Modeling of a shell-on-shell nozzle and comparison with laser induced fluorescence and interferometry measurements

Summary form only given. Double shell nozzles have provided improved X-ray yields for Z-pinch implosions. Numerical gas flow calculations, including the interactions between the two plumes of a double Argon puff, were performed and are reported here. 2D gas density profiles as a function of time were obtained using the NOZZLE code, which solves the Navier-Stokes equations for the supersonic transient flow all the way from the plenum, including the effects of the gas release valve motion. The results of this numerical calculations are compared with interferometry and laser fluorescence measurements obtained for double shell nozzles used recently for experiments on Double-Eagle, Saturn and Z (see companion papers by B. H. Failor et al. and H. Sze et al.).