MRI: Development of a Superconducting Magnet Coil and a 201 MHz RF Cavity for Testing Muon Ionization Cooling Techniques

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This proposal is for instrumentation development needed to test techniques to advance the Muon Ionization Cooling Experiment (MICE). In the field of particle physics, there is increasing interest in using particle accelerators to form very intense beams of high-energy muons. Discovered in 1937, the muon, a more massive cousin of the electron, is a subatomic particle, whose simple and well-understood interactions with matter make it a useful probe for a range of purposes. Until now, however, due to its short average lifetime of 2.2 microseconds, it has not been possible to accelerate muons. The key step in demonstrating the feasibility of muon accelerators is the Muon Ionization Cooling Experiment (MICE). The main obstacle to accelerating an intense muon beam is that such beams are created too large to fit into the typical vacuum chamber of a synchrotron and the short muon lifetime leaves little time to adequately shrink and accelerate the beam. Ionization cooling is a new technique to shrink, or cool a muon beam quickly. In this process, a beam of muons passes through selected material in which it loses energy by ionizing nearby atoms. These interactions reduce all three components of a muons velocity: horizontal, vertical, and longitudinal. The muon beam is then accelerated by radio-frequency cavities, replacing only the longitudinal velocity component of the muons. As the horizontal and vertical components are increasingly reduced while the longitudinal component is maintained, the muons trajectories become more nearly parallel, allowing focusing magnets to substantially reduce the size of the beam.The broader impacts of this proposal includes University of Mississippi students and local QuarkNet teachers who will be involved and will use acoustic sensors to locate and characterize sparking (electrical breakdown) in the RF cavity. Development of muon cooling could lead to building a neutrino factory and discovering CP violation in the lepton sector. Lepton CP violation may quite possibly cause the baryon-antibaryon asymmetry in the universe. A neutrino beam from a Neutrino Factory might be aimed at a detector in the National Science Foundation Deep Underground Science and Engineering Laboratory (DUSEL). This would give the United States a first rate physics project for understanding the universe and for training students.