| Paper | Title | Page |
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| MOPEB061 | Fabrication, Testing and Modeling of the MICE Superconducting Spectrometer Solenoids | 409 |
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The Muon Ionization Cooling Experiment (MICE), an international collaboration sited at Rutherford Appleton Laboratory (RAL) in the UK, will demonstrate ionization cooling in a section of a realistic cooling channel using a muon beam. A five-coil superconducting spectrometer solenoid magnet will provide a 4 tesla uniform field region at each end of the cooling channel. Scintillating fiber trackers within the 400 mm diameter magnet bore tubes measure the emittance of the beam as it enters and exits the cooling channel. Each of the identical 3 meter long magnets incorporates a three-coil spectrometer magnet section and a two-coil section that matches the solenoid uniform field into the MICE cooling channel. The cold mass, radiation shield and leads are kept cold by means of three two-stage cryocoolers and one single-stage cryocooler. After incorporating several design changes to improve the magnet cooling and reliability, the fabrication and acceptance testing of the spectrometer solenoids has been completed. The key features of the spectrometer solenoid magnets are presented along with the details of a finite element model used to predict the thermal performance of the magnets. |
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| MOPEB060 | Lessons Learned for the MICE Coupling Solenoid from the MICE Spectrometer Solenoids | 406 |
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Tests of the spectrometer solenoids have taught us some important lessons. The spectrometer magnet lessons learned fall into two broad categories that involve the two stages of the coolers that are used to cool the magnets. On the first spectrometer magnet, the problems were centered on the connection of the cooler 2nd-stage to the magnet cold mass. On the second spectrometer magnet, the problems were centered on the cooler 1st-stage temperature and the connections between leads, the cold mass support intercept, and the shields to the cooler first-stage. If the cooler 1st-stage temperature is too high, the refrigerator will not produce full 2nd stage cooling. If the 1st-stage temperature is too high, the temperature of the top of the HTS leads. As a result, more heat goes into the 4 K cold mass and the temperature margin of the top of the HTS leads is too small, which are in a magnetic field. The parameters that affect the magnet cooling are compared for the MICE coupling magnet and the spectrometer magnet. |
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| WEPE050 | Alternative Muon Front-end for the International Design Study (IDS) | 3455 |
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We discuss alternative designs of the muon capture front end of the Neutrino Factory International Design Study (IDS). In the front end, a proton bunch on a target creates secondary pions that drift into a capture channel, decaying into muons. A sequence of RF cavities forms the resulting muon beams into strings of bunches of differing energies, aligns the bunches to (nearly) equal central energies, and initiates ionization cooling. This design is affected by limitations on accelerating gradients within magnetic fields. The effects of gradient limitations are explored, and mitigation strategies are presented. |
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| WEPE065 | The US Muon Accelerator Program | 3491 |
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An accelerator complex that can produce ultra-intense beams of muons presents many opportunities to explore new physics. A facility of this type is unique in that, in a relatively straightforward way, it can present a physics program that can be staged and thus move forward incrementally, addressing exciting new physics at each step. At the request of the US Department of Energy's Office of High Energy Physics, the Neutrino Factory and Muon Collider Collaboration and the Fermilab Muon Collider Task Force have recently submitted a proposal to create a Muon Accelerator Program that will have, as a primary goal, to deliver a Design Feasibility Study for an energy-frontier Muon Collider after a 7 year R&D program. This paper presents a description of a Muon Collider facility with a brief physics motivation, gives an overview of the proposal with respect to its organization and timeline and then discusses in some detail its major technical components. |
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| WEPE074 | A Possible Hybrid Cooling Channel for a Neutrino Factory | 3515 |
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A Neutrino Factory requires an intense and highly cooled (in transverse phase space) muon beam. We discuss a hybrid approach for a linear 4D cooling channel consisting of high-pressure gas-filled RF cavities –potentially allowing high gradients without breakdowns– and discrete LiH absorbers to provide the necessary energy loss that results in the needed muon beam cooling. We report simulations of the channel performance and its comparison with the vacuum case; we also discuss the various technical and safety issues associated with cavities filled with high-pressure hydrogen gas. Even with additional windows that might be needed for safety reasons, the channel performance is comparable to that of the original, all-vacuum Feasibility Study 2a channel on which our design is based. If tests demonstrate that the gas-filled RF cavities can operate properly with an intense beam of ionizing particles passing through them, our approach would be an attractive way of avoiding possible breakdown problems with a vacuum RF channel. |
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| THPEA049 | Normal Conducting RF Cavity for MICE | 3786 |
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Normal conducting RF cavities must be used for the cooling section of international Muon Ionization Cooling Experiment (MICE) which is currently under construction at Rutherford Appleton Laboratory (RAL) in UK. Eight 201-MHz cavities are needed for the MICE cooling section; fabrication of the first five cavities is nearly complete. This paper reports the cavity fabrication status that includes the cavity design, fabrication techniques and preliminary low power RF measurements of the first five cavities. |