GSI, Darmstadt
The FAIR Storage Rings (CR, RESR and NESR) are designed for efficient cooling, accumulation, deceleration and performing nuclear physics experiments with antiproton and rare isotopes beams. Tracking studies for all these rings have been performed to estimate the dynamic aperture and other properties of beam stability depending on the low and high field multipole components, fringe fields and field interference. The multipole limits have to be determined in order to provide a reasonable estimate of the stability boundary and needed correction of the low field multipoles. We report on quantitative studies of the effects of multipoles on the dynamic aperture of the rings, and show that the systematic multipole components in the present magnet designs are unlikely to impose a severe limitation.
GSI, Darmstadt
CERN, Geneva
The FAIR storage ring complex comprises three storage rings with a magnetic rigidity of 13 m. Each of the rings, CR, RESR, and NESR, serves specific tasks in the preparation of secondary beams, rare isotopes and antiprotons, or for experiments with heavy ion beams. The CR is optimized for fast stochastic pre-cooling of secondary beams. The RESR design includes optimization of antiproton accumulation. The design of the NESR for experiments with heavy ions, deceleration of ions or antiprotons for a subsequent low energy facility, and the accumulation of rare isotope beams is proceeding. This report summarizes various new concepts conceived in the design process of this new storage ring facility.
GSI, Darmstadt
The main purpose of the Recuperated Experimental Storage Ring (RESR) in the FAIR project is the accumulation of antiprotons coming from the Collector Ring (CR), where they are stochastically pre-cooled. The accumulation scheme in the RESR foresees longitudinal stacking in combination with stochastic cooling. The stochastic cooling process strongly depends on the slip factor η of the ring. Presently, the RESR is designed to operate with small slip factor of 0.03. In order to increase the flexibility for optimized stochastic cooling a new alternative ion-optical mode with higher slip factor of 0.11 has been calculated in such a way, that the RESR can be operated with a fixed magnetic structure in both modes. The influence of the high-order chromaticity on the particle motion has been investigated and a chromaticity correction scheme is applied. The variation of the transition energy over the momentum acceptance was examined and the possibility of its correction is described.