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 $Nb_3Sn$ 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 Nb3Sn for an...
R2D2, the Research Racetrack Dipole Demonstrator, is a short model being developed within a collaboration between CEA Paris-Saclay and CERN aimed at developing key technologies for future high field 16 T $Nb_3Sn$ magnets for particle colliders. In the particular case of block-coil designs, two different cable grades are wound in the same coil layer, in order to maximize the current density,...
For future 20+ T accelerator type magnets, ReBCO tape based conductors are ideal for their capability of carrying high current densities in high magnetic field. At CERN, demonstrator dipole magnets using ReBCO conductor are being developed in order to study the feasibility of this technology. A key problem in such magnets is how to realize the coil ends when using ReBCO tape conductor without...
High energy physics research will need more and more powerful circular accelerators in the next decades, in order to explore unknown regions of particle physics. It is therefore desirable to have dipole magnets able to produce the largest possible magnetic field, in order to keep the machine diameter within reasonable size. A 20 T dipole is considered a desired achievement, since it would...
Recent years have seen significant development of high-temperature superconducting Bi-2212 wires and magnets in the US with record critical current density, record wire lengths and record performance model magnets. A dozen racetrack coils have been produced within the LBNL subscale accelerator magnet program using Bi-2212 Rutherford cables, including the record performance of RC6, which...
The cross-section design of cos $\theta$ superconducting magnets is historically developed in a two-step process: initially, the coil geometry is defined on the basis of magnetic optimizations; then, the structure is designed around the coil. The first step searches for the best coil cross-section maximizing the magnetic field, margin, field quality and conductor efficiency. The latter step...
