LASER-PRODUCED AND TOKAMAK SPECTRA OF LITHIUM-LIKE IRON, FE23+

Spectra of highly ionized iron were generated in a laser-produced plas ma and a tokamak. In the spectra from the laser-produced plasma new li nes of Fe23+ were observed that were identified as 3s-4p, 3p-4d, and 3 d-4f transitions. The measured wavelengths of these lines were combine d with measurements of the 2s-2p resonance lines measured in the tokam ak plasma and with earlier measurements of n = 2 to n = 3 transitions to yield an improved system of energy levels for Fe23+. The measured w avelengths are compared with ab initio theoretical values calculated w ith a Dirac-Fock code. With the 4f energy levels, which are nearly hyd rogenic, an improved ionization energy of 16 503 000 +/- 1400 cm(-1) ( 2046.11 +/- 0.17 eV) was determined.