Present status and perspective of research on Z pinch plasma focus

Thirty years ago, it was said that Z pinch plasma is unstable and useless. As for recent Z pinch, by flowing the current of more than 1 MA in about 100 ns by using a pulse power generator as the power source, the compression of plasma to smaller than 100 μm diameter has been intended. The plasma at that time is stable, and is in the regions of temperature and density which cannot be treated by the ideal electromagnetic fluid theory. Also by a plasma focus apparatus, the nearly similar results are obtained. The purpose of these devices is to form the plasma of ultrahigh energy density state. The plasma in such state has the possibility of causing electron degeneration by continuing pinch indefinitely. This can be applied to not only nuclear fusion but also to various fields such as the simulation of celestial body plasma, the soft X-ray sources of high brightness and neutron sources. Z pinch and its experiment are explained. The classification of plasma according to its characteristic quantities is shown. Classic Z pinch, plasma focus, the restoration of Z pinch, the various aspects of pinch plasma and the application of pinch plasma are explained. The establishment of International Magnetized High Density Plasma Research Center is being prepared. (K.I.)