A Swedish startup argues that a redesigned magnetic mirror can solve the plasma-leak problem that shelved the concept decades ago -- and deliver commercial fusion by 2040.
Magnetic mirrors were among the earliest fusion confinement concepts explored in the 1950s and 1960s, but plasma leaking through the open ends proved intractable, and most programs pivoted to closed-field-line devices like tokamaks. Novatron Fusion Group (NFG), founded in 2019 in Stockholm, believes the problem is now solvable. The company's concept -- invented by co-founder and CTO Jan Jäderberg, who holds an M.Sc. in Structural Mechanics from KTH Royal Institute of Technology -- combines an axisymmetric tandem mirror with biconic cusps to create a confinement geometry that uses three layered mechanisms: primary mirror-field magnetic confinement, ambipolar (electrostatic) plugging, and ponderomotive forces from radio-frequency fields.1
NFG is led by CEO Peter Roos, with co-founder Erik Odén serving as chairman. The company secured €3 million in EIC Pathfinder funding from the European Innovation Council and has attracted additional private investment. In 2026 NFG signed a collaboration agreement with Fusion for Energy (F4E), the EU agency responsible for Europe's contribution to ITER, to exchange expertise on mirror-machine confinement and engineering. The company also partnered with Studsvik, Sweden's nuclear services provider, to advance an industrial-scale pilot-plant concept.3
NFG's development plan targets a pilot fusion plant -- Novatron 2 -- in the Stockholm area. A 2026 Nordic study led in part by NFG evaluated potential siting for a fusion pilot plant in the region, positioning Sweden alongside Finland and Denmark as candidate hosts. The company aims for a commercial demonstration around 2040. A peer-reviewed paper published in Nuclear Fusion in 2026 analyzed axial confinement in the Novatron mirror machine, providing independent theoretical support for the concept's stability claims.4
Mirror machines were largely abandoned for reasons that remain physically real: end-loss rates, velocity-space instabilities, and the engineering complexity of tandem-mirror plug coils. Novatron's theoretical work and early experiments are promising but preliminary. The jump from a lab-scale first plasma to a burning-plasma pilot plant is vast, and the company has not yet published sustained confinement data at reactor-relevant parameters. The European policy environment -- particularly the EU's growing fusion strategy -- may provide tailwinds, but the concept must still prove itself against better-funded closed-field competitors.5