Exploring the Efficiency of RaF⁻ Production at ISOLDE

This thesis explores the efficiency of producing RaF⁻ anions from a beam of RaF⁺ cations through double charge exchange with sodium vapor. RaF is of particular interest in time-reversal and parity-violating physics, as it has been predicted to be sensitive to parity-violating moments such as the nuclear or electronic Electric Dipole Moment (EDM). Its sensitivity is due to the radium nucleus having a high atomic number, as well as the fact that some specific isotopes of Ra have a static octupole (pear-shaped) deformation. The production of RaF⁻ is proposed as a promising alternative to improve the trapping efficiency of RaF for high precision experiments. During the experiment at ISOLDE/CERN performed in December 2024, a beam of mass-selected RaF⁺ ions was delivered to the Collinear Resonance Ionization Spectroscopy (CRIS) setup and directed through a sodium vapor charge exchange cell, where sequential electron exchange reactions were expected to form neutral RaF and then, RaF⁻. In this thesis, several approaches were employed to estimate the cross section for this reaction and evaluate the efficiency of RaF⁻ production under varying charge exchange cell conditions in order to compare to experimental results. The overall objective of this thesis is to find out how the parameters within the charge exchange cell influence the probability of charge exchange to create RaF⁻ starting from the RaF⁺ beam.