Recombination kinetics of impurities during a major disruption in a tokamak

In the present paper, analysis is made of the bursts of the CV triplet emission observed over all of the viewing chords in high-current discharges. The data obtained by measurements of the spatial and temporal parameters of the CV line emission from the central and peripheral plasma regions in the rapid phase of disruption are compared with the results of calculations of the kinetics of the charge-state distribution of carbon impurity ions, their kinetics being governed by increase in the effective recombination rate during the disruption. Numerical simulations show that the dispersion of the charge-state distribution increases substantially, the fact being attributed to the rapid phase of disruption dominated by the recombination of impurity ions through charge exchange with neutrals