Heliumlike titanium spectra produced by electron-cyclotron-heated tokamak plasmas

We have measured the heliumlike titanium emission lines produced during electron-cyclotron heating (ECH) of Doublet III tokamak plasmas. The spectra observed during ECH at a level of 1 MW show considerable departure from those of ohmically heated plasmas. Theoretical analysis of line intensities shows that the ECH plasma is in disequilibrium with a net state of ionization and relatively little recombination. A departure from the Maxwellian electron distribution is inferred. Electron temperatures deduced from ratios of dielectronic recombination lines to the resonance line (i.e., d₁₃/w, k/w, and j/w) are in significant disagreement with temperatures measured by the Thomson scattering system.