Superconducting Magnets for Particle Accelerators

Abstract

Superconductivity has been the most influential technology in the field of accelerators in the last 30 years. Since the commissioning of the Tevatron, which demonstrated the use and operability of superconductivity on a large scale, superconducting magnets and rf cavities have been at the heart of all new large accelerators. Superconducting magnets have been the invariable choice for large colliders, as well as cyclotrons and large synchrotrons. In spite of the long history of success, superconductivity remains a difficult technology, requires adequate R&D and suitable preparation, and has a relatively high cost. Hence, it is not surprising that the development has also been marked by a few setbacks.This article is a review of the main superconducting accelerator magnet projects; it highlights the main characteristics and main achievements, and gives a perspective on the development of superconducting magnets for the future generation of very high energy colliders.To be published in Reviews of Accelerator Science and Technology, Vol. 5Geneva, Switzerland CERN-ATS-2013-019February 2013 Superconductivity has been the most influential technology in the field of accelerators in the last 30 years. Since the commissioning of the Tevatron, which demonstrated the use and operability of superconductivity on a large scale, superconducting magnets and rf cavities have been at the heart of all new large accelerators. Superconducting magnets have been the invariable choice for large colliders, as well as cyclotrons and large synchrotrons. In spite of the long history of success, superconductivity remains a difficult technology, requires adequate R&D and suitable preparation, and has a relatively high cost. Hence, it is not surprising that the development has also been marked by a few setbacks. This article is a review of the main superconducting accelerator magnet projects; it highlights the main characteristics and main achievements, and gives a perspective on the development of superconducting magnets for the future generation of very high energy colliders.

A viable dipole magnet concept with REBCO CORC®wires and further development needs for high-field magnet applications

“…For a no-iron, perfect cos θ current distribution, the dipole field is proportional to the coil width [42,43]. The 1.5 ratio between the dipole transfer functions of two designs (figure 14) agrees with this analytic result because here the coil width is proportional to the number of layers.…”

Superconducting Materials and Conductors: Fabrication and Limiting Parameters

“…An efficient winding requires a coil current density J avg , averaged over all coil components, in the range of 400-500 A/mm 2 . Significantly smaller values result in coils that are too large and too costly [23,42]. Much larger values in magnets producing the strong fields of interest here would yield mechanical stresses in the winding exceeding allowable levels for the superconductor, or other coil components such as the insulation, and may be difficult to protect in case of quench.…”

“…The latest achievement is the Large Hadron Collider (LHC) [22], which will soon be pushing the operating field to the 8 T range, the practical boundary of Nb-Ti for this class of applications. The companion paper [23] contains an abridged history of the research and achievements in the field of superconducting accelerator magnets.…”

Superconducting Materials and Conductors: Fabrication and Limiting Parameters

“…In practice, this is not always possible due to conflicting demands on construction materials. As to transverse loading, the stress generated by the Lorentz load depends on the current density and the thickness of the winding pack [23]. A thin winding pack with high J avg makes very effective use of the superconductor, but experiences higher stress than a thicker winding pack with a lower J avg .…”