Advancing SOLPS-ITER validation with TCV L-mode discharges

Abstract This work advances the quantitative validation of SOLPS-ITER against Tokamak à Configuration Variable ( TCV ) ohmic L-mode discharges. It shows that the treatment of the ion parallel heat flux limiter and the assumptions adopted for chemical sputtering result in a consistent explanation for the divertor over-cooling and excessive divertor density predicted by earlier simulations. A systematic heat flux limiter scan highlights that a strong restriction of ion heat conduction significantly reduces both electron T e , t and ion target temperatures T i , t and drives a compensating increase in plasma density n e , t , resulting in an overly cold and dense divertor solution. The availability of new T e and T i measurements along the outer divertor leg of TCV additionally constrains the model and supports the use of a weakly limited ion heat flux to best reproduce experimental observations. Restricting chemical sputtering to only tiles in the immediate vicinity of the strike points suppressed a spurious low-field-side carbon source associated with thermal molecules and significantly improves agreement with two-dimensional C iii emissivity reconstructions. The resulting SOLPS-ITER setup achieves improved agreement across multiple diagnostics simultaneously for upstream, divertor-leg, and target electron density and temperature profiles, as well as for target heat fluxes and radiation measurements.