The spallation Neutron Source (SNS) at Oak Ridge National Laboratory in Tennessee, USA, is one of the most powerful proton accelerators in the world with a beam power of 1.4 MW reached in 2018. Now, SNS is preparing an upgrade of the accelerator to even higher beam energy and beam power, and RI Research Instruments has received a contract for the delivery of 30 high beta cavities for this so-called proton power upgrade (PPU) project.
The contract includes the procurement of the necessary niobium, the manufacturing, and the surface preparation and clean room assembly of the cavities to deliver them “ready for cold RF testing”. The schedule foresees procurement of the niobium until May 2019 and first cavity delivery at the end of 2019/beginning of 2020, followed by a series production of the remaining cavities until mid-2020.
Between 2001 and 2004 RI already produced all 109 superconducting 804 MHz 6-cell cavities of the current SNS accelerator. 35 of these 109 cavities were of the low beta type needed to accelerate the protons from low energy of 180 MeV to medium energy of 380 MeV. The remaining 74 were high beta type cavities used to accelerate the protons further to the design energy of 1 GeV. These cavities produced by RI have been in operation at SNS since 2016.
In 2010, for the production of 420 cavities for the European XFEL project at DESY in Hamburg, Germany, RI installed a sophisticated surface preparation and clean room facility for superconducting RF cavities. After the cavity production for XFEL was completed in 2016, these facilities were used for more than 200 additional cavities of the same kind for the LCLS-II project at the Stanford Linear Accelerator (SLAC), USA. Currently, RI is modifying these surface preparation and clean room facilities to allow preparation of somewhat larger cavities for the European Spallation Source (ESS) in Sweden. With this modification, also the SNS cavities can be treated in these facilities and clean rooms.