Image courtesy of MSL.


  • F. Herfurth, et al., "Precision measurements with highly charged ions at rest: The HITRAP project at GSI", International Journal of Mass Spectrometry, 251 (2006), p. 266.
  • H. Danared et al., LSR - Low-energy Storage Ring, Technical design report, Tech. Report version 1.3, Manne-Siegbahn Laboratory, Stockholm University, 2011.
  • F. Herfurth, et al., "The Low Energy Storage Ring CRYRING@ESR", Proc. Cool13, Murren, Switzerland (2013).
  • C.P. Welsch, et al., "An ultra-low-energy storage ring at FLAIR." Nucl. Instr. Meth. A 546.3 (2005): 405-417.

Image courtesy of Cockcroft Institute.

The LSR shall decelerate and cool antiprotons down to 300 keV. The former CRYRING facility was identified as an ideal match for this purpose and the ring was successfully transferred to GSI and installed behind the existing ESR facility. The LSR ring shall be commissioned from December 2015 and prepared for operation within FAIR.


For post-deceleration of antiprotons from 4 MeV to energies in the range of keV a linear Interdigital H-mode (IH) drift-tube structure operated at 108 MHz followed by an RFQ decelerator will be used. After extensive tests and a thorough redesign the RFQ was finally taken into operation at GSI during an on-line test beam time in 2014.

The FLAIR facility consists of two storage rings, a magnetic (LSR) and an electrostatic (USR) one, and a universal trap facility (HITRAP). These shall provide stored as well as fast and slowly extracted cooled beams of antiprotons at energies between 30 MeV and 300 keV (LSR), between 300 keV and 20 keV (USR), and at rest or at ultra-low eV energies (HITRAP). This shall allow a large variety of novel experiments to be performed.

Cooled beams of antiprotons at even lower energies shall be provided by the USR. This electrostatic storage ring is a real multi-purpose facility in itself, providing shortest beam pulses in the nanosecond regime for in-ring collision experiments, and slowly extracted beams for nuclear physics-type experiments. The USR is a novel storage ring concept that shall provide unique experimental opportunities.

Image courtesy of GSI