1. Princeton Plasma Physics Laboratory, Princeton University 1 , Princeton, New Jersey 08540, USA
2. Department of Applied Physics and Applied Mathematics, Columbia University 2 , New York, New York 10027, USA
3. Department of Mechanical and Aerospace Engineering, Princeton University 3 , Princeton, New Jersey 08540, USA
4. University of California, Los Angeles 4 , Los Angeles, California 90095, USA
5. Plasma Science and Fusion Center, Massachusetts Institute of Technology 5 , Cambridge, Massachusetts 02139, USA
6. Commonwealth Fusion Systems 6 , Devens, Massachusetts 01434, USA
7. Type One Energy 7 , 8383 Greenway Boulevard, Middleton, Wisconsin 53562, USA
8. United Kingdom Atomic Energy Authority, Culham Science Centre 8 , Abingdon, OX14 3DB, United Kingdom