Measurement of ionization rates of Ti ix, Ne vi, Ne vii, and O vi

Abstract

The effective ionization rates of Ti ix, Ne vi, Ne vii, and O vi have been measured with the use of the plasma spectroscopy method in a $\ensuremath{\theta}$ pinch discharge at an electron temperature (50-60 eV) much below their ionization threshold and at an electron density of (\ensuremath{\simeq} 2-3)\ifmmode\times\else\texttimes\fi{}${10}^{16}$ ${\mathrm{cm}}^{\ensuremath{-}3}$. A theoretical analysis of the effective ionization rates showed that excitation ionization is a major contributing process. Theoretical values are in reasonable agreement with experiment.