OPTIMIZATION OF PHOTO-FISSION FRAGMENT PRODUCTION IN THE ELISOL SETUP AT ELI-NP

Within the ELI-NP (Extreme Light Infrastructure-Nuclear Physics) project developed in Magurele, Romania, an IGISOL (Ion Guided Isotope Separator On Line) facility is being designed in which exotic nuclei will be produced by the photo-fission of thin uranium foils then extracted and measured. The targets will be placed in a Cryogenic Stopping Cell (CSC) filled with He gas, in which the fission fragments will be thermalized and extracted, using both electric fields and gas flow. The optimization of the target system, aiming at maximizing the rate of ions released in the CSC gas, determining the optimum thickness, geometry and tilting angle of the targets and the optimum gamma beam energy range, is reported.