Hyperfine structure and isotope shift measurements of the 4f76s2(S7/2o8)-4f76s6p(P9/28) 601.8154 nm transition in Eu I by laser induced atomic beam fluorescence spectroscopy

•Precision measurement of isotope shift and hyperfine structure constants of europium for the 4f76s2(S7/208)-4f76s6p(P9/28) transition.•Hyperfine separations of the ground and excited states have been measured by the laser induced fluorescence technique.•The hyperfine separations of the ground state have measured using the EOM technique.•The hyperfine separations of the excited state have measured using the AOM locking technique.•The hyperfine anomaly has been estimated to be 0.56 (3)%.

The hyperfine structure of the ground state 4f76s2(S7/2o8) and the excited 4f76s6p(P9/28) state for both the isotopes 151Eu and 153Eu has been measured using the laser induced fluorescence spectroscopy from an effusive atomic beam. The isotope shift for the 4f76s2(S7/2o8)→601.8154nm4f76s6p(P9/28) transition of Eu I has also been measured. The precision in the measurement of the isotope shift of this transition and the hyperfine structure constants for both the isotopes of Eu has been improved using a radio-frequency modulation technique based on EOM side band generation as well as by frequency locking technique. The experimentally determined isotope shift between the 151Eu and the 153Eu isotopes for the 4f76s2(S7/2o8)→601.8154nm4f76s6p(P9/28) transition is 3549.3 (5) MHz. The values of the magnetic dipole constant (A) and the electric quadrupole coupling constant (B) for the 151Eu and 153Eu isotopes for the 4f76s2(S7/208) ground state have been found to be consistent with the values reported by the atomic beam magnetic resonance (ABMR) technique. The hyperfine coupling constants for both the isotopes of Eu for the excited 4f76s6p(P9/28) state are measured to be A(151Eu)=664.73 (9) MHz and B (151Eu)=290 (3) MHz; A(153Eu)=295.15 (7) MHz and B (153Eu)=727 (2)MHz.