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 169Tm were measured for the range of velocities, 1.5 ≦ υ/ υ 0 ≦ 6.5. A recent measurement for 156Dy 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 156,158,160Gd, 160,162Dy and 174Yb. 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 152,154Sm, the trend of their g-factors with spin has been derived. We find no strong reduction, at least to spin 10. The 154Sm results are in good agreement with theoretical predictions.