Abstract
This work characterizes the core transport physics of SPARC early-campaign plasmas using the PORTALS-CGYRO framework. Empirical modeling of SPARC plasmas with L-mode confinement indicates an ample window of breakeven (Q > 1) without the need of H-mode operation. Extensive modeling of multi-channel (electron energy, ion energy, and electron particle) flux-matched conditions with the nonlinear CGYRO code for turbulent transport coupled to the macroscopic plasma evolution using PORTALS reveals that the maximum fusion performance to be attained will be highly dependent on the near-edge pressure. Stiff core transport conditions are found, particularly when fusion gain approaches unity, and predicted density peaking is found to be in line with empirical databases of particle source-free H-modes. Impurity optimization is identified as a potential avenue to increase fusion performance while enabling core-edge integration. Extensive validation of the quasilinear TGLF model builds confidence in reduced-model predictions. The implications of projecting L-mode performance to high-performance and burning-plasma devices is discussed, together with the importance of predicting edge conditions.
| Original language | English |
|---|---|
| Article number | 062501 |
| Journal | Physics of Plasmas |
| Volume | 31 |
| Issue number | 6 |
| DOIs | |
| State | Published - Jun 1 2024 |
Funding
The authors would like to thank M. Greenwald for the experimental data used in Fig. 9. This work was funded by Commonwealth Fusion Systems under RPP020, and used resources of the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility located at Lawrence Berkeley National Laboratory, operated (Contract No. DE-AC02-05CH11231), for the PORTALS-CGYRO simulations (CGYRO from main branch with hash 016ac47, PORTALS version 1.0.0). Clusters hosted at the Massachusetts Green High Performance Computing Center were used to perform the PORTALS-TGLF simulations (TGLF from main branch with hash 037b2f0). Alcator C-Mod data used in this work were obtained under DOE Award DE-FC02-99ER54512. ChatGPT-4 and Microsoft Copilot were used to enhance parts of the manuscript for clarity and coherence. The authors would like to thank M. Greenwald for the experimental data used in . This work was funded by Commonwealth Fusion Systems under RPP020, and used resources of the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility located at Lawrence Berkeley National Laboratory, operated (Contract No. DE-AC02-05CH11231), for the PORTALS - CGYRO simulations ( CGYRO from main branch with hash 016ac47 , PORTALS version 1.0.0). Clusters hosted at the Massachusetts Green High Performance Computing Center were used to perform the PORTALS - TGLF simulations ( TGLF from main branch with hash 037b2f0 ). Alcator C-Mod data used in this work were obtained under DOE Award DE-FC02-99ER54512. ChatGPT-4 and Microsoft Copilot were used to enhance parts of the manuscript for clarity and coherence.