Experimental Study of the Electromagnetic Transitions in Neutron-rich 22F

The excited states in the neutron-rich nucleus 22F were investigated using the 9Be(18O, α p)22F fusion-evaporation reaction. A 3 MeV/u 18O beam was delivered by the Argonne Tandem Linac Accelerator System (ATLAS). Prompt γ rays were detected using the 2π Gamma-Ray Energy Tracking In-beam Nuclear Array (GRETINA), comprising 48 high-purity germanium crystals. The recoiling 22F residues were identified and selected via the α + p channel using the Fragment Mass Analyzer (FMA). Doppler-corrected γ-γ coincidence spectra revealed new levels and transition branches. Spin and parity assignments were extracted from angular distribution and linear polariza-tion measurements. A transition level scheme was constructed, showing evidence for intruder configurations and single-particle excitations. The experimental results were compared with shell-model calculations using the FSU interaction, providing insight

into configuration mixing and shell evolution near the neutron dripline.