CRYRING is a heavy ion storage ring, formerly located at the Manne Siegbahn Laboratory at Stockholm University. During close to two decades of operation in Sweden, many significant scientific contributions to atomic and molecular physics were achieved using CRYRING. To further leverage its capabilities into the realm of intense beams of highly charged ions, of exotic  isotopes, and antiprotons, it has for long been proposed to relocate CRYRING from Sweden to GSI/FAIR. In cooperation with our Swedish partners and further international contributors, we are presently working on the CRYRING@ESR project.

In Darmstadt, the ring is being modernized and adapted to the GSI/FAIR standards and set up downstream of ESR (Report). There, it is to become both, a test bed for new FAIR technologies, as well as a new home for research with slow exotic ion beams for several collaborations of FAIR: SPARC, BioMat, FLAIR, and NuSTAR for pursuing precision measurements on forefront of atomic and nuclear physics and beyond. Details of our planned experiments are laid out in the Physics book.

CRYRING@ESR can store, cool and decelerate heavy, highly charged ions down to a few 100 keV/nucleon. It features excellent vacuum conditions to achieve ion beam lifetimes of several seconds to minutes for even the highest charge states of ions. It is equipped with a high performance electron cooler, as well as with a gas-jet target. Moreover, an independent injector beamline will allow for standalone operation during commissioning and prototyping while the FAIR accelerators are unavailable.

The ions are kept in orbit by twelve 30° magnetic dipoles and a number of magnetic quadrupoles and sextupoles (not shown in the figure) in six of the twelve straight sections. The other six sections house an injection and an extraction system, an rf-gap for deceleration and acceleration , and the electron cooler. Finally, one section is available for experimental installations as for instance a gas target.