  We present experimental inferences of cross-field impurity transport
coefficients for Alcator C-Mod plasmas using a novel forward model for the
entire Ca K-alpha spectrum, including satellite lines within the spectral
range, to compare to high-resolution X-ray Imaging Crystal Spectroscopy (XICS).
These measurements are complemented by Extreme Ultra-Violet (EUV) spectroscopy
that constrains transport closer to the edge. Using new atomic data sets for
both XICS and EUV analysis has enabled consideration of line ratios across both
spectral ranges and has increased the accuracy of inferred transport
coefficients. Inclusion of charge exchange between edge thermal neutrals and
impurities is shown to be extremely important in C-Mod pedestals. We obtain D
atomic neutral densities from experimental D Ly-alpha measurements at the
midplane and compare these to SOLPS-ITER simulations, finding good agreement.
Bayesian inferences of impurity transport coefficients are presented for L-,
EDA H-, and I-mode discharges, making use of the Aurora package for forward
modeling and combining our spectroscopic constraints. Experimentally inferred
diffusion profiles are found to match turbulent transport models at midradius
within uncertainties, using both quasilinear gyro-fluid TGLF SAT-1 and
nonlinear ion-scale gyrokinetic CGYRO simulations. Significant discrepancies in
convection are observed in some cases, suggesting difficulties in predictions
of flat or hollow impurity profiles.
