The nuclear magnetic dipole moments of the stable isotopes of europium and the hyperfine structure anomaly

The nuclear magnetic dipole moment of 151 Eu and the ratio of the moments of 151 Eu and 153 Eu have been measured by the new method of resonance in three loops in a short atomic beam. The results are: μ ( 151 Eu) = 3·419 ± 0·004 n.m.; μ ( 151 Eu) / μ ( 153 Eu)= 2·2686 ± 0·0015. The result, taken together with the ratio of the hyperfine structures of europium, gives a hyperfine structure anomaly of (1·0 + 0·23)%. A theoretical value of the anomaly is estimated.