Charlie Sanabria is an 🏷️#engineer and principal magnet test engineer at 📝Commonwealth Fusion Systems, and lead author of the 2024 Superconductor Science and Technology paper describing PIT VIPER, a 📝high-temperature superconducting cable built for magnets that must be switched rather than held steady.

The distinction is the point. 📝SPARC's 📝toroidal field coils hold a constant field, and the 📝VIPER cable was built for that duty; the 📝central solenoid and 📝poloidal field coils must ramp hard, and a changing field drives losses through 📝REBCO tape that steady-field designs never have to answer for. Sanabria's cable partitions and transposes the tape stacks into insulated copper petals to suppress those losses, inside a steel jacket rated to carry 50 kiloamps while withstanding 1,000 kilonewtons of force per meter and 300 megapascals of pressure. More than four kilometers had been fabricated by the paper's publication. He holds a doctorate in materials science from Florida State University and previously worked at Berkeley Lab on conductor measurement for the Large Hadron Collider upgrade. "The idea was conceived four years ago. Now we have a functioning magnet, manufactured at full scale," he said in 2024. "Similar earlier technological arcs in the magnet world have taken decades."