ION EXTRACTION FROM GAS CELLS WITH SUPERSONIC JETS FORMED IN LAVAL NOZZLES

The proposed IGISOL setup at Extreme Light Infrastructure - Nuclear Physics (ELI-NP) will generate radioactive ions via photo-fission of uranium targets placed inside a two-chamber gas cell. In the final stages of their extraction from the cell, i.e. between the first and the second chamber of the cell and the exit of the second chamber, the ions are dragged and carried by supersonic gas jets formed at the exit of Laval type nozzles. Computational fluid dynamics (CFD) gas flow simulations have been performed to establish the gas velocity, temperature and pressure distributions that describe the overall behavior of these supersonic jets.