PHOTOFISSION EXPERIMENTS AT ELI-NP

Three photofission experimental programs are proposed to be carried out with the brilliant gamma beams that will be available at the ELI-NP facility. First, we will measure the absolute photofission cross-sections of actinide targets and will study the energy, mass and charge distributions of fission fragments, as well as of ternary fission. We further propose to measure the angular distribution of photofission fragments. One of the goals is to resolve the fine structure of the isomeric shelf and to observe the clusterisation phenomena in super- and hyper-deformed actinide states. For this, an array of Bragg ionization chambers and an array of thick gas electron multipliers will be constructed. Second, the structure of exotic nuclei produced in photofission will be studied, in particular, isotopes of refractory elements, by developing an ISOL-type facility with an ion-guide, a RFQ ion cooler and a mass separator to separate and transport the isotopes of interest to the measurement stations. Last, we aim at studies of g-factors of short-lived nanosecond isomers since they are difficult to be measured anywhere else. For measurements and studies of the γ decay of excited states in exotic nuclei, we intent to use the detectors of the ELIADE array.