Novel Fragment Separators at CERN-ISOLDE: the ISRS and ISLS projects

The HIE-ISOLDE facility at CERN can provide more than 1000 isotopes of about 70 elements at energies around 0.5 – 10 MeV/u. The ISOLDE Superconducting Recoil Separator (ISRS), based on a superconducting particle-storage ring of few meters’ diameter, has been proposed to expand the HIE-ISOLDE physics program. Innovative concepts and cutting-edge technologies will allow ISRS to achieve unprecedented mass-resolving power. Its design features nested-multifunction Canted Cosine Theta (CCT) superconducting magnets, and an innovative Fixed-Field Alternating Gradient beam dynamics. During the CERN Long Shutdown 3 (LS3, 2026-2028) the R&D program will focus on the installation and testing of prototypes, such as the new ISOLDE multi-harmonic buncher and the prototype of CCT superconducting magnet MAGDEM, the building block of the ISRS ring. MAGDEM can be integrated into an innovative spectrometer, the so-called ISOLDE Linear Spectrometer (ISLS), which can be operative after LS3 and used to resolve light reaction recoils. In this paper we review nuclear physics opportunities as well as ISRS and ISLS design features and technologies.