Superconductivity is the technology that enabled the construction of the most recent generation of high-energy particle accelerators, the largest scientific instruments ever built. In this review we trace the evolution of superconducting materials for particle accelerator magnets, from the first steps in the late 1960s, through the rise and glory of Nb–Ti in the 1970s, till the 2010s, and the promises of Nb3Sn for the 2020s. We conclude with a perspective on the opportunities for high-temperature superconductors (HTSs). Many such reviews have been written in the past, as witnessed by the long list of references provided. In this review we put particular emphasis on the practical aspects of wire and tape manufacturing, cabling, engineering performance, and potential for use in accelerator magnets, while leaving in the background matters such as the physics of superconductivity and fundamental material issues.

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Superconducting Materials and Conductors:. Fabrication and Limiting Parameters

A review on independent and integrated/coupled two-phase loop thermosyphons

CMS (compact muon solenoid) is a general-purpose detector designed to run at the highest luminosity at the CERN Large Hadron Collider (LHC). Its distinctive features include a 4 T superconducting solenoid with 6 m diameter by 12.5 m long free bore, enclosed inside a 10,000-ton return yoke. The stored magnetic energy is 2.6 GJ. The magnet is being assembled in a surface hall and will be tested at the beginning of 2005 before being transferred to an experimental hall 90 m below ground level. The design and construction of the magnet is a common project of the CMS Collaboration. The task is organized by a CERN based group with strong technical and contractual participation of CEA Saclay, ETH Zurich, Fermilab, INFN Genova, ITEP Moscow, University of Wisconsin and CERN. The return yoke, 21 m long and 14 m in diameter, is equivalent to a thickness of 1.5 m of saturated iron interleaved with four muon stations. Manufacture of the yoke and vacuum tank is completed and the first sub-detectors have been installed. The indirectly-cooled, pure-aluminum-stabilized coil is made up from five modules internally wound with four layers of a 20 kA mechanically-reinforced conductor. The manufacture of the conductor is completed and winding is in progress for a final assembly in 2004. All ancillaries are delivered or under contract. The magnet project is described, with emphasis on the present status of the fabrication.

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Status of the construction of the CMS magnet

The CMS experiment (Compact Muon Solenoid) is a general-purpose detector designed to run at the highest luminosity at the CERN Large Hadron Collider (LHC). Its distinctive features include a 4 T superconducting solenoid with a free bore of 6 m diameter and 12.5-m length, enclosed inside a 10 000-ton return yoke. The magnet will be assembled and tested in a surface hall at Point 5 of the LHC at the beginning of 2004 before being transferred by heavy lifting means to an experimental hall 90 m below ground level. The design and construction of the magnet is a common project of the CMS Collaboration. The task is organized by a CERN based group with strong technical and contractual participation from CEA Saclay, ETH Zurich, Fermilab, INFN Genova, ITEP Moscow, University of Wisconsin and CERN. The magnet project will be described, with emphasis on the present status of the fabrication.

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Status of the CMS magnet (MT17)

Within the framework of the LHC (Large Hadron Collider) R&D program, CERN and CEA/Saclay have established a collaboration to carry out the design, building and testing of a superconducting LHC prototype quadrupole at the Saclay laboratory. The cold mass of this quadrupole is presently under construction at Saclay. The quadrupole design features a twin aperture configuration, a gradient of 250 T/m, a length of 3 m, and a free coil aperture of 56 mm. European industries participate in this project by delivering components and fabricating the tooling according to specifications prepared by Saclay. The authors present details of the magnet design and construction. Coil winding will start in summer 1991 and the first prototype should be assembled and ready for testing by mid 1992. >

Design and fabrication of the prototype superconducting quadrupole for the CERN LHC project

A large superconducting solenoid (5-m bore, 7-m length) has been designed and constructed at the CEN/Saclay for the ALEPH detector, to be installed on the LEP collider at CERN. Special features of this solenoid are described such as the Al-stabilized superconducting cable, bobbinless internal winding, vacuum impregnation, indirect cooling, thermosyphon refrigeration mode, cryostat assembly. Preliminary tests without the iron carried out successfully in April 1987, and a complete test with the iron calorimeter at CERN in September 1987 are briefly reviewed. >

Design, construction and test of the large superconducting solenoid ALEPH

Within the framework of a collaboration with IHEP for the UNK project, two test stands have been built and delivered to measure the magnetic characteristics of the UNK superconducting quadrupoles: location and transfer of the magnetic axis, gradient value, and homogeneity. The authors describe the different parts of the apparatus, in particular the carbon-fiber measuring tube which enables the sag of the measuring devices to be minimized. Emphasis is placed on the mechanical measurements and controls made on the measuring tube, the wire system used to locate the magnetic axis, and the optical elements selected for the alignment. Preliminary results obtained in the USSR are reported. >

J. Lebars

Papers

Design, construction and test of the large superconducting solenoid ALEPH

Magnetic measurement stands for the UNK superconducting quadrupoles