Imperial College of Science and Technology, Department of Physics, London, United Kingdom
DPNC, Genève, Switzerland
Belgrade Institute of Physics, Belgrade, Serbia
The Muon Ionization Cooling Experiment (MICE) collaboration will demonstrate the feasibility of ionization cooling, the technique proposed for a future muon storage ring or collider. The muon beam parameters are measured particle-by-particle, before and after a cooling cell, using high precision scintillating-fibre trackers in a solenoidal field. The position and momentum reconstruction of individual muons in MICE allows for the development of several alternative figures of merit in addition to beam emittance. Contraction of the phase-space volume occupied by the sample, or equivalently the increase in phase-space density at its core, is an unequivocal cooling signature. Single-particle amplitude, defined as a weighted distance to the sample centroid, can be used to probe the change in the density in the core of the beam. Alternatively, non-parametric statistics provides reliable methods to estimate the entire phase-space density distribution and reconstruct probability contours. The aforementioned techniques are robust to transmission losses and sample non-linearities, making them ideal candidates to perform a cooling measurement in MICE. Preliminary results are presented here.
Submitted by the MICE speakers bureau. If accepted, a member of the collaboration will be selected to present the contribution
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
The Muon Ionization Cooling Experiment (MICE) was designed to demonstrate a measurable reduction in beam emittance due to ionization cooling. The emittance of a variety of muon beams was reconstructed before and after a 'cooling cell', allowing the change in the phase-space distribution due to the presence of an absorber to be measured. The core of the MICE experiment is a cooling cell that can contain a range of solid and cryogenic absorbers inside a focussing solenoid magnet. For the data described here, a single lithium hydride (LiH) absorber was installed and two different emittance beam have been analysed. Distributions that demonstrate emittance increase and equilibrium have been reconstructed, in agreement with theoretical predictions. Data taken during 2016 and 2017 is currently being analysed to evaluate the change in emittance with a range of absorber materials, different initial emittance beams and various magnetic lattice settings. The current status and the most recent results of these analyses is presented.
Submitted by the MICE speakers bureau. If accepted, a member of the collaboration will be selected to present the contribution
University of Glasgow, Glasgow, United Kingdom
Laurentian University, Campus Sudbury, Sudbury, Ontario, Canada
Multiple coulomb scattering and energy loss are well known phenomena experienced by charged particles as they traverse a material. However, from recent measurements by the MuScat collaboration, it is known that the available simulation codes (GEANT4, for example) overestimate the scattering of muons in low Z materials. This is of particular interest to the Muon Ionization Cooling Experiment (MICE) collaboration which has the goal of measuring the reduction of the emittance of a muon beam induced by energy loss in low Z absorbers. MICE took data without magnetic field suitable for multiple scattering measurements in the fall of 2015 with the absorber vessel filled with Xenon and in the spring of 2016 using a lithium hydride absorber. The scattering data are compared with the predictions of various models, including the default GEANT4 model. In the fall of 2016 MICE took data with magnetic fields on and measured the energy loss of muons in a lithium hydride absorber. These data are also compared with model predictions and with the Bethe-Bloch formula.
Submitted by the MICE speakers bureau. If accepted, a member of the collaboration will be selected to present the contribution
Fermilab, Batavia, Illinois, USA