A one-dimensional radiation magneto-hydrodynamics code coupled to an
atomic kinetics code was developed,
whose simulation results were compared with the experimental
Based on the simulation results, the physical processes and physical scheme of
Z-pinch implosions were studied. During the implosion phase,
the plasmas are heated and ionized, and before the stagnation,
the greatly ionized plasmas of high temperature and high
density are created. Then the continuously rising density leads to
the recombination of plasmas and the emission of an intense
Our simulation shows that there are two necessary conditions for
producing high yield of K-shell energy.
Firstly, highly ionized plasmas must be prepared before
the beginning of recombination.
Secondly, the density of the plasmas which are in recombination phase
should be high enough to make the plasmas recombine
with a large rate so that more
internal energy can be drawn before stagnation.
As another result of our study, the atomic processes play a role in cooling
free electrons during the recombination phase.