Gas puff nozzle characterization using interferometric methods and numerical simulation

One of the source terms of Z-pinch experiments is the gas puff density profile. In order to characterize the gas puff, we have used two interferometrical methods and performed some numerical simulations. The merits of both optical techniques are presented in terms of sensitivity, accuracy, and full time recording. Hence, one technique has been chosen to characterize the gas puff. The computation fluid dynamics (CFD) code (ARES) has been used to simulate the gas flow with the aim of testing its performances. Comparing experimental and numerical data shows off the taking into account of gas viscosity in computations. Given these consistent results, the nozzle geometries can be optimized in order to obtain specific Z-pinch gas puffs and check the computation with the interferometric method. Results obtained with a cylindrical nozzle are presented herein.