European infrastructures for R&D and test of superconducting radio-frequency cavities and cryo-modules

The volume is copyright CERN and can be distributed under CC-BY license. The need for a European facility to build and test superconducting RF accelerating structures and cryo‐modules (SRF test facility) was extensively discussed during the preparation of EuCARD [1,2]. It comprised a distributed network of equipment across Europe to be assessed and, if needed, completed by hardware. It also addressed the quest for a deeper basic understanding, a better control and optimisation of the manufacture of superconducting RF structures with the aim of a substantial improvement of the accelerating gradient, a reduction of its spread and a cost minimisation. However, consequent to EU budget restrictions, the proposal was not maintained. Instead, a more detailed analysis was requested by a sub‐task inside the EuCARD Network [3] AccNet ‐ RFTech [4]. The main objective of this “SRF sub‐task” consists of intensifying a collaborative effort between European accelerator labs. The aim focused on planning and later identifying for European accelerator users a multi‐purpose state‐of‐the‐art network of equipment for R&D and testing of SRF cavities and cryo‐modules. The duration of this sub‐task was agreed to be two years, after which the results were to be presented to the funding agencies. This shall be achieved by this report. This report is inevitably biased by the author’s opinion and preconceptions although a balanced assessment was aimed at. It summarizes the discussions held with individuals and during specific workshops or conferences organized in 2009 ‐ 2011 under the auspices of RFTech [5] and other EuCARD annual meetings [6]. It shall answer the following questions: 1. Is there a need for a SRF test infrastructure, distributed across, and managed by, European accelerator labs? 2. What research topics are important for the future of SRF technology and what priorities should be attributed to them? 3. Is the capacity and available equipment sufficient to cope with the demands of emerging European projects? [1] https://eucard.web.cern.ch/EuCARD/index.html [2] http://esgard‐omia.web.cern.ch/ESGARD‐OMIA/Programme.html [3] https://eucard.web.cern.ch/EuCARD/activities/networks/WP4/ [4] http://accnet.web.cern.ch/accnet/RFTech/ [5] http://accnet.web.cern.ch/accnet/Activity_Reports/2009/RFTech_SRF_videoconference.pdf https://indico.desy.de/conferenceDisplay.py?confId=2831 http://lpsc.in2p3.fr/Indico/conferenceDisplay.py?confId=530 http://indico.cern.ch/conferenceDisplay.py?confId=118190 [6] https://indico.cern.ch/internalPage.py?pageId=7&confId=115634 http://indico.cern.ch/conferenceDisplay.py?confId=118190