Final design of the Switching Network Units for the JT-60SA Central Solenoid

Alessandro Lampasi, Alberto Coletti, Luca Novello, Makoto Matsukawa, Filippo Burini, Giuseppe Taddia, Sandro Tenconi

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This paper describes the approved detailed design of the four Switching Network Units (SNUs) of the superconducting Central Solenoid of JT-60SA, the satellite tokamak that will be built in Naka, Japan, in the framework of the "Broader Approach" cooperation agreement between Europe and Japan. The SNUs can interrupt a current of 20 kA DC in less than 1 ms in order to produce a voltage of 5 kV. Such performance is obtained by inserting an electronic static circuit breaker in parallel to an electromechanical contactor and by matching and coordinating their operations. Any undesired transient overvoltage is limited by an advanced snubber circuit optimized for this application. The SNU resistance values can be adapted to the specific operation scenario. In particular, after successful plasma breakdown, the SNU resistance can be reduced by a making switch. The design choices of the main SNU elements are justified by showing and discussing the performed calculations and simulations. In most cases, the developed design is expected to exceed the performances required by the JT-60SA project. © 2014 Elsevier B.V.
Original languageEnglish
Pages (from-to)342 - 348
Number of pages7
JournalFusion Engineering and Design
Issue number4
Publication statusPublished - 2014
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Civil and Structural Engineering
  • Nuclear Energy and Engineering
  • Materials Science(all)
  • Mechanical Engineering

Cite this

Lampasi, A., Coletti, A., Novello, L., Matsukawa, M., Burini, F., Taddia, G., & Tenconi, S. (2014). Final design of the Switching Network Units for the JT-60SA Central Solenoid. Fusion Engineering and Design, 89(4), 342 - 348.