Advances in TRANSP: modular, modernized and future-oriented code for tokamak plasmas

We report progress in the modernization and improvement of a physics basis of TRANSP [https://doi.org/10.11578/dc.20180627.4], a time dependent equilibrium and transport code. The TRANSP code is used for the interpretive analysis of tokamak discharges, scenario development and experiment planning. The state-of-the-art models for heating and transport are utilized in the code. Recently, many of these models are reimplemented in TRANSP as stand-alone libraries with independent inputs. This effort on TRANSP modernization separates the TRANSP kernel from individual components, simplifies the development, maintenance, debugging and CI. The ITER Integrated Modeling & Analysis Suite (IMAS) is selected as an interface between TRANSP and these components. In this work, we also report successful coupling of TRANSP to the IMAS ITER database with simulations running with input derived directly from the IMAS database. At this time, we demonstrate TRANSP coupling to IMAS for several diagnostics such as interferometer and RF modules such as TORBEAM. Other developments reported in this talk include: (1) progress in the core-edge coupling; (2) impurity transport modeling; (3) performance improvements.