Development of position-sensitive detectors for enhancing mass measurement in the Rare-RI Ring

Mass measurement studies of r-process isotopes are crucial for solving the long-standing question on the origin of the elements, particularly beyond the iron peak.Two position-sensitive detectors have been developed to improve the precision of the Rare Radioisotope Ring (R3), a mass measurement facility at RIKEN, Japan.The first is a thin-foil based detector, the Delay Line Electric-field MCP detector, made to replace the current gas-filled detectors that introduce energy straggling which worsens precision.Additionally, it can provide turn by turn position diagnostics for improving the efficiency of the ring.The DLEMCP has been tested with a 200~MeV/u $^{84}$Kr beam and reached a position resolution of 1.3~mm, an improvement of over 20\%.The next step is to test it with a heavy ion beam at R3 to check its performance in experimental conditions - in the vicinity of large magnets and noisy electronics.The second is a position-sensitive resonant Schottky Cavity Doublet (SCD) which uses the induced energy stored inside to determine the position.It aims to take measurements inside the storage, ring rather than upstream, to improve the correction for the beam's momentum spread which must be performed to reach the desired relative mass resolution of $10^{-6}$.By removing the need for the upstream position detectors, energy straggling can also be reduced, and more neutron rich high Z beams, such as $^{216-220}$Pb and $^{219-220}$Bi, can be delivered without charge interactions altering its purity.The SCD has undergone limited testing as it requires a beam continually circulating inside a storage ring to be fully functional.What tests have been performed show that it is operational.It has been fully installed and awaits experimental time inside R3. The data processing method is detailed to show how the raw position and frequency data is corrected and converted into a mass value.