Supersonic nozzle jets on Double Eagle-calculations and comparison to experimental data

Summary form only given. We have performed calculations of the hydrodynamics of concentric, supersonic annular nozzles that are used to inject argon shells for X-ray-emitting plasma implosions. We have compared density profiles produced by straight as well as by aerodynamic nozzle configurations. These calculations, done using the MACH2 code, have also been compared with experimental measurements. We show that achieving profiles that are more nearly independent of distance from the nozzle exit is possible only if the aerodynamic designs are used for nozzle pairs. This reduces "zippering" of the subsequent plasma shell implosion. We also show that fine resolution of the nozzle and injection chamber is required to describe the high Mach number gas flow with sufficient accuracy to allow good agreement with laser interferometry measurements. We also discuss the formation of condensed aerosol particles in the low temperature (10 to 30 K) nozzle expansion region.