Testing of the Brink–Axel Hypothesis with the HECTOR+PARIS+KRATTA Set-up

摘要

A very first experiment in the field of nuclear structure at the Cyclotron Centre Bronowice (CCB) facility in Kraków, Poland has been performed recently. The medical cyclotron IBA Proteus C-235 located at CCB produces proton beams in the energy range of 70–230 MeV, that can be used for experimental purposes as well. In the reported measurement, the energy of scattered protons at the incident beam energy of 85 MeV and emitted γ rays from the excited 208Pb target were measured in coincidence. During the experiment excitations in the energy region of the Giant Quadrupole and Dipole Resonances, as well as the Pygmy Dipole States were observed. By applying different conditions on the data, spectra corresponding to γ decays of excited states to selected low-lying levels in 208Pb were obtained, allowing a look into the Brink–Axel hypothesis.