First petals installed in the ATLAS Inner Tracker Strips Endcap

A major milestone has been reached in the construction of the ATLAS Inner Tracker (ITk), with the installation of the first nine ‘petals’ of the ITk Strips Endcap at DESY in Germany.

Installation began on 14 September, and on 28 September the ninth petal was successfully inserted into one of the endcap structures, marking the launch of the full-scale integration phase. Each wedge-shaped petal is around 60 cm long and carries six silicon detector modules on each side, with elements facilitating electronic, cooling and other infrastructure all mounted on one lightweight structure.

A key part of the ITk detector, the Strips subsystem will feature two endcaps, each containing 192 petals arranged across six disks. The first nine petals that were installed in the endcap were assembled at DESY, with 184 remaining assembled petals due to be integrated. The second endcap is being assembled at Nikhef in the Netherlands, where a further 192 petals will be installed.

Petal by petal, the endcaps are beginning to bloom – bringing the ITk closer to taking its place at the heart of ATLAS to explore the physics of HiLumi LHC.