Sensitivity of spinI=5/2 perturbed-angular-correlation measurements to combined magnetic-dipole and electric-quadrupole hyperfine interactions

To design, analyze, and interpret perturbed-angular-correlation (PAC) experiments, the theory of the combined nuclear-magnetic-dipole and nuclear-electric-quadrupole interaction is applied. The applications involve polycrystalline sources that contain spinI=5/2 intermediate-quantum-level PAC probes. Frequenciesw _kk , amplitudesa _kk , and perturbation functionsG ₂₂ (t) are calculated for various values of the combined-interaction parameters, , and, wheny=w _L /W _Q is fixed at 30. For relatively large values ofy, the weak shift in them-state energies caused by the electric-quadrupole interaction generally produces a large change in the resulting perturbation function, and the effect is sensitive to the specific values of the parameters, , and. This sensitivity arises because the weak shift inm-state energies produces heterodyning. Moreover, this analysis indicates that PAC measurements of combined interactions in highly-distorted crystals (W _Q 0 and0) can provide potentially more information than previously thought. This analysis strongly suggests that more experimental investigations should be performed on highly-distorted crystals.