Normalised transverse emittance reduction via ionisation cooling in MICE ‘Flip Mode’

Low-emittance muon beams are central to the development of a Muon Collider and can significantly enhance the performance of a Neutrino Factory. The main challenge for muon acceleration stems from the large emittance with which the muon beam is produced. Maximising the muon yield while maintaining a suitably small aperture in the accelerator system requires that the muon beam emittance be reduced (cooled). The international Muon Ionisation Cooling Experiment (MICE) was designed to demonstrate the feasibility of the ionisation cooling technique, and provide the first measurement of normalised transverse emittance reduction in a muon beam. This work focuses on the emittance reduction analysis of 140 MeV/c MICE muon beams that passed through a liquid hydrogen or a lithium hydride absorber. During the acquisition of the studied data sets, the magnetic channel produced a field that flipped polarity at the absorber, to prevent a canonical angular momentum increase. A novel beam sampling procedure was developed to account for imperfections in beam matching at the entrance into the cooling channel, which improved the cooling signal measurement. A reduction in the muon beam normalised transverse emittance that grows linearly with input emittance was observed, which is a clear signal of ionisation cooling. The measurement is consistent with the simulation and the theoretical model. Furthermore, both the liquid hydrogen and the lithium hydride absorbers were found to induce a reduction in the mean canonical angular momentum of the beam. This effect can be attributed to energy loss at the absorber situated at the field polarity flip, combined with an increasing beam size across the absorber region. This result confirms that the field polarity flip at the absorber would maintain a low-magnitude canonical angular momentum within the cooling stage of a future muon facility.Open Acces

Towards a muon collider

A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work

Erratum: Towards a muon collider

The original online version of this article was revised: The additional reference [139] has been added. Tao Han’s ORICD ID has been incorrectly assigned to Chengcheng Han and Chengcheng Han’s ORCID ID to Tao Han. Yang Ma’s ORCID ID has been incorrectly assigned to Lianliang Ma, and Lianliang Ma’s ORCID ID to Yang Ma. The original article has been corrected

Towards a muon collider

A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work

Progress on Muon Ionization Cooling Demonstration with MICE

The Muon Ionization Cooling Experiment (MICE) at the Rutherford Appleton Laboratory has collected extensive data to study the ionization cooling of muons. Several million individual particle tracks have been recorded passing through a series of focusing magnets in a number of different configurations and a liquid hydrogen or lithium hydride absorber. Measurement of the tracks upstream and downstream of the absorber has shown the expected effects of 4D emittance reduction. Further studies are providing more and deeper insight

Towards a Muon Collider

International audienceA muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10~TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work

Towards a muon collider

A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work

Towards a muon collider

A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work

Towards a muon collider

A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work