Measurement of Dielectronic Recombination Rates for the Iron Ions Fe IX-XI

Abstract

Iron is injected into a well-diagnosed $\ensuremath{\theta}$-pinch plasma. The intensities of lines from various ionization stages are measured as functions of time and interpreted by means of a time-dependent corona ionization-recombination model. Effective coefficients for dielectronic recombination at electron densities ${N}_{e}\ensuremath{\approx}3\ifmmode\times\else\texttimes\fi{}{10}^{16}$ ${\mathrm{cm}}^{\ensuremath{-}3}$ are equal to or smaller than presently accepted theoretical values for low-density plasmas. Rate coefficients for ionization tend to be smaller than theoretical values.