MOA2PL02
FRIB, East Lansing, USA
The Facility for Rare Isotope Beams (FRIB) is under construction at the Michigan State University. The driver linac consists of a front-end, three superconducting segments connected by two 180-degree bending sections, and a beam delivery system, which will accelerate all stable ions beyond 200 MeV/u and deliver beam to a fragment target with power up to 400 kW. The front-end beam commissioning has been completed recently, and the commissioning of the first three cryomodules is underway. This talk will update the accelerator physics associated with construction and commissioning, present initial beam commissioning results, and report the current status of the project.
WEA2WB01
FRIB, East Lansing, USA
Machine errors and interaction of ion beam with the stripper are known sources of possible beam losses in ion linacs. Our studies show that contaminant ion beams extracted from Electron Cyclotron Resonance ion source and accelerated together with main beam thanks to similar charge-to-mass ratio can produce substantial losses after the stripping due to modified charge-to-mass ratio. The contaminant beams must be well separated and collimated at low energies to avoid losses in the high energy section of the linac. An additional mechanism for beam losses is charge-exchange reactions in the residual gas near the charge selection slits. A set of collimators have been developed to intercept both contaminant ions and main beam halo in the example of Facility for Rare Isotope Beams (FRIB).