Optimizing and Stabilizing MR-TOF Electrode Voltages for ATLAS N=126 Factory and nuCARIBU

At the two newest radioactive isotope beam facilities at Argonne National Laboratory's ATLAS Accelerator, the N=126 Factory and nuCARIBU, Multi-Reflection Time of Flight Mass Spectrometers (MR-TOF-MS) serve important roles in both beam purification and mass measurements. An MR-TOF-MS uses electrostatic mirrors to repeatedly reflect ion bunches of similar energy but differing masses, allowing separation of ions by mass due to differing velocities over a long trajectory. These mirror electrode voltages being both optimally set and stable is essential during extended experimental measurement times. To improve the efficiency and reliability of these instruments, simulations of the ion injection optics have been run and analyzed. Currently, the cooler-buncher that precedes the MR-TOF produces a large ion position-momentum distribution, diminishing ion acceptance into the MR-TOF-MS. By scanning the electrode voltage parameter space, acceptance of bunched ions has been improved. Additionally, work has been done on improving the electrode voltage active stabilization loop and passive RLC filters, to improve voltage precision and reduce drift and jitter. Overall, this work will help to improve beam quality and allow more precise exotic isotope mass measurements from these facilities.