Identifying suitable materials for building a fusion power plant is a very broad challenge. In addition to managing the radiation environment across the facility, there is a unique set of requirements for anything that faces the plasma directly. For these plasma-facing wall materials, we need to know how they erode (shed material) so that we can figure out how that will affect fusion power output.
In this work by L. Cappelli and colleagues, tungsten sample materials were placed in the power exhaust region of DIII-D and then the erosion of tungsten was measured and compared with simulations. To better establish the material science of this plasma-material interaction, the research team placed an electrical bias on the tungsten. This better reproduces the potential behavior in a fusion power plant, where the particular plasma characteristics determine the electric potential at the wall surface.
While the trend in erosion with applied bias voltage is consistent between experiment and simulation, the simulated erosion is about 5x larger than measured in all cases. As we continue to better understand this process, we improve our physics-based predictive modeling capabilities, which reduces the risk of unexpected behavior in reactor designs.
This work brought together co-authors from M2P2 (France), General Atomics, CEA IRFM, UC San Diego, Auburn University, Sandia National Laboratories, Fusion and Fission at ORNL, and ORAU.
L. Cappelli, et al., Nuclear Materials and Energy 37, 101551 (2023), https://doi.org/10.1016/j.nme.2023.101551
#fusionenergy #materials #tungsten