The Swedish theoretical physicist leading stellarator theory at the Max Planck Institute for Plasma Physics — whose work on neoclassical transport in optimized stellarators underpins the Wendelstein 7-X programme.
ReviewedLast reviewed: 9 Aug 2026·Category: Scientists & Pioneers
Career
Per Helander is head of the Stellarator Theory Division at the Max Planck Institute for Plasma Physics (IPP) in Greifswald, Germany, and a professor at the University of Greifswald. He previously held positions at Imperial College London and Chalmers University.[1]
Key Contributions
Collisionless confinement in stellarators: Helander has made foundational contributions to understanding particle orbits, neoclassical transport, and bootstrap current in three-dimensional magnetic fields. His work has been essential to validating the quasi-isodynamic optimization of Wendelstein 7-X.
Helander co-authored the authoritative textbook Collisional Transport in Magnetized Plasmas (Cambridge University Press, 2002, with D.J. Sigmar), which is the standard reference for neoclassical transport theory in both tokamaks and stellarators.[2]
Wendelstein 7-X
As head of stellarator theory at IPP, Helander plays a central role in interpreting W7-X experimental results and guiding the optimization of future stellarator designs. His group’s predictions of reduced neoclassical transport in W7-X were confirmed by the landmark 2021 Nature publication.[3]
Sources
Helander, P. and Sigmar, D.J. Collisional Transport in Magnetized Plasmas. Cambridge University Press, 2002.
Helander, P. "Theory of plasma confinement in non-axisymmetric magnetic fields." Reports on Progress in Physics, 77, 087001, 2014.
Beidler, C.D. et al. "Demonstration of reduced neoclassical energy transport in Wendelstein 7-X." Nature, 596, 221–226, 2021.