“…Here, I,(th) is estimated from eqs. (21)(22), and X C, Xj, + Id,?, where Xj, is the excitation rate of electric dipole-allowed transitions between the ground state and the intermediate 2l-state [32], and I,, is the direct ionization rate from the ground state [31] Then we took the average value of I,, over z as the effective ionization rate coefficient &(exp). In order to examine the reliability of the density determination by the LIF-method in the presence of the plasma, the Ze,-measurements for Zr I were also performed under several plasma conditions in the UV region (& = 296.087 nm, &, = 302.275 nm).…”