Seminarium Fizyki Jądra Atomowego
sala 1.01, ul. Pasteura 5
2026-05-28 (10:15) 
prof. Andreas Görgen (University of Oslo, Norwegia)
Studies of nuclear shapes in neutron-rich fission fragments
Neutron-rich nuclei in the mass region around A=100-110 exhibit several interesting phenomena related to nuclear shapes: a rapid onset of deformation at neutron number N=60 for strontium and zirconium, coexistence of near spherical and well-deformed shapes in the transitional region and pronounced triaxiality for slightly heavier molybdenum and ruthenium isotopes. The richness of shape phenomena, and their sensitivity to small changes in proton and neutron numbers, excitation energy, and angular momentum, makes this mass region an ideal testing ground for theoretical nuclear models.
New experimental results will be presented with a focus on lifetime measurements for short-lived excited states for several nuclides in this mass region. Experiments were performed at GANIL using fusion-fission reactions in inverse kinematics, the VAMOS++ magnetic spectrometer for identification of fission fragments, the AGATA spectrometer for detection of gamma rays, and the recoil distance Doppler shift method to measure picosecond lifetimes. The comparison of the resulting electromagnetic transition strengths with both phenomenological and fully microscopical theoretical models provides new insights into the evolution of nuclear shapes throughout this mass region.
New experimental results will be presented with a focus on lifetime measurements for short-lived excited states for several nuclides in this mass region. Experiments were performed at GANIL using fusion-fission reactions in inverse kinematics, the VAMOS++ magnetic spectrometer for identification of fission fragments, the AGATA spectrometer for detection of gamma rays, and the recoil distance Doppler shift method to measure picosecond lifetimes. The comparison of the resulting electromagnetic transition strengths with both phenomenological and fully microscopical theoretical models provides new insights into the evolution of nuclear shapes throughout this mass region.