The European Spallation Source, a European flagship for science and innovation, is being built at Lund, in Sweden, with contributions from partners all over Europe. Italy is one of the 13 Founding Members of ESS, and is preparing more than 70 million Euro in-kind contributions through the INFN LNL, LNS and LASA INFN laboratories, the Elettra Synchrotron facility in Trieste, and the CNR.
At the core of this machine is a superconducting accelerator able to accelerate a 62.5 mA proton beam up to 2 GeV to produce neutrons by the spallation process. Italy contributes to different parts of the accelerator complex. The Ion Source and the Low-Energy Beam Transport Line of the linear accelerator have been designed and built at LNS and have been inaugurated on November 15 by Sweden's King Carl XVI Gustaf and Italian President Sergio Mattarella.
Important progress is also being made at LASA, which is in charge for the construction of the Medium Beta Section of the LINAC. This contribution accounts for 36 Medium Beta cavities ready to be installed into the 9 cryomodules assembled by CEA Saclay in France. The first of the Medium Beta Section cavities, the M001, has been successfully welded and treated at the vendor premises and it is now going through its production cycle, to be ready for test in liquid Helium at 2 K early December at DESY. Afterwards the cavity will be shipped to CEA for acceptance test and preparation for assembling into the cryomodule string. Meanwhile, the second and third cavities had been welded. M002 follows M001 very close to be ready for shipping to DESY middle December. The next cavities of the series will be then shipped from the beginning of next year at a rate of two cavities every three weeks.
