A visible spectral survey from the Alcator C-Mod tokamak1This article is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.

Abstract

A visible spectral survey (3675–6744 Å) from the Alcator C-Mod tokamak has been performed using a high-resolution visible spectrometer constructed at the Lawrence Livermore National Laboratory. The Alcator C-Mod deuterium plasma is shown to have visible emission from numerous atomic species and low charge state ions including, D I, B II–III, B V, C II–III, N II–III, O II–IV, F II–III, Ne I, Na X, Al II–III, Si I–II, Cl II–III, Ar I–III, Ar X, Ti I and III, Fe I–III, Cu I, and III, Mo I, and W I. Nearly all of the emission is thought to come from the cooler edge of the plasma including the scrape-off layer, outside of the last closed magnetic flux surface. However, there is at least one example, included here, where intrinsic visible emission persists deeper into the plasma.