  The optical diagnostic observing D-alpha line emission along multiple chords
in the boundary region close to the plasma absorber, is recently installed at
the gas dynamic trap. The implemented pattern of viewing lines is suitable for
a tomographic reconstruction of local emissivity profiles, although steps
towards increasing the channel count and extending of angular plasma coverage
must be taken. The optical registration system of a modular design uses
avalanche photodiodes with wideband amplifiers for a large signal dynamic range
and the effective time resolution of 1 mks. The iterative backward projection
technique based on the maximum likelihood principle, demonstrates an acceptable
computation accuracy. Images of plasma evolution in the cross section were
obtained. Tools for the correlation analysis were also developed and first
results of study of the plasma turbulence are presented.
