Particle identification using trajectory reconstruction with the ARIS separator system at FRIB

The production of radioactive beams is crucial to understand structure of atomic nuclei away from stability. The operation of FRIB will ultimately provide access to previously unreachable unstable nuclei. Radioactive beams produced at FRIB can be selected and purified using the Advanced Rare Isotope Separator (ARIS) for further study by users. Ions are identified based on the energy loss, magnetic rigidity, gamma rays, time of flight, total energy in a suite of detectors. The transport of cocktail beams to the end of ARIS can impact the path length and the measured flight time. This can lead to uncertainty in the particle identification and worse timing resolution can occur if not corrected for. Characterizing the ion optics with position-sensitive detectors allows for corrections to the flight path of the ions. This in conjunction with the use of transfer matrices allows for the particle’s trajectory to be reconstructed and thus correct for the variation in the measured time of flight. These corrections are crucial for enhancing charge-state identification, especially in a high-resolution optics mode. The impact of applying a trajectory reconstruction method will be presented.