Untersuchung von Hyperfeinstrukturwechselwirkungen im 1274 keV-Niveau des204Pbm durch γγ-Winkelkorrelationsmessungen

The technique of differential γγ-angular correlation measurements has been applied to an investigation of the hyperfine interactions in the 1274 keV level of²⁰⁴Pb^m. Using liquid sources we derived from the interaction with an external magnetic field of 35,2 kgauss for the g-factor g=+0.055±0.003 in agreement with earlier measurements. The investigation of the quadrupole interaction with the statistically oriented electric field gradient of²⁰⁴Pb^m embedded in the lattice of metallic Thallium gave for the electric interaction frequency in the definition ofSteffen andFrauenfelder ω₀₁=(2.23±0.15) MHz. We observed an additional frequency of ω₀₂=(6.91±0.15) MHz. This second frequency is probably caused by crystal imperfections. It vanished when the metal sources were annealed after the cyclotron irradiation. Finally we investigated the perturbation of the γγ-angular correlation of the 912– 375 keV cascade by a combined interaction of the dipole moment of the intermediate 1274 keV state with an external magnetic field and its quadrupole moment with an statistically oriented static electric field gradient. We found good agreement with the theory ofAlder et al. 2.