Radiative strength functions of germanium from thermal neutron capture

Thermal neutron capture gamma rays from germanium have been studied using an internal irradiation facility and a pair spectrometer. Energy and intensity of transitions in four germanium isotopes were determined and their level and separation energies inferred. The separation energies are Sn (71Ge)=7415.95±0.05 keV, Sn (73Ge)=6782.94±0.05 keV, Sn (74Ge)=10 196.31±0.07 keV, and Sn (75Ge)=6505.26±0.08 keV. The E1 reduced strength function, left-angle ΓγiD-1Ei-3A-2/3 right-angle, of these germanium isotopes was found to be (1.8±0.5)x10-9 MeV-3, a value lower than the global average. The M1 strength function left-angle ΓγiD-1Ei-3 right-angle of 74Ge was estimated to be (20±9)x10-9 MeV-3 which agrees with the global average. The average B(E2)bar ↓ of 74Ge using the present thermal data and the previous resonance data from literature was found to be 18±10e2 fm4 MeV -1 which agrees with the value predicted by the Axel-Brink hypothesis