Status of the Storage Ring Design at FAIR

Abstract

The large acceptance Collector Ring (CR) together with the High Energy Storage Ring (HESR) is the storage ring which will be realized in the Modularized Start Version (MSV) of the FAIR project. It will be operated in three ion-optical modes, two of them providing fast pre-cooling of either antiprotons or RIBs. The CR design was recently adapted to the use as a pre-cooling ring for subsequent beam accumulation in the HESR. The third mode, namely the isochronous mode, is a special ion-optical setting for mass measurement of exotic very short-lived nuclei. In this mode the CR will be operated as a Time-Of-Flight (TOF) spectrometer. The latest results of the general storage ring concept at FAIR will be presented and future perspectives of the ring complex development will be discussed.

The ILIMA project at FAIR

“…Isochronous Mass Spectrometry (IMS) is based on the isochronous ion-optical mode of the ring, in which ∆v/v of the ions -injected with energies corresponding to γ ≈ γ t -is nearly exactly compensated by the lengths of their orbits in the ring [33,34]. In the ESR γ t (ES R) ∼ 1.4 [31,32] whereas in the CR γ t (CR) = 1.4 − 1.8.…”

“…It is therefore the prime focus of attention for the ILIMA collaboration. The CR is a multipurpose device which will provide fast stochastic pre-cooling of antiprotons and heavy-ion beams, and is also a dedicated facility for isochronous mass measurements [33]. Particular care has been given to the ion-optical matching of the Super-FRS and CR to achieve close to unity transmission of the secondary beams [34].…”

Isochronicity correction in the CR storage ring

“…[8]. The isochronous mode has been calculated for different values of γ t [9]. In this paper we will always refer to the mode for γ t = 1.67 which allows to measure masses up to m/q = 3.1 u/e.…”