The Muon Ionization Cooling Experiment (MICE) located at Rutherford Appleton Laboratory in the U.K. has demonstrated muon ionization beam... Show moreThe Muon Ionization Cooling Experiment (MICE) located at Rutherford Appleton Laboratory in the U.K. has demonstrated muon ionization beam cooling for the first time. A beam of muons in MICE is produced from high-energy proton beam collision with a fixed target, generating pions which in turn decay into muons. Pion-decay muons, thus, are tertiary particles and, as a result, occupy a large volume in position‒momentum phase space. To fit the muon beam into smaller and more cost-effective accelerating devices, muon beam phase‒space volume needs to be reduced (beam cooling). Ionization beam cooling, which before MICE has never been demonstrated experimentally for muons, is the only technique fast enough to be used for muons within their short lifetime. Ionization cooling occurs when muons traverse an absorbing material and lose momentum through ionization energy loss. The cooling effect in MICE is measured using two scintillating-fiber tracking detectors. These trackers, one upstream and one downstream of the absorber, reconstruct and measure the position and momentum coordinates of each muon. Given the precision MICE needed to demonstrate beam cooling, it is necessary to develop analysis tools that can account for any effects that may lead to inaccurate measurement of cooling, such as non‒linear effects in beam optics. Non‒parametric density estimation techniques, such as kernel density estimation (KDE), provide a basis for creating analysis tools that are robust against these effects, directly calculating the muon beam phase-space density and volume for demonstrating beam cooling. This thesis focuses on the application of KDE to the measurement of beam cooling in MICE. The KDE technique is validated using known distributions and is applied to simulated and experimental MICE data corresponding to the various magnet, optics, and absorber configurations. Using the KDE technique, muon beam cooling in the four‒dimensional transverse phase space, as well as reverse emittance exchange using MICE data have been demonstrated. Show less
