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| MOPAN117 | Magnet System for Helical Muon Cooling Channels | 443 |
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Funding: Supported in part by STTR Grant DE-FG02-04ER86191. A helical cooling channel consisting of a pressurized gas absorber imbedded in a magnetic channel that provides superimposed solenoidal, helical dipole and helical quadrupole fields has shown considerable promise in providing six-dimensional cooling of muon beams. The analysis of this muon cooling technique with both analytic and simulation studies has shown significant reduction of muon phase space. A particular channel that has been simulated is divided into four segments each with progressively stronger fields and smaller apertures to reduce the equilibrium emittance so that more cooling can occur. The fields in the helical channel are sufficiently large that the conductor for segments 1 and 2 can be Nb3Sn and the conductor for segments 3 and 4 may need to be high temperature superconductor. This paper will describe the magnetic specifications for the channel and two conceptual designs on how to implement the magnetic channel. |
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| MOPAS012 | Magnets for the MANX 6-D Muon Cooling Demonstration Experiment | 461 |
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Funding: Supported in part by DOE STTR grant DE-FG02-04ER86191 MANX is a 6-dimensional muon ionization-cooling experiment that has been proposed to Fermilab to demonstrate the use of a Helical Cooling Channel (HCC) for future muon colliders and neutrino factories. The HCC for MANX has solenoidal, helical dipole, and helical quadrupole magnetic components which diminish as the beam loses energy as it slows down in a liquid helium absorber inside the magnets. Two superconducting magnet system designs are described which use quite different approaches to providing the needed fields. Additional magnets that provide emittance matching between the HCC and upstream and downstream spectrometers are also described as are the results of G4Beamline simulations of the beam cooling behaviour of the complete magnet and absorber system. |
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| MOPAS013 | Design Study of a 2-in-1 Large-aperture IR Dipole (D2) for the LHC Luminosity Upgrade | 464 |
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Funding: This work was supported by the U. S. Department of Energy. After LHC operates for several years at nominal parameters it will need an upgrade to higher luminosity. Replacing the low-beta insertions with a higher performance design based on advanced superconducting magnets is a straightforward step in this direction. One of the approaches being considered for the new LHC IRs is a "dipole-first: option with two separation dipoles placed in front of the focusing quadrupoles. It reduces the number of parasitic collisions with respect to the "quadrupole-first" option and allows independent field error corrections for each beam. Most of key magnet designs for the "dipole-first" option including high-field large-aperture dipoles (D1) and 2-in-1 quadrupoles have already been studied and reported. This paper focuses on design studies of the 2-in-1 separation dipole (D2) located between D1 and the quadrupoles. High operation field of the same polarity in large adjacent apertures imposes limitations on the maximum field, field quality and mechanics for this magnet. This paper analyses possible D2 magnet designs based on Nb3Sn superconductor and compares them in terms of the aperture size, maximum field, field quality and Lorents forces in the coil. |
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| MOPAS019 | Focusing Solenoid for the Front End of a Linear RF Accelerator | 473 |
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| Following a design study, a prototype of a focusing solenoid for use in a superconducting RF linac has been built and is being tested at FNAL. The solenoid cold mass is comprised of the main coil, two bucking coils, and a soft steel flux return. It is mounted inside a dedicated cryostat with a 20 mm diameter warm bore. At the maximum current of 250 A, the magnetic field reaches 7.2 T in the center of the solenoid and is less than 0.01 T at a distance of 200 mm from the center. The flange-to-flange length of the system is 270 mm. This report discusses the main design features of the solenoid and first test results. | ||
| MOPAS023 | Nb3Sn Accelerator Magnet Technology R&D at Fermilab | 482 |
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Funding: This work was supported by the U. S. Department of Energy Accelerator magnets based on Nb3Sn superconductor advances magnet operation fields above 10T and increases the coil temperature margin. Development of a new accelerator magnet technology includes the demonstration of main magnet parameters (maximum field, quench performance, field quality, etc.) and their reproducibility using short models, and then the demonstration of technology scale up using long coils. Fermilab is working on the development of Nb3Sn accelerator magnets using shell-type dipole coils and react-and-wind method. As a part of the first phase of technology development Fermilab built and tested six 1-m long dipole models and several dipole mirror configurations. The last three dipoles and two mirrors reached their design fields of 10-11 T. Reproducibility of magnet field quality was demonstrated by all six short models. The technology scale up phase has started by building 2m and 4m dipole coils and testing them in a mirror configuration. This effort complements the Nb3Sn scale up work being performed in the framework of US LHC Accelerator Research Program (LARP). The status and main results of the Nb3Sn accelerator magnet development at Fermilab are reported. |
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| MOPAS027 | Energy Deposition Studies of Block-Coil Quadrupoles for the LHC Luminosity Upgrade | 491 |
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Funding: Work supported by the Director, Office of Science, U. S. Department of Energy under Contract DE-AC02-05CH11231. At the LHC upgrade luminosity of 1035 cm-2 s-1, collision product power in excess of a kW is deposited in the inner triplet quadrupoles. The quadrupole field sweeps secondary particles from pp-collisions into the superconducting coils, concentrating the power deposition at the magnetic mid-planes. The local peak power density can substantially exceed the conductor quench limits and reduce component lifetime. Under these conditions, block-coil geometries may result in overall improved performance by removing the superconductor from the magnetic mid-planes and/or allowing increased shielding at such locations. First realistic energy deposition simulations are performed for an interaction region based on block-coil quadrupoles with parameters suitable for the LHC upgrade. Results are presented on 3-D distributions of power density and accumulated dose in the inner triplet components as well as on dynamic heat loads on the cryogenic system. Optimization studies are performed on configuration and parameters of the beam pipe, cold bore and cooling channels. The feasibility of the proposed design is discussed. |