Ion-optical design of High energy FRagment Separator (HFRS) at HIAF

High Intensity heavy-ion Accelerator Facility (HIAF) project is being constructed by the Institute of Modern Physics, Chinese Academy of Sciences (IMP, CAS). An in-flight High energy FRagment Separator (HFRS) at HIAF was designed to study the properties of rare isotopes far away from the line of beta stability and their involved nuclear reactions of astrophysics interests. HFRS is a two-stage magnetic system which consists of Pre-Separator and Main-Separator. The maximum magnetic rigidity of 25 Tm was designed in particular for experiments with very neutron-rich rare isotopes beams and studies of hypernuclei and Δ-resonances in exotic nuclei. A dispersive mode and an achromatic mode were designed for different experimental requirements. The HFRS device can be used to separate and purify the rare isotopes produced by the projectile fragmentation of all primary beams up to Uranium or by the projectile fission of Uranium ions via Bρ-ΔE-Bρ method. The detailed HFRS ion-optical design including the first order and the higher order, and the magnet specification were presented in this paper.