Experiments: Ionizing Plasma

Abstract

In this and next chapters, we review laboratory PPS experiments performed so far. According to the classification in Chaps. 3 and 4, we classify the plasmas into ionizing plasma and recombining plasma. In the present chapter, we review experiments on plasmas belonging to the former class. Low-pressure gas discharge plasmas naturally fall into this class, since, in the stationary state, the ionization flux of atoms in the plasma is balanced with the recombination flux of ions due to the diffusion motion of the ions to the cell wall, not with the CR (collisional-radiative) or volume recombination flux. Another group would be z-pinch plasmas which are formed by strong plasma contraction leading to high temperature and density in a short time. Some laser-produced plasmas have been interpreted as ionizing plasma in the original papers so that they are introduced in this chapter. The magnetically confined plasmas belong to this class and are now becoming the subject of PPS experiments.