Larger Cryogenic Pellets Boost Quasi-Steady-State Stored Energy in Wendelstein 7-X
Unintentional variation in pellet size during W7-X experiments revealed a clear positive scaling between pellet mass and achieved stored energy. The result points to inward pellet-cloud transport beyond NGS model predictions and supports testing even larger pellets to improve stellarator performance.
The observed scaling implies that further increases in pellet size or velocity could push W7-X closer to reactor-relevant triple-product values. Next-step experiments will test pellets above the current size range while monitoring edge-localized mode activity and impurity accumulation to determine whether the benefit persists or saturates.
W7-X Team: Injection of pellets 20% larger than the 2025 maximum will raise quasi-steady stored energy by at least 15% within the next experimental campaign if inward transport persists.
Sources (2)
- [1]Primary Source(https://arxiv.org/abs/2609.17751)
- [2]Supporting Source(https://doi.org/10.1088/1741-4326/acf8e2)