20 T Hybrid Nb3Sn-HTS Block-Coil Designs for a Future Particle Collider
Résumé
Future high energy particle colliders are under study, with a first goal of 16 T dipoles, which is believed to be the practical limit of Nb
3
Sn magnets. Another more ambitious goal is to aim for 20 T dipoles. This very high field would require High Temperature Superconductors (HTS), such as Bi2212 or REBCO. Their substantially higher cost necessitate anyways the use of Nb
3
Sn for an affordable accelerator application. Therefore, hybrid designs can be proposed, where the HTS are used in the high field (16–20 T) area, and Nb
3
Sn are used in the low field (<16T) area. Rectangular block-coil designs are particularly well adapted to this concept, since the separation between high field and low field can be made parallel to the cable turns, inside each layer of the coil. However, the large forces accumulating on the cable turns generate a high transverse stress detrimental to the coil. The paper presents a conceptual Hybrid Nb
3
Sn-HTS design generating 20 T in the bore with margin, using a block-coil concept. Several conductor options are discussed. The design also proposes stress-management solutions to deal with the large stress developing in the coils.
Mots clés
Conductors
High-temperature superconductors
Stress
Magnetomechanical effects
Superconducting magnets
Current density
Iron
accelerator magnets
high-temperature superconductors
niobium alloys
particle accelerators
superconducting cables
superconducting coils
superconducting magnets
tin alloys
rectangular block-coil designs
high transverse stress
high energy particle colliders
high temperature superconductors
accelerator application
HTS block-coil designs
stress-management solution
REBCO
Nb3Sn
High field magnet
HTS
hybrid magnet
magnetic design
accelerator, superconductivity
coil, superconductivity
energy, high
particle, energy
magnet, superconductivity
niobium, alloy
temperature, high
current, density
accelerator, magnet
iron, density
superconductivity, temperature, high
hybrid
dipole
transverse
tin
costs