Fermilab, Batavia, USA
CERN, Geneva, Switzerland
The planned upgrade of the LHC collimation system includes two additional collimators to be installed in the dispersion suppressor areas of points 2, 3 and 7. The necessary longitudinal space for the collimators could be provided by replacing some 8.33 T NbTi LHC main dipoles with 11 T dipoles based on Nb3Sn superconductor and compatible with the LHC lattice and main systems. To demonstrate t his possibility Fermilab and CERN have started in 2011 a joint R&D program with the goal of building by 2014 a 5.5-m long twin-aperture dipole prototype suitable for installation in the LHC. The first step of this program is the development of a 2-m long single-aperture demonstration dipole with the nominal field of 11 T at the LHC nominal current of ~11.85 kA and 60 mm bore with ~20% margin. This paper describes the design, construction and test results of the single-aperture Nb3Sn demonstrator model for the LHC collimation system upgrade.
Fermilab, Batavia, USA
A series of accelerator quality Nb3Sn quadrupole models has been developed, fabricated and tested at Fermilab. The magnet design includes a 90 mm aperture surrounded by four two-layer Nb3Sn coils supported by a stainless steel collar, iron yoke and stainless steel skin. This paper describes the design and fabrication features of the quadrupole models and presents the summary of model tests including quench performance and field quality at 4.5 and 1.9 K.
Fermilab, Batavia, USA
The updated IR optics and conceptual designs of large aperture superconducting quadrupole magnets for a muon collider with a c.o.m. energy of 3 TeV and an average luminosity of 4·1034 cm-2 s-1 are presented. All magnets are based on the Nb3Sn superconductor and designed to provide an adequate operation field gradient in the given aperture with the critical current margin required for reliable machine operation. Special dipole coils were added to quadrupole designs to provide ~2 T bending field and thus facilitate chromaticity correction and dilute decay electron fluxes on the detector. Magnet cross-sections were optimized to achieve the best possible field quality in the magnet aperture occupied with beams. Magnet parameters are reported and compared with the requirements. Energy deposition calculations with the MARS code have allowed to optimize parameters of inner absorbers, collimators in interconnect regions and Machine-Detector Interface.
Fermilab, Batavia, USA
A new storage ring lattice based on combined function high-field magnets and conceptual designs of superconducting magnets with dipole and quadrupole coils for a muon collider with a c.o.m. energy of 3 TeV and an average luminosity of 4x1034 cm-2 s-1 are presented. Magnets are designed to provide the required focusing field gradient and bending field in the aperture with the appropriate operation margin. Magnets have large apertures to provide an adequate space for internal absorbers, vacuum insulation, beam pipe, and helium channel. Coil cross-sections were optimized to achieve the best possible field quality in the magnet aperture occupied with beams. Magnet parameters are reported and compared with the requirements. Energy deposition calculations with the MARS code have allowed to optimize parameters of inner absorbers and collimators in interconnect regions, thus reducing peak power density and dynamic loads to the tolerable levels.
Fermilab, Batavia, USA
BNL, Upton, Long Island, New York, USA
The requirements and operating conditions for superconducting magnets used in a Muon Collider Storage Ring are challenging. About one third of the beam energy is deposited along the magnets by the decay electrons. As a possible solution an elliptical tungsten absorber could intercept the decay electrons and absorb the heat limiting the heat load on superconducting coils to the acceptable level. In this paper we describe the main design issues of dipoles with an elliptical aperture taking into consideration the field and field quality. The temperature margin and the forces in the coils are presented as well.
Fermilab, Batavia, USA
CERN, Geneva, Switzerland
Fermilab, Batavia, USA
The planned upgrade of the LHC collimation system foresees additional collimators to be installed in the dispersion suppressor areas around points 2, 3, and 7. The necessary longitudinal space for the collimators could be provided by replacing some 8.33-T 15-m-long NbTi LHC main dipoles with shorter 11-T Nb3Sn dipoles compatible with the LHC lattice and main systems. To demonstrate this possibility, in 2011 Fermilab and CERN started a joint R&D program with the goal of building a 5.5-m-long twin-aperture dipole prototype suitable for installation in the LHC by 2014. The first step of this program is the development of a 2-m-long single-aperture demonstration dipole with the nominal field of 11 T at the LHC nominal current of ~11.85 kA and 60-mm bore with ~20% margin. This paper presents the results of magnetic analysis of the single-aperture Nb3Sn demonstrator dipole for the LHC collimation system upgrade.
LBNL, Berkeley, California, USA
Fermilab, Batavia, USA
SINAP, Shanghai, People's Republic of China
ICST, Harbin, People's Republic of China
Illinois Institute of Technology, Chicago, Illinois, USA
UMiss, University, Mississippi, USA
Recent progress on the design and fabrication of the RFCC (RF and Coupling Coil) module for the international MICE (Muon Ionization Cooling Experiment) will be reported. The MICE ionization cooling channel has two RFCC modules; each having four 201-MHz normal conducting RF cavities surrounded by one superconducting coupling coil (solenoid) magnet. The magnet is designed to be cooled by 3 cryocoolers. Fabrication of the RF cavities is complete; preparation for the cavity electro-polishing, low power RF measurements and tuning are in progress at LBNL. Fabrication of the cold mass of the first coupling coil magnet has been completed in China and the cold mass arrived at LBNL in late 2011. Preparations for testing the cold mass are currently under way at Fermilab. Plans for the RFCC module assembly and integration are being developed and will be described.