Superconducting Magnets for Accelerators

Abstract

Superconducting magnets have enabled great progress and multiple fundamental discoveries in the field of high-energy physics. This chapter reviews the use of superconducting magnets in particle accelerators, introduces Nb 3 Sn superconducting accelerator magnets, and describes their main challenges. 1.1 Circular Accelerators and Superconducting Magnets Circular accelerators are the most important tool of modern high-energy physics (HEP) for investigating the largest mass and the smallest space scales. A key element of a circular accelerator is its magnet system (Wolski 2014). The magnet system is composed of large number of various magnets, mainly dipoles and quadrupoles, to guide and steer the particle beams. The main function of the majority of the magnets (the so-called arc magnets, which are periodically placed along a ring) is to keep the beam on a quasi-circular orbit and confine them in a relatively small and welldefined volume inside a vacuum pipe. Magnets are also used to transfer beams between accelerator rings in so-called transfer lines, to match beam parameters from the transfer line into the injection insertions or into extraction lines and beam dumps, to direct or separate beams for the accelerating radio frequency cavities, and to focus beams for collision at the interaction points where the experiments reside. One of the most important parameters of colliders is the beam energy, as it determines the physics discovery potential. The energy E in GeV of relativistic particles with a charge q in units of the electron charge in a circular accelerator is limited by the strength of the bending dipole magnets B in Tesla and the machine radius r in meters

Collimation of partially stripped ions in the CERN Large Hadron Collider

“…The primary purpose of those collimators is to intercept dispersive losses coming from the betatron-collimation insertion and studies show that their presence can reduce the losses in the DS for both proton and ion beams [18,40,42]. To make space for the TCLD, a standard 8.33 T, 15 m-long main dipole will be replaced by two shorter, 5 m-long 11 T dipoles, based on the Nb 3 Sn superconducting alloy, with the collimator assembly in the middle [43]. The planned location for the TCLD installation at the longitudinal position s=20310 m, see Fig.…”