Jerry W. Hughes is a 🏷️#physicist and deputy head of magnetic fusion experiments at the 📝MIT Plasma Science and Fusion Center, where he has coordinated pedestal physics research since his years on 📝Alcator C-Mod. He is lead author of "Projections of H-mode access and edge pedestal in the SPARC tokamak" (2020).

The 📝pedestal is the narrow ring of steep pressure gradient at a plasma's edge that appears when a tokamak enters 📝H-mode, and it sets the height of everything inside it: raise the pedestal and the whole core profile rises with it, which is why core performance predictions cannot be made without it. Hughes's 2020 paper found a clear window for H-mode access in full-field 📝D-T plasmas using 📝SPARC's 25 megawatts of auxiliary heating, projected a peeling-limited pedestal pressure above 0.3 megapascals at a density near 3 × 10²⁰ per cubic meter, and predicted 📝edge localized modes carrying more than a megajoule apiece — energy the 📝divertor must absorb. Its most useful line is a margin rather than a maximum: even if mitigating those ELMs halves the pedestal pressure, 📝Q > 2 is still projected. All of it is prediction; SPARC has not yet run.