187 research outputs found
Characterisation of the muon beams for the Muon Ionisation Cooling Experiment
A novel single-particle technique to measure emittance has been developed and used to characterise seventeen different muon beams for the Muon Ionisation Cooling Experiment (MICE). The muon beams, whose mean momenta vary from 171 to 281 MeV/c, have emittances of approximately 1.2â2.3 Ïâmm-rad horizontally and 0.6â1.0 Ïâmm-rad vertically, a horizontal dispersion of 90â190 mm and momentum spreads of about 25 MeV/c. There is reasonable agreement between the measured parameters of the beams and the results of simulations. The beams are found to meet the requirements of MICE
Transverse Emittance Reduction in Muon Beams by Ionization Cooling
Accelerated muon beams have been considered for 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 muon production mechanism through the decay of
pions from proton collisions. Ionization cooling is the technique proposed to
decrease the muon beam phase-space volume. Here we demonstrate a clear signal
of ionization cooling through the observation of transverse emittance reduction
in beams that traverse lithium hydride or liquid hydrogen absorbers in the Muon
Ionization Cooling Experiment (MICE). The measurement is well reproduced by the
simulation of the experiment and the theoretical model. The results shown here
represent a substantial advance towards the realization of muon-based
facilities that could operate at the energy and intensity frontiers.Comment: 23 pages and 5 figure
First demonstration of ionization cooling by the Muon Ionization Cooling Experiment
High-brightness muon beams of energy comparable to those produced by
state-of-the-art electron, proton and ion accelerators have yet to be realised.
Such beams have the potential to carry the search for new phenomena in
lepton-antilepton collisions to extremely high energy and also to provide
uniquely well-characterised neutrino beams. A muon beam may be created through
the decay of pions produced in the interaction of a proton beam with a target.
To produce a high-brightness beam from such a source requires that the phase
space volume occupied by the muons be reduced (cooled). Ionization cooling is
the novel technique by which it is proposed to cool the beam. The Muon
Ionization Cooling Experiment collaboration has constructed a section of an
ionization cooling cell and used it to provide the first demonstration of
ionization cooling. We present these ground-breaking measurements.Comment: 19 pages and 6 figure
Demonstration of cooling by the Muon Ionization Cooling Experiment
The use of accelerated beams of electrons, protons or ions has furthered the development of nearly every scientific discipline. However, high-energy muon beams of equivalent quality have not yet been delivered. Muon beams can be created through the decay of pions produced by the interaction of a proton beam with a target. Such âtertiaryâ beams have much lower brightness than those created by accelerating electrons, protons or ions. High-brightness muon beams comparable to those produced by state-of-the-art electron, proton and ion accelerators could facilitate the study of leptonâantilepton collisions at extremely high energies and provide well characterized neutrino beams1,2,3,4,5,6. Such muon beams could be realized using ionization cooling, which has been proposed to increase muon-beam brightness7,8. Here we report the realization of ionization cooling, which was confirmed by the observation of an increased number of low-amplitude muons after passage of the muon beam through an absorber, as well as an increase in the corresponding phase-space density. The simulated performance of the ionization cooling system is consistent with the measured data, validating designs of the ionization cooling channel in which the cooling process is repeated to produce a substantial cooling effect9,10,11. The results presented here are an important step towards achieving the muon-beam quality required to search for phenomena at energy scales beyond the reach of the Large Hadron Collider at a facility of equivalent or reduced footprint6
Electron-muon ranger: performance in the MICE muon beam
The Muon Ionization Cooling Experiment (MICE) will perform a detailed study of ionization cooling to evaluate the feasibility of the technique. To carry out this program, MICE requires an efficient particle-identification (PID) system to identify muons. The Electron-Muon Ranger (EMR) is a fully-active tracking-calorimeter that forms part of the PID system and tags muons that traverse the cooling channel without decaying. The detector is capable of identifying electrons with an efficiency of 98.6%, providing a purity for the MICE beam that exceeds 99.8%. The EMR also proved to be a powerful tool for the reconstruction of muon momenta in the range 100â280 MeV/c
Electron-muon ranger: performance in the MICE muon beam
The Muon Ionization Cooling Experiment (MICE) will perform a detailed study of ionization cooling to evaluate the feasibility of the technique. To carry out this program, MICE requires an efficient particle-identification (PID) system to identify muons. The Electron-Muon Ranger (EMR) is a fully-active tracking-calorimeter that forms part of the PID system and tags muons that traverse the cooling channel without decaying. The detector is capable of identifying electrons with an efficiency of 98.6%, providing a purity for the MICE beam that exceeds 99.8%. The EMR also proved to be a powerful tool for the reconstruction of muon momenta in the range 100â280 MeV/c
Pion contamination in the MICE muon beam
The international Muon Ionization Cooling Experiment (MICE) will perform a systematic investigation of ionization cooling with muon beams of momentum between 140 and 240\,MeV/c at the Rutherford Appleton Laboratory ISIS facility. The measurement of ionization cooling in MICE relies on the selection of a pure sample of muons that traverse the experiment. To make this selection, the MICE Muon Beam is designed to deliver a beam of muons with less than 1\% contamination. To make the final muon selection, MICE employs a particle-identification (PID) system upstream and downstream of the cooling cell. The PID system includes time-of-flight hodoscopes, threshold-Cherenkov counters and calorimetry. The upper limit for the pion contamination measured in this paper is at 90\% C.L., including systematic uncertainties. Therefore, the MICE Muon Beam is able to meet the stringent pion-contamination requirements of the study of ionization cooling.Department of Energy and National Science Foundation (U.S.A.), the Instituto Nazionale di Fisica Nucleare (Italy), the Science and Technology Facilities Council (U.K.), the European Community under the European Commission Framework Programme 7 (AIDA project, grant agreement no. 262025, TIARA project, grant agreement no. 261905, and EuCARD), the Japan Society for the Promotion of Science and the Swiss National Science Foundation, in the framework of the SCOPES programme
First demonstration of ionization cooling by the muon ionization cooling experiment
High-brightness muon beams of energy comparable to those produced by state-of-the-art electron, proton and ion accelerators have yet to be realised. Such beams have the potential to carry the search for new phenomena in lepton-antilepton collisions to extremely high energy and also to provide uniquely well-characterised neutrino beams. A muon beam may be created through the decay of pions produced in the interaction of a proton beam with a target. To produce a high-brightness beam from such a source requires that the phase space volume occupied by the muons be reduced (cooled). Ionization cooling is the novel technique by which it is proposed to cool the beam. The Muon Ionization Cooling Experiment collaboration has constructed a section of an ionization cooling cell and used it to provide the first demonstration of ionization cooling. We present these ground-breaking measurements
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