"A better technical approach is to stop the beams, extract them and then reaccelerate them or use them at low energies," writes Don Monroe in a feature for the July/August CERN Courier, describing the various ways to create low-energy beams for rare isotope research. "This is the path that MSU has opted for in upgrading its NSCL facility."
"To provide isotope beams with lower and more tightly distributed energies, it will combine new and established technology to stop the beams, increase the charge on the ions and then reaccelerate them. The resulting beams will enable users at NSCL to explore the excitations of rare isotopes – by either nucleon transfer or Coulomb excitation – to reveal their internal structure."
More information on stopped and reaccelerated beams at the laboratory is available on the Experimenters section of the NSCL Web site.