Optics and beam dynamics study of the ISOLDE superconducting recoil separator

Abstract

The spectrometry of radionuclides is a key area in nuclear physics, driven by the global quest to discover and characterize exotic isotopes. We propose a versatile and compact storage ring, the ISOLDE Superconducting Recoil Separator (ISRS), envisioned as an innovative high-performance spectrometer for HIE-ISOLDE at CERN. The design incorporates ten iron-free superconducting combined-function Canted Cosine-Theta magnets, taking as a reference the so-called MAGDEM prototype, which is also being developed as part of the ISRS project. Using the actual dimensions of MAGDEM, this study explores the beam dynamics possibilities for the ISRS ring, with a particular focus on its performance as a separator for high rigidity beams, up to 2 T m. Taking 234Ra+53 at 10 MeV/u as the reference ion, the ring operates under isochronous conditions, enabling separation of isotopes based on their mass-to-charge ratios relative to the reference ion. Time-of-Flight (ToF) detection is proposed after only ten turns. Alternative beam dynamics configurations are considered, particularly around the isochronicity condition, which offer greater stability conditions of the circulating beam. These approaches focus on studying key lattice and beam optics parameters, such as momentum acceptance, and ring tune, while also illustrating a practical case of isotope separation.