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Muon Ionisation Cooling Experiment

μ子电离冷却实验

基本信息

批准号：
2011378
负责人：
金额：
--
依托单位：
Brunel University London
依托单位国家：
英国
项目类别：
Studentship
财政年份：
2018
资助国家：
英国
起止时间：
2018 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=studentship-2011378
关键词：
Muon Ionisation Cooling Experiment

项目摘要

The Muon Ionisation Cooling Experiment (MICE) is trying to demonstrate ionisation cooling, that is a reduction in the emittance of a charged particle beam. The emittance is the volume occupied by a beam in position and momentum phase space. During ionisation cooling the charged particle beam is passed through a series of absorbers and radio-frequency (RF) cavities. The absorbers, such as liquid Hydrogen or Lithium Hydride, reduce the overall momentum of the particles, while the RF cavities reaccelerate the particles along the axis of the direction of motion of the beam. This process replenishes the longitudinal momentum of the beam but reduces the transverse momentum. Thus, the emittance of the beam has been reduced.One of the main motivations behind ionisation cooling is the possibility of future neutrino experiments to analyse neutrino oscillations, neutrino masses and the mass hierarchy and whether the neutrino is a Majorana particle.To create a muon beam of sufficient intensity for neutrino factory detectors requires a muon beam of sufficient density. However, the muon beam has an incredibly short lifetime (2.2s). The muon beam is created from the decay of a highly dispersed pion beam. The pion beam is highly dispersed as it has been created from the bombardment of a proton beam against a target. Current confinement techniques are not able to create muon beams of sufficient density within the lifetime of the muon; however, ionisation cooling would allow for this.MICE uses a number of detectors to identify the particles travelling in the experiment (pions, muons, electrons) such as Time-of-Flight systems, Cherenkov counters, Kloe Light and an electron Muon Ranger. The effectiveness of the Particle Identification system will be looked at in this project.MICE also uses two solenoidal spectrometers, each having five scintillating fibre stations which contain the particle beam and track the motion of the particles travelling through it. The results from the various experiments carried out need to be extensively analysed to determine the effectiveness of ionisation cooling and to what accuracy. For example, the emittancegrowth due to optical aberrations (e.g spherical, chromatic) in the magnets will be explored during this project.

μ子电离冷却实验（MICE）试图证明电离冷却，即带电粒子束发射率的降低。发射度是光束在位置和动量相空间中所占据的体积。在电离冷却期间，带电粒子束通过一系列吸收器和射频（RF）腔。吸收体（例如液态氢或氢化锂）减小粒子的总动量，而RF腔沿着射束的运动方向的轴重新加速粒子。这一过程减小了光束的纵向动量，但减小了横向动量。电离冷却背后的主要动机之一是未来中微子实验的可能性，以分析中微子振荡，中微子质量和质量等级以及中微子是否是马约拉纳粒子。为了制造足够强度的μ子束用于中微子工厂探测器，需要足够密度的μ子束。然而，μ子束的寿命非常短（2.2s）。μ介子束是由高度分散的π介子束衰变产生的。π介子束是高度分散的，因为它是由质子束轰击靶而产生的。目前的限制技术无法在μ子的寿命内产生足够密度的μ子束;然而，电离冷却将允许这一点。MICE使用许多探测器来识别实验中移动的粒子（π子，μ子，电子），如飞行时间系统，切伦科夫计数器，Kombi-Light和电子μ子Ranger。该项目将研究粒子识别系统的有效性。MICE还使用两台螺线管光谱仪，每台都有五个光纤站，包含粒子束并跟踪粒子在其中的运动。需要对各种实验的结果进行广泛分析，以确定电离冷却的有效性和准确性。例如，在这个项目中，将探讨由于磁体中的光学像差（如球面像差、色差）引起的发射度增长。