Electron-impact excitation of Ti X.

Abstract

The absolute intensities of Ti x spectral lines emitted from a \ensuremath{\theta}-pinch plasma are measured with a 2.2-m grazing-incidence monochromator which is calibrated in situ by using the branching-ratio technique. An electron temperature of 50 eV and an electron density of 2.2\ifmmode\times\else\texttimes\fi{}${10}^{16}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}3}$ of the plasma are determined from the laser scattering. The measured ratios of line intensities are compared with predictions based on the corona model using the excitation rates calculated by a distorted-wave method. It is shown that such a comparison is possible even for line intensities affected by self-absorption provided their optical depth corrections cancel in the ratio. The experimental uncertainty in the measured ratios is estimated to be \ifmmode\pm\else\textpm\fi{}30%. The results show good agreement between experiment and predictions.