Calibration of the transient magnetic field for rare-earth nuclei in iron: Application to g-factors of high spin states in 152, 154Sm

Abstract A calibration for the transient magnetic field interaction for rare-earth nuclei recoiling through thin iron has been obtained. Time integral spin rotations for states of known g -factors in 169 Tm were measured for the range of velocities, 1.5 ≦ υ / υ 0 ≦ 6.5. A recent measurement for 156 Dy at a very high recoil velocity ( υ / υ 0 = 10.5) has also been incorporated into the calibration. These data indicate that the field becomes nearly constant with velocity for υ / υ 0 ≳ 7. For a fixed range of velocity ( υ / υ 0 ) in ; ( υ / υ 0 ) out = 5.0; 2.0. measurements were made on the 4 + states of 156,158,160 Gd, 160,162 Dy and 174 Yb. Arguments are presented to relate the 4 + g -factors to the previously measured 2 + values, so that these data provide an additional calibration of the field over the rare-earth region. By comparing the spin rotation for low- and high-spin states in 152,154 Sm, the trend of their g -factors with spin has been derived. We find no strong reduction, at least to spin 10. The 154 Sm results are in good agreement with theoretical predictions.