August 27, 2017 to September 1, 2017
RAI Congress Center, Amsterdam, The Netherlands
Europe/Amsterdam timezone

A 2.5 T, 1.25 m free bore superconducting magnet for the Magnum-PSI linear plasma generator

Aug 30, 2017, 3:45 PM
G102-103 Room

G102-103 Room

Regular 15 minutes Oral Presentation B1 - Superconducting Magnets for Fusion Wed-Af-Or22


Hans van Eck (Dutch Institute for Fundamental Energy Research (DIFFER))


The interplay between a nuclear fusion plasma and the reactor wall determines the performance and lifetime of fusion reactors. DIFFER's main experiment Magnum-PSI is the only laboratory setup in the world capable of exposing materials to plasma conditions similar to those of future fusion reactors. The success of the Magnum-PSI experiment depends on the generation of a 2.5 T magnetic field without restricting the diagnostic access and operational aspects of the experiment. This has been achieved with a magnet consisting of five superconducting solenoids wound on a 2.5 m long stainless steel coil former positioned in a cryostat offering a 1250 mm warm bore. A copper stabilized (Cu/Sc.: 8.7) multifilamentary NbTi conductor with a 3.48 mm2 cross section has been used, thus the magnet exhibits a total inductance of 500 H and a stored energy of 15 MJ. This presents some challenge for the protection scheme that has been implemented using a mix of back-to-back cold diodes and an external dump resistor. The coils generate a plateau shaped magnetic field adjustable up to 2.5 T over a distance of 1750 mm between the exit of the plasma source and the end of the target plate, while the distance between the coils allows for 16 room temperature view-ports. Taking advantage of these, the large warm bore provides an excellent access to the experiment for diagnostics and maintenance. The coils are cooled with liquid helium using a re-condensing system operated with cryocoolers, while the magnet system cycles between zero and full field every day. The magnetic stray field is shielded down to 1 mT outside the experimental area by iron walls that flank the magnet. Design, assembly and testing of the magnet system are described, and the Magnum-PSI experiment and its capabilities will be introduced.

Submitters Country The Netherlands

Primary author

Hans van Eck (Dutch Institute for Fundamental Energy Research (DIFFER))


Herman Ten Kate (CERN) Alexey Dudarev (CERN) Tim Mulder (University of Twente (NL)) Alain Herve (University of Wisconsin-Madison (US))

Presentation materials