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Evaluates the effect of wall reflections on H-alpha emission at Alcator C-MOD tokamak. Modeling of the H-alpha emission with the DEGAS 2 code; Reflection coefficients.

Observations of spectral line profiles commonly represent the integration of emission along the line of sight. Depending on the number of views and the symmetries involved, one can use techniques ranging from simple Abel inversion to complex tomographic reconstruction to find the spatial distribution emitters. In tokamak experiments, the spatial dependence of the magnetic field is typically available and can be used to gain important insights into the absence of other spatial information. The Zeeman patterns of spectral lines from neutral atoms and low-Z ions in tokamak plasmas can contain enough information to restrict the location of emission to well defined positions along a given line of sight. Simple modeling of observations with high spectral resolution from Alcator C-Mod plasmas demonstrates the application of this technique to the interpretation of experimental data. This localization of emission is not only of interest to spectroscopists and modelers of tokamak edge and divertor regions, it could be used to aid the operation of other visible-light diagnostics that seek spatial resolution. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]