1. WP1: Superconducting Cavity Developments and Tests Walter Venturini Delsolaro Mid Term Review Meeting, 26 September 2012 CATHI Marie Curie Initial Training Network Cryogenics, Accelerators and Targets at HIE-ISOLDE

2. HIE ISOLDE accelerating cavities VCLCL I L~ /4 High Q (low power dissipation) for several MV/m accelerating field Only achievable with a superconducting structure

3. Technologies for SC QWR Bulk Nb with high RRR and EB welds – Available from industry: – High gradients at low dissipated power are easier – Difficulties in operation (microphonics, high RF power needs) Superconducting coatings (mechanical and thermal stability, lower cost) – Electroplating of Pb on Copper (limited to few MV/m due to low B c of lead) – Nb sputtering on copper – Higher performance than lead plating, competitive with bulk Nb at these frequencies and temperatures – Multidisciplinary technology (surface science, vacuum, sputtering, clean room, superconductivity, RF engineering with plenty of training opportunities – Never industrialized on the QWR shape – Several LINAC projects after HIE ISOLDE could profit from an industrialization – Future work opportunities for trained specialists

4. StrippingmetrologyChemistryClean Room AssemblyCoating Rinsing & Clean Room Assembly Insertion in cryostat Cool Down RF Conditioning, RF Measurements Warm Up, Venting

5. WP1 facts and figures TitleSuperconducting Cavity Developments and Tests Activity typeRTD Person -months96 (ESR1: N. M. Jecklin, 36 months; ESR2: I. Mondino, 36 months and ER1: 24 months) Associated PartnersIPN-Orsay, INFN-LNL, SDMS, ZANON, CINEL, CI ObjectivesDevelop techniques to realize and test a Superconducting quarter-wave resonator (QWR) for HIE ISOLDE using the technology of niobium film sputtering over a copper substrate Description of work1. ESR2: Specification and conceptual study of the SC cavity and subsequent realization of the prototype low-beta cavity. 2. ESR2: Setup of the cryomodule test stand and cold tests of the SC cavity (investigation of Q-drop effect). 3. ER1: Development and commissioning of fast digital electronics (FPGA) for the control of the QWR cavities. 4. ESR1: Development and qualification of Niobium thin film sputtering techniques on copper cavities of different betas. DeliverablesD06. Report on the Optimization of the sputtering processes (ESR1) D07. Report on the SC cavity qualification measurements (ESR1) D08. Report on the Operational prototype of the LLRF system (ER1) D09. Report on LLRF tests (ER1) D10. Final report and/or journal publications on the QWR Cavity Dev. and Tests (ESR2)