Analyzing the nature of impurity transport coefficients in tokamaks using the coupled TRANSP-Aurora impurity transport framework

The study details a new framework coupling TRANSP[1] with the impurity transport code Aurora[2],for impurity transport analyses with interpretive runs in TRANSP.The TRANSP-Aurora framework is developed for better deducing impurity distributions,over current TRANSP impurity models,in an evolving fusion plasma discharge.The framework requires providing Aurora with inputs from a TRANSP run including waveforms of NCLASS[3] calculated impurity transport coefficients.Individual impurity charge state distributions are obtained from Aurora by solving the coupled impurity transport equations for these states with atomic data from ADAS[4] database.The net impurity distribution is estimated next and matched with experimental data.The steps are reiterated for different times into the discharge.Agreement between simulated and experimental impurity distributions yield better estimates of impurity transport coefficients,effective charge state,and radiation losses.The framework is applied here for KSTAR and NSTX discharges.

References

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[2]F.Sciortino et al.2021,Plasma Phys. Control. Fusion,63 112001

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[4]H.P.Summers et al.2006,Plasma Phys. Control. Fusion,48 263