HTS Superferric Combined Function Magnet for the FCC-ee Project

Energy consumption represents an increasing critical challenge for particle physics research laboratories like CERN. This issue is particularly significant in large accelerator facilities, where normal conducting magnet technology plays a fundamental role in the beamline design. In this context, research, development, and study of high-temperature super conducting (HTS) magnets offer promising solutions to improve energy efficiency. HTS materials can substantially reduce energy consumption and operational costs enabling higher operating temperatures compared to conventional superconductors. When combined to superferric magnets designed, this technology can offer simpler, cost-effective designs, exploiting the iron yoke pole shape for magnetic field quality reducing the influence of the high temperature superconductor large magnetization effect. In this paper, a combined superferric (sextupole and quadrupole) HTS magnet for the FCC-ee main ring is described. The main goal of this proposal is to produce the same performances of the current resistive magnet configuration while reducing magnet length in the accelerator. This design increases the dipole filling factor, which offers a slight decrease in overall energy consumption through reduced RF cavity power requirements or improved beam luminosity at constant RF power consumption. Furthermore, a preliminary thermo-mechanical study is reported to have an initial look at the power consumption of the magnets. This project targets high-energy, low-field particle accelerators, leveraging the use of iron yokes to minimize the required HTS material, hence the cost of the magnet, and reduce even more the manufacturing technologies needed. This approach balances cost efficiency with performance, offering significant progress in sustainable accelerator technology.