Investigation of various material properties for a Cherenkov detector at the Facility for Rare Isotope Beams

The Facility for Rare Isotope Beams located on the campus of Michigan State University in the United States started its scientific program in May 2022, becoming the most powerful facility to study exotic nuclei with energies up to 200 MeV/u. Over the past two decades, the MoNA Collaboration has established a strong program for the understanding of the reaction mechanism and spectroscopy of extreme neutron rich nuclei along the dripline using the invariant mass technique. These nuclei decay by emitting a charged fragment and one or multiple neutrons. At FRIB energies, properly identifying the charged fragments will become a challenge due to their high velocities. A Cherenkov detector is under study to complement the existing charged detector system and improve its particle identification. The optical properties (transmittance, specular reflectance, diffuse reflectance) of several materials (4H SiC, GaN, multilayer graphene (MLG), single layer graphene (SLG), silicon diamond like carbon (Si-DLC), and Si) were investigated before and after hydrogen implantation. Ion-implantation induced defects in the different semiconductors studied, and their formation and evolution with fluence and thermal annealing will be presented and compared. This work was done in collaboration with the CEMHTI (UPR 3079 CNRS) and Université d'Orléans in France.