Identification of new actinide isotopes with FIONA

At the 88-inch cyclotron facility of Lawrence Berkeley National Laboratory the nuclear properties of exotic heavy elements are studied using the FIONA (for the identification of nuclide A) apparatus coupled to the Berkeley Gas-filled Separator (BGS). Actinide and transactinide isotopes created in fusion-evaporation reactions are collected using the BGS and either delivered to a detector station where their decay properties can be examined or they are injected into FIONA for A/q identification. The FIONA system is responsible for stopping, bunching, and accelerating ions coming from the BGS and efficiently transporting them to a low-background experimental area where their mass numbers are unambiguously identified using a trochoidal spectrometer, capable of a mass resolving power up to m/△m = 300. By direct observation of the mass number we are able to differentiate between neighboring isotopes and accurately assign them to their respective alpha decay properties observed at the BGS focal plane. Here, we will describe the FIONA apparatus and highlight recent experimental campaigns, including a search for new proton-rich isotopes of einsteinium (Z = 99).