Determination of the electromagnetic character of soft dipole modes solely based on quasicontinuous γ spectroscopy

We show that the combined analysis of quasicontinuous γ spectra from the (3He,α) and (nth,2γ) reactions gives the possibility to measure the electromagnetic character of soft dipole resonances. Two-step γ-cascade spectra have been calculated, using level densities and radiative strength functions from the (3He,αγ) reaction. The calculations show that the intensity of the two-step cascades depends on the electromagnetic character of the soft dipole resonance under study. The difference reaches 40–100% which can be measured experimentally.