Enable Recite

Subscribe options

Select your newsletters:

Please enter your email address:

@

Your email address will only be used for the purpose of sending you the ITER Organization publication(s) that you have requested. ITER Organization will not transfer your email address or other personal data to any other party or use it for commercial purposes.

If you change your mind, you can easily unsubscribe by clicking the unsubscribe option at the bottom of an email you've received from ITER Organization.

For more information, see our Privacy policy.

News & Media

Latest ITER Newsline

  • Manufacturing | Completion of the first vacuum vessel gravity support

    The factory acceptance test on the first ITER vacuum vessel gravity support has been successfully completed at Haneul Engineering in Gunsan, Korea. Under the 8, [...]

    Read more

  • Technology | Hail showers in ASDEX Upgrade for ITER disruption mitigation

    Just before the 2021 Christmas holiday break, the team at the ASDEX Upgrade tokamak successfully fired frozen deuterium pellet fragments into a plasma as part o [...]

    Read more

  • Image of the week | Like a Meccano under the Christmas tree

    Like Erector set or Meccano parts scattered beneath the tree on Christmas morning, components for the ITER Tokamak cover the floor of the Assembly Hall, waiting [...]

    Read more

  • Poloidal field coils | 12 months saved on number two

    Whatever their size or position, the role of the ITER poloidal field coils is to shape and stabilize the plasma inside the vacuum vessel. However, as the plasma [...]

    Read more

  • Divertor dome | Russia delivers a full-scale prototype

    A multiyear qualification program in Russia has concluded with the successful manufacturing and testing of a full-scale divertor dome prototype at the Efremov I [...]

    Read more

Of Interest

See archived entries

A tall accomplishment

12 metres high: the ITER Korea team stands before the full-scale mockup of the 10° vacuum vessel thermal shield inboard section, completed in 2010. (Click to view larger version...)
12 metres high: the ITER Korea team stands before the full-scale mockup of the 10° vacuum vessel thermal shield inboard section, completed in 2010.
Some of the manufacturing processes tested during fabrication of the mockup. (Click to view larger version...)
Some of the manufacturing processes tested during fabrication of the mockup.
The Korean Domestic Agency, in cooperation with Daebong Acrotec, has completed a full-scale mockup of a 10° inboard section of the ITER thermal shield, and tested the main procedures of fabrication including cutting, bending, forming, buffing, welding, and machining.

"We are pleased to report that all the processes for thermal shield manufacture were demonstrated, with the exception of last-stage silver coating," said Wooho Chung, Technical Responsible Officer. "The fabrication of the mockup allowed us to validate the design and manufacturing process for the ITER thermal shield."
Inserted between toroidal field magnets and the vacuum vessel, the ITER thermal shield system minimizes the thermal radiation to the superconducting magnets. Made of stainless steel panels coated with low-emissivity silver, connecting joints (flanges) and cooling pipes welded to the panels, the thermal shield is operated within the range of 80-100 K during plasma operation. Its surface area covers 10,000 square metres; once assembled, it will stand 25 metres at its highest point.

Two thermal shield segments—the outboard segment and the inboard segment—will be manufactured separately by Korea and then assembled to form a full torus shape. As an open structure, each segment is susceptible to distortion caused by cutting, machining or welding. "It is very important to validate all design and requirement parameters before beginning fabrication," stresses Chung. "The tolerance requirements for the joints in particular are very strict."

During the fabrication of the 10° inboard section mockup, each step of the manufacturing process was validated. Panel thickness and distortion were measured after the bending and forming stages; all welds were successfully verified; and the machining processes were tested. One important finding from the mockup fabrication was that the inboard segment is more flexible than expected, making the handling jig essential during fabrication. However, the structural flexibility of individual segment is beneficial for the assembly of the 40° sector.

"We now plan to make another mockup—the thermal shield outboard 10° section—which will be assembled with the inboard section," says Chung. "These mockups will be used in the test of silver electroplating processes."

The detailed design of the ITER thermal shield will be reviewed in 2011. The beginning of fabrication is expected in early 2012.


return to the latest published articles