DECAY STUDIES OF EXOTIC NUCLEI USING A REACTION PRODUCT MASS SEPARATOR AT MSU

A reaction products mass separator (RPMS) has been used to separate, by the ratio of mass to charge, the reaction products from the collisions of light, intermediate energy (appr. E/A = 30 MeV) nuclei with various targets. The decay modes of the separated nuclei were then studied in a low background environment. Measured in the first experiments with this device were the previously unknown lifetimes of 14Be(4.2(7)ms) and 17C (202(17)ms), and the β-branching ratios for the decay of 9C . The results are compared to shell-model calculations in order to understand the structure of the nuclei involved

Tracking rare-isotope beams with microchannel plates

International audienceA 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 56Ni 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 X 10{$^5} PPS