Velocity dependence of the transient hyperfine field at Pd ions swiftly recoiling through magnetized Fe

The velocity dependence of the transient hyperfine magnetic field manifest at nuclei of Pd108 ions recoiling through magnetized Fe was investigated to a velocity higher than previously examined for the heavier nuclides. The state of interest (21+) was populated by Coulomb excitation using beams of 80-MeV S32 and 180-MeV Ni58 ions and precessed -ray angular distribution measurements were carried out in coincidence with backscattered projectiles. These results, when combined with prior lower-velocity measurements for Pd106, yield a transient field velocity dependence vp, p=0.41±0.15, for Pd isotopes over the extended velocity range 1.74 vv0 7.02 (v0=c137) a result incompatible with a linear velocity dependence. NUCLEAR REACTIONS Pd108 (S32, S 32) Pd108(21+), Pd108 (Ni58, Ni58) Pd108(21+), ES=80 MeV, ENi=180 MeV, enriched target; measured W(,,H) in polarized Fe. Deduced transient field and velocity dependence of PdFe for vc<~0.054.