Smith, P.A. Akintola, A.E.T. Dumbell, K.D. Ellis, M.J. Hitchen, S. Hornickel, P.C. Jenkins, C.R. Jones, G. Lowe, M. Mason, D.A. May, A.J. McIntosh, P.A. Middleman, K.J. Miller, G. Moss, A.J. Mutch, J. Oates, A. Pattalwar, S.M. Pendleton, M.D. Poynton, J.O.W. Reschke, D. Steder, L. Wheelhouse, A.E. Wiencek, M. Wilde, S. Wilson, J.T.G. JACoW Publishing Geneva, Switzerland 2226-0366 978-3-95450-215-8 10.18429/JACoW-LINAC2022-MOPOGE25 English 212-214 cavity radiation detector cryomodule MMI Contribution to a conference proceedings 2022 2022-09 https://doi.org/10.18429/JACoW-LINAC2022-MOPOGE25 https://jacow.org/linac2022/papers/mopoge25.pdf The Accelerator Science and Technology Centre (ASTeC) is responsible for delivering 88 High Beta (HB) cavities as part of the European Spallation Source (ESS) facility in Sweden. The bulk Niobium Superconducting Radio Frequency (SRF) cavities operate at 704 MHz. They have been fabricated in industry and are currently being tested at Daresbury Laboratory and Deutsches Elektronen-Synchrotron (DESY). They will then be delivered to Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA) Saclay, France for integration into cryomodules. To date 50 cavities have been conditioned and evaluated and 36 cavities have been delivered to CEA. This paper discusses the experiences and testing of the cavities performed to date at both sites