  2D profiles of electron density and neutral temperature are inferred from
multi-delay Coherence Imaging Spectroscopy data of divertor plasmas using a
non-linear inversion technique. The inference is based on imaging the spectral
line-broadening of Balmer lines and can differentiate between the Doppler and
Stark broadening components by measuring the fringe contrast at multiple
interferometric delays simultaneously. The model has been applied to images
generated from simulated density profiles to evaluate its performance. Typical
mean absolute errors of 30 percent are achieved, which are consistent with
Monte Carlo uncertainty propagation accounting for noise, uncertainties in the
calibrations, and in the model inputs. The analysis has been tested on
experimental data from the MAST-U Super-X divertor, where it infers typical
electron densities of 2-3 $10^{19}$ m$^{-3}$ and neutral temperatures of 0-2 eV
during beam-heated L-mode discharges. The results are shown to be in reasonable
agreement with the other available diagnostics.
