JT-60SA Cryostat

base criostato inauguracion

Cryostat Base at Naka site

The Laboratorio Nacional de Fusión (LNF) leads Spanish participation in the “Broader Approach” agreement between the European Union and Japan. The LNF is responsible for the design, and subsequent manufacture, of the cryostat for the JT-60SA device, as part of the commitment of the Spanish government within the Broader Approach agreement.

JT-60SA is a superconducting tokamak that is currently being assembled at the JAEA laboratories in Naka (Japan). Its cryostat consists of a stainless steel vacuum vessel (13.5 m diameter, 16 m high and 485 Tn weight) which provides the vacuum environment (10-3 Pa) needed to limit the transmission of thermal loads to external components at cryogenic temperatures. The cryostat must withstand both external atmospheric pressure during normal operation and internal overpressure in case of an accident. It also serves as support for the complete coil system as well as the tokamak vacuum vessel.

Cryostat main parameters and featurescriostato9

Due to its multi-functional purpose, the cryostat has been divided in two large assemblies: the cryostat base (CB) and the cryostat vessel body cylindrical section (CVBCS).

The manufacture of the CB, which was undertaken by IDESA (Asturias), was completed at the beginning of November 2012. The manufacture of the CVBCS started at the end of 2013 for delivery to Naka in February 2017.


Cryostat Vessel Body Cylindrical Section: lower and upper sectors.

Main highlights:

  • Signature of the Broader Approach: February 2007
  • Signature of the contract for the manufacturing of the CB: July 2010
  • Delivery of the CB: November 2012
  • Signature of the contract for the manufacturing of the CVBCS: November 2013
  • Delivery of the CVBCS, scheduled for February 2017