Search

The staged installation and commissioning of LIPAc is ongoing at Rokkasho Fusion Institute of QST, Japan for validating the low energy section of the IFMIF deuteron accelerator up to 9 MeV. The LIPAc Superconducting Radio Frequency accelerator (SRF) cryomodule is assembled under the responsibility of the EU Home Team, and the assembly work recently started at Rokkasho in March 2019. To fulfil the cleanliness requirements for the assembly process, QST took the responsibility to prepare the infrastructure of a cleanroom and associated devices. In this present paper, the details of the preparation work for the cryomodule assembly made by QST will be presented., Proceedings of the 19th International Conference on RF Superconductivity, SRF2019, Dresden, Germany

CEA is in charge of the 30 elliptical medium and high-beta cryomodules to be installed in the ESS tunnel in Lund, Sweden. Before launching the assembly of the series cryomodules, CEA developed a medium-beta cryomodule technology demonstrator in a collaboration with IPNO, LASA and ESS. This paper briefly presents the cryomodule assembly and summarizes the main results of the high RF power tests performed in 2018 in a dedicated test stand in CEA Saclay. The main ESS requirements were reached: E_{acc} = 16.7 MV/m in cavities, Pforward = 1.1 MW in power couplers, RF pulses length = 3.6 ms at 14 Hz. The piezo tuners efficiently compensated the Lorentz forces detuning and could stabilize the accelerating field better than 1% over the full length of the expected ESS 2.86 ms beam pulse without any LLRF regulation system. Following this successful validation CEA started the assembly of the first ESS medium-beta series cryomodule, Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

The ESS elliptical superconducting Linac consists of two types of 704.42 MHz cavities, medium and high beta, to accelerate the beam from 216 MeV (spoke cavity Linac) up to the final energy at 2 GeV. The last Linac optimization, called Optimus+ [1], has been carried out taking into account the limitations of SRF cavity performance (field emission). The medium and high-beta parts of the Linac are composed of 36 and 84 elliptical cavities, with geometrical beta values of 0.67 and 0.86 respectively. This work presents the latest vertical test results on ESS medium beta elliptical cavity prototypes. We describe the cavity preparation procedure from buffer chemical polishing to vertical test. Finally magnetic probes (Fluxgate) were installed on the cavity to determine magnetic field background during vertical test. The latest vertical test results showed that our cavity design performance are beyond requirements., Proceedings of the 28th Linear Accelerator Conf., LINAC2016, East Lansing, MI, USA