While concrete pouring was underway last Wednesday on the last segment of the Tokamak Complex basemat, laser measurements were still being performed on a large circular steel ring, deeply anchored at the very centre of the plot.

Laser measurements on the circular steel ring were still being performed while concrete pouring was underway last Wednesday.

 Topped by a temporary, blue steel structure designed to prevent deformation, the steel ring is part of the support system for the huge inner support column—the steel backbone that, along will seven radial beams, will stabilize the vacuum vessel sectors during the first stages of machine assembly.

 Because it was vitally important that the circular ring and its four associated inserted plates remain perfectly positioned, the temporary steel structure guaranteed the ring's rigidity during the pour and regular laser surveys ensured that no deviation had occurred from the original position.

The inner support column will form the axis and backbone of the Tokamak during the first phase of machine assembly.

During first-phase Tokamak assembly operations, the inner support column will form the axis of the Tokamak. Once the nine sectors of the vacuum vessel are assembled and welded, the column will be removed from the machine and the central solenoid will take its place.

 Last Wednesday, as ITER celebrated the "Final Pour" of the Tokamak Complex basemat, the first element of an assembly tool was in place, ready for an operation that should begin in 2017.