FRIB, East Lansing, Michigan, USA
Radiation transport simulations reveal shortcomings in the use of ion chambers for the detection of beam losses in low-energy, heavy-ion accelerators like FRIB. Radiation cross-talk effects due to the specific FRIB paper-clip geometry complicate locating specific points of beam loss. We describe an economical and robust solution that complements ionization chambers. A specifically designed device, the halo monitor ring (HMR), is implemented upstream of each cryomodule to detect beam loss directly. Together with fast response neutron scintillators, the new integrated BLM system satisfies both machine protection and sensitivity requirements.
