Simulation of imploding Z-pinch loads with quasi two-dimensional models

Summary form only given, as follows. Two major stages can be distinguished in the process of Z-pinch implosion: a run-in phase and a stagnation phase. The first, run-in phase, is characterised by the important role of shock waves and small radiative losses. The second stage is a phase of existence of a dense high temperature pinch. At this stage, the role of radiation is more significant than the role of shock waves. In this work, the first phase is simulated with the help of 2D snow-plow model that allows taking into account the influence of the Rayleigh-Taylor instabilities and the snow-plow stabilization mechanism. The simulation shows that the growth of the RT instabilities leads to the lost of the substantial part of the imploded mass during the acceleration. The fraction of the lost mass is less in case of double gas-puff implosion than in case of single gas-puff implosion due to the presence of the snow-plow stabilization mechanism. The second phase is simulated with the help of quasi 2D model, where all thermodynamic quantities have a fixed radial profile. The initial conditions for the calculations are taken from the results of the 2D snow-plow model calculations. The model allows estimation of K-shell radiation yields. The results of calculations are compared with the results obtained in the experiments on GIT-4 and GIT-12 generators.