Precision measurements with laser spectroscopy for nuclear structure studies at the BECOLA/RISE facility at FRIB*

Laser spectroscopy techniques have been extensively used for nuclear structure studies [1]. Among others, the collinear laser spectroscopy technique is almost exclusively applied to short-lived rare isotopes thanks to its high sensitivity. Nuclear spins, electromagnetic moments and differential mean-square charge radii can be deduced model independently from the hyperfine spectra and their isotope shifts. At the BEam COoling and LAser spectroscopy (BECOLA) facility [2, 3] at FRIB, the laser resonant fluorescence measurement, and the laser Resonant Ionization Spectroscopy Experiment (RISE), which has recently been developed in collaboration with MIT, are performed on low-energy (typically 30 keV) beams delivered from FRIB’s stopped beam systems [4, 5, 6]. Current status of the facility, recent science highlights and future plans will be discussed. 

[1] X.F. Yang, S.J. Wang, S.G. Wilkins, R.F. Garcia Ruiz, Prog. Prat. Nucl. Phys. 129, 104005 (2023).

[2] K. Minamisono et al., Nucl. Instrum Methods Phys. Res. A 709, 8 (2013).

[3] D. M. Rossi et al., Rev. Sci. Instrum. 85, 093503 (2014).

[4] C.S.Sumithrarachchi et al., Nucl. Instrum. Methods Phys. Res. B 463, 305 (2020).

[5] K. Lund et al., Nucl. Instrum Methods Phys. Res. B. 463 378-381 (2020).

[6] C.S. Sumithrarachchi et al., Nucl. Instrum. Methods Phys. Res. B 541, 301 (2023).