Design of a monitoring and charge radii measurement system for rare isotope beams using the Rutherford scattering process*

Rutherford's alpha particle scattering experiment was one of the milestones for the physics community as it provided insights into an atom thus disregarding the Thomson's model. This model evolved over the years to provide more accurate representations of the scattering process. At high energies, the incoming ion probes both the charge (e.g., Coulomb) and nuclear (e.g., interference pattern) responses of the nuclear matter. Therefore, the elastic scattering of ions can provide key information about nuclear charge radii. This presentation will report on an effort by the MoNA Collaboration to design a detector that will provide simultaneously: 1) a normalization between experiments conducted with rare isotope beams at FRIB and 2) a possible experimental measurement of charge radii of rare isotopes. A low energy calibration of our Geant4 Monte Carlo simulation was performed by comparing simulated data to measurements using a Leyboldã kit of the original Rutherford experiment on gold and aluminum foils. A beam of 5.4 MeV alphas from an 241Am source impinged on each target. The signals from a silicon diode detector were acquired using the 8-channel DT57255S digitizer from CAEN and the offline analysis using python. The simulation is now being expanded to evaluate the performances of the detector using a silicon or GEM based design. This presentation will provide a status on the data analysis to benchmark our simulation as well as expected performance for this device.