介子束已被考虑用于下一代高能轻子-反轻子碰撞和中微子振荡的研究。然而，高亮度的μ子光束还没有被制造出来。μ子加速和存储的主要挑战来自于通过介子衰变产生μ子的机制所产生的光束所占据的大相空间体积。通过电离冷却可以减小介子束的相空间体积。

附：英文原文

Title: Transverse emittance reduction in muon beams by ionization cooling

Author: The MICE Collaboration

Issue&Volume: 2024-07-17

Abstract: Accelerated muon beams have been considered for the next-generation studies of high-energy lepton–antilepton collisions and neutrino oscillations. However, high-brightness muon beams have not yet been produced. The main challenge for muon acceleration and storage stems from the large phase-space volume occupied by the beam, derived from the production mechanism of muons through the decay of pions. The phase-space volume of the muon beam can be decreased through ionization cooling. Here we show that ionization cooling leads to a reduction in the transverse emittance of muon beams that traverse lithium hydride or liquid hydrogen absorbers in the Muon Ionization Cooling Experiment. Our results represent a substantial advance towards the realization of muon-based facilities that could operate at the energy and intensity frontiers.

DOI: 10.1038/s41567-024-02547-4

Source: https://www.nature.com/articles/s41567-024-02547-4