The TFMC engineering papers are the seven companion publications, mostly in IEEE Transactions on Applied Superconductivity, that record how the 📝Toroidal Field Model Coil (TFMC) was actually designed, built, cooled, powered, instrumented and tested — the working record beneath 📝The SPARC Toroidal Field Model Coil Program (Paper).
The magnet itself is covered by two of them. 📝Dennis Whyte and twenty co-authors published the experimental assessment and model validation (DOI 10.1109/TASC.2023.3332823), comparing what the coil did against what the models said it would; 📝Rui Vieira and fifty-two co-authors published its design, fabrication and assembly (10.1109/TASC.2024.3356571), which is the paper on how the thing was physically made.
Three more cover the infrastructure a magnet cannot be tested without, and which is invisible in every photograph of the result. 📝Ted Golfinopoulos and thirty-nine co-authors describe the superconducting magnet test facility built for it — titled, accurately, "Building the Runway" (10.1109/TASC.2024.3352395). 📝Philip Michael's team describes the cryocooler-based supercritical helium circulation system delivering 600 watts at 20 kelvin (10.1109/TASC.2023.3332266). 📝Vincent Fry's team describes the 50-kiloamp nitrogen-cooled demountable current leads that get power into a 📝cryostat without conducting heat back in (10.1109/TASC.2024.3354237).
The last two are about knowing when something is going wrong. 📝Erica Salazar and eleven co-authors demonstrated fiber-optic 📝quench detection on 📝VIPER cable at the 📝SULTAN facility (10.1088/1361-6668/abdba8), and Geon Seok Lee's team at Lawrence Berkeley National Laboratory, working with CFS's own 📝Charlie Sanabria, demonstrated detection by torsional acoustic wave (10.1109/JSEN.2022.3209143). In a 📝no-insulation coil carrying tens of kiloamps, 📝quench protection is not a subsystem — it is the difference between a test and a loss.
This cluster ends in 2021, with one coil. Its continuation is 📝The Production Magnet Papers, fifteen publications from 2023 onward recording what changes when the object being qualified stops being a single magnet and becomes a production line.
Twenty 📝tesla is the headline. These seven papers are the answer to "how, exactly," and we published all of them.