Level crossing in hyperfine interactions studied by perturbed γ-γ angular correlations

Abstract

The technique of differential ~-7 angular correlation measurements has been applied to an investigation of the hyperfine interactions in the 482 keV level of 181Ta. The activity was embedded in the lattice of a hafnium single crystal. The investigation of the quadrupole interaction gave for the electric interaction frequency ~o0= (313 +_ 4) MHz.The electric field gradient was found to be axially symmetric, the asymmetry parameter being ~/<0.1.Furthermore the combined collinear magnetic dipole and electric quadrupole interaction was studied. The angular correlation was investigated as a function of the strength of the external magnetic field by integral as well as time differential measurements. The integral anisotropy as function of the magnetic field has the shape of a resonance curve. The maximum was observed at a magnetic field of Bres = (24.2 + 0,5) kG.

The Effect of High Pressure on the Quadrupole Interaction of181 Ta in Metallic Hafnium

“…1 with the theoretical least-squares fit (solid lines). Table 1 Table 1 Results from the fitting of the experimental data in Fig (2) urement of the lattice p a r a m e t e r s of hafnium as function of p r e s s u r e is planned in this laboratory.…”