The Spectrum ArIX and Extended Spectral Classification in ArV to ArVIII and ArX

Spectroscopic observations of a theta-pinch plasma are analysed, resulting in the classification of nearly 200 spectral lines of ArV to ArX. The ArIX data are of particular interest as the observed lines mainly belong to the 2 p 5 3 d -2 p 5 4 f , 5 f , 6 f , and 2 p 5 3 p -2 p 5 4 d , 5 d , 4 s , 5 s and 2 p 5 3 s -2 p 5 4 p transition arrays, for which no information previously existed. 80 new ArIX energy levels are established. Theoretical calculations of atomic energy levels and oscillator strengths aided the identification of spectral lines.