Transforming TRANSP with IMAS Interfaces, GPU optimization, and embedded turbulence for predictive simulations*

In this report, the current status of the TRANSP project [https://doi.org/10.11578/dc.20180627.4; https://arxiv.org/pdf/2406.07781] is presented, highlighting three major improvements. First, the implementation of the IMAS interface in TRANSP has been completed, allowing the code to initiate runs directly from the IMAS database. TRANSP now can write outputs to IDSs or use post-processing to convert results into the IMAS format. Several RF modules, including TORBEAM for EC and TORIC6 for IC H&CD, have been integrated using the IMAS interface. The NUBEAM module now also supports the IMAS interface and is ready for coupling with other codes. Second, the GPU optimization of the NUBEAM module has been completed and successfully tested on Perlmutter at NERSC. Utilizing OpenMPI/OpenACC parallelization, the NUBEAM module can be used for between-shot-analyses with a large number of Monte Carlo particles for high-fidelity NBI computations. Third, we have developed interfaces to the T3D (TRINITY) code with the gyro-kinetic GX model for the anomalous transport [https://arxiv.org/abs/2209.06731]. This integration allows for predictive embedded turbulence simulations in TRANSP with self-consistent sources and equilibria. These improvements enhance TRANSP’s efficiency and robustness, enabling faster between-shot analyses and high-fidelity predictive simulations of tokamak plasmas. Additionally, the development of IMAS interfaces creates new opportunities for seamless integration with IMAS-ready modules and direct access to experimental databases in the IMAS format.