
Assembly and welding activities for the cryostat top lid began a year ago, in February 2021. At 665 tonnes, the top lid is the second heaviest of all machine assembly components.
"Everything is in place, and within schedule. We just need to do some control and cleaning," explains Guillaume Vitupier, who recently succeeded Anil Bhardwaj as Group Leader for the In-Cryostat, Cryostat Thermal Shield & Auxiliaries Section. In about a week the Indian Domestic Agency, responsible for the procurement, will hand the component over to the ITER Organization—a moment that will mark the conclusion of more than six years of intense work and collaboration between ITER India, cryostat manufacturer Larsen & Toubro Ltd, and the contractor for assembly and welding MAN Energy Solutions.

The top lid is also the most structurally complex of the four sections that make up the ITER cryostat. Curved in three directions like a skull cap, it is strengthened by an array of stiffeners and ribs. Here, from left to right: Dipen Shah, from Indian manufacturer Larsen & Toubro; Guillaume Vitupier, leader of the ITER cryostat group; and Girish Kumar Gupta, ITER cryostat engineer.
Metal contraction, due to the heat generated by the welding process, was another challenge. "We had very good profile control throughout the operation, taking metrology measures every other day to monitor the behaviour of the component."