CERN Linac4 Drift Tube Linac Manufacturing and Assembly

The manufacturing of the Linac4 Drift Tube Linac (DTL) components has been completed and the assembly of the structures is in its final stages. 3 tanks of 3.9m, 7.3m, and 7.3m, designed to accelerate a 40mA average pulse current H–beam from 3 to 50MeV, are being assembled from 2, 4 and 4 segments of about 2.0m length, containing each from 22 drift tubes at the low energy end, down to only 6 at the high energy end. Due to its peculiar design avoiding adjustment mechanisms on the drift tube, tight tolerances have to be maintained in the production. This paper discusses the assembly stages that are used to achieve the tolerances over the full length of the structures. Metrology results on the assembled DTL Tank1 confirm the required precision.