Tracking rare-isotope beams with microchannel plates

Abstract A system of two microchannel-plate detectors has been successfully implemented for tracking projectile-fragmentation beams. The detectors provide interaction positions, angles, and arrival times of ions at the reaction target. The current design is an adaptation of an assembly used for low-energy beams ( ~ 1.4 MeV / nucleon ) . In order to improve resolution in tracking high-energy heavy-ion beams, the magnetic field strength between the secondary-electron accelerating foil and the microchannel plate had to be increased substantially. Results from an experiment using a 37-MeV/nucleon 56 Ni beam show that the tracking system can achieve sub-nanosecond timing resolution and a position resolution of ~1 mm for beam intensities up to 5 × 10 5 pps .