Superconducting Magnets in Accelerators

Abstract

AbstractParticle accelerators and high-field superconducting magnets had been the greatest promoters of each other. In accelerators, RF power is used to boost the beam energy through the use of superconducting (RF) cavities. Bending, focusing and steering of the beam is provided by superconducting magnets. Fundamentally, an accelerator can either be of circular type or linear. Circular accelerators like Large Hadron Collider (LHC) are suitable for heavy ions like protons because the energy loss caused by synchrotron radiation in a circular accelerator varies inversely to the fourth power of the mass of the ion. Brief discussion on the superconducting colliders built and operated, namely Tevatron, HERA, SSC, RHIC prior to LHC have been given in the chapter. LHC magnets have been discussed in greater details. LHC, world’s most powerful particle accelerator has, been in operation since 2009 and has yielded vast data and has confirmed the existence of Higgs boson. Parameters of the collider magnet system and the specifications of the conductor used are presented. Innovative magnet designs and development of superior conductors have been included. Linear accelerator is the choice for light particle like electrons and positrons. An international effort has been made to build a 31 km long linear collider named International Linear Collider (ILC) for colliding electrons and positrons with a collision energy of 500 GeV (~1 TeV in future). World’s first superconducting cyclotron of the class K-500, world’s biggest cyclotron, K-1200 (both at MSU) and the world’s biggest ring cyclotron, RIKEN SRC K-2500 have been described. K-1200 can accelerate U to 90 meV and the SRC K-2500 up to 350 meV. The successor of LHC, namely the high-luminosity LHC (HL-LHC), and the Future Circular Collider (FCC) are also discussed towards the end. Nb3Sn quadrupole and dipole magnets developed for the two projects have been described. The chapter closes with the expectation that LTS capability of producing high magnetic field would be exhausted soon, and reliance will be made on HTS cables which are already being developed for DEMO TF coils.