Towards Rydberg State Ionization of Aluminum

The possible abnormal proton-halo structure in ²²Al will be studied in the BECOLA facility through laser spectroscopy. As a preparatory study, this contribution has summarized the efforts towards the development of a two steps resonance ionization scheme using Rydberg states for stable ²⁷Al. The development of the scheme has been pursued in two different directions. On one side, the Sirah Cobra dye laser has been prepared to study the Rydberg states on the 420-460 nm wavelength range. On the other side, the hyperfine spectrum of the 3s²3p²P_3/2 → 3s²4s²S_1/2 transition has been measured using CLS fluorescence spectroscopy, extracting the hyperfine coupling constants.