Meeting summary (so far, Monday morning) and comments Tom Peterson, Camille Ginsburg (FNAL), Alex Ratti (LBNL) Crab Cavity Meeting, CERN, 1-6 Aug 2013

CERN services and capabilities – visits Main workshop and metrology (building 100) – Said Atieh Surface treatment infrastructure (building 118) and sputtering infrastructure (building 252) – Sergio Calatroni Metallurgy and non-destructive testing (building 599) – Gonzalo Arnau Izquierdo, Ignacio Aviles Santillana Vacuum brazing and new E-beam welding machine (building 112) – Said Atieh Cryo-bypass for LHC collimators (building 112) – Said Atieh, Thierry Renaglia LHC Crab Cavities, 5 Aug

CERN services and capabilities – more SM18 (RF test caves, vertical dewars, magnet test facility) – Mathieu Therasse, Torsten Koettig Mechanical measurements lab (building 376) – Michael Guinchard (CERN) SMI2 (magnet assembly and staging area, SPL cavity support structure mock-up) – Arnaud Vande Craen, Rossana Bonomi, Michael Guinchard In summary: truly remarkable fabrication and measurement capabilities, most impressive, and very knowledgeable personnel LHC Crab Cavities, 5 Aug

SM18 Cleanroom areas Cryomodule assembly areas Vertical dewar test cryostats Test caves with cryogenics capable of hosting a full cryostat test including the service module prior to installation into SPS LHC Crab Cavities, 5 Aug

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SPL cryomodule – Rossana Bonomi, Arnaud Vande Craen Several novel features are being studied Support via a double-walled tube through which is placed the input coupler  Input coupler then precisely at the cavity fixed-point Other cavity end supported by bridge to the next cavity Round vacuum vessel but opens via top lid, long O-ring seal LHC Crab Cavities, 5 Aug

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Alignment systems – optical (HEI-ISOLDE) LHC Crab Cavities, 5 Aug

Alignment systems – stretched wire (SPL) LHC Crab Cavities, 5 Aug

CERN Cryomodule Requirements for Crab Cavities – O. Capatina (CERN) This talk by Ofelia provides a good overview of the constraints and requirements Key document is still the Functional Specification LHC Crab Cavities, 5 Aug

Crab Cavity Interfaces LHC Crab Cavities, 5 Aug

Various key constraints have been identified LHC Crab Cavities, 5 Aug

SPS cryogenics – Krzysztof Brodzinski LHC Crab Cavities, 5 Aug

Discussion, possible modifications Supply bypass (4.5 K) around heat exchanger Cool-down return via heat exchanger and pumping line (up to cool-down branch) Optional 4.5 K supply to manifold below cryostats for warm-up and cool-down, to be determined based on operational requirements LHC Crab Cavities, 5 Aug

Crab Cavity Compliance Requirements LHC Crab Cavities, 5 Aug

ASME options ASME pressure vessel code, Section VIII for pressure vessels, has two major divisions  Section VIII, Div 1 is design by rules, most formulas provided although there is some freedom where none apply  Section VIII, Div 2, is design by analysis LHC Crab Cavities, 5 Aug

Fermilab’s SRF pressure vessel standard LHC Crab Cavities, 5 Aug

Safety compliance conclusion As a top priority in this project, we will work closely with CERN’s EN/MME Design Office Team to satisfy CERN safety requirements In detailed follow-up discussions on this topic, we can provide more information about our standards (ASME and our SRF cavity vessel standard), as those may also help to reach a detailed understanding of requirements here LHC Crab Cavities, 5 Aug

Cryomodule for UK 4Rod cavity – Thomas Jones, Shrikant Pattalwar (STFC Daresbury Laboratory, UK) Nice conceptual design of dressed cavity and cryomodule including structure LHC Crab Cavities, 5 Aug

LHC Crab Cavities, 5 Aug

Present direction for cryostat work With three cavity options  Daresbury continues their design for their cavity  US effort looks at common elements for our two cavities, also taking as much as possible from CERN and Daresbury cryostat design work Funding to continue with all three cavities may not be available. If one US cavity is selected for inclusion in a cryostat, US will focus on that design If Daresbury cavity is not continued, we will focus on one US cavity while Daresbury works with the other US support is, unfortunately, still rather uncertain  Hope to have a designer this fall who will assist with CAD modeling details LHC Crab Cavities, 5 Aug

Cryomodule assembly CERN is certainly capable of doing full cryomodule assembly So is Fermilab Let’s see what support Fermilab receives over the next 4 months and prospects for funding beyond that to assess whether assembly at Fermilab remains an option LHC Crab Cavities, 5 Aug

Conclusions (as of Monday morning!) Excellent meeting, well organized, very informative This collaboration definitely has the expertise and infrastructure to accomplish the task of building a crab cavity cryomodule for tests in SPS  Although we all recognize that the funding is uncertain and the schedule for installation into SPS is very ambitious  Close coordination for best use of our resources will be very important Among our next tasks should be to define the dressed cavity safety compliance requirements, since those may move to advanced design stages soon  Niowave will focus on dressed cavity design and construction initially for their SBIR  We need to ensure that those first dressed cavities satisfy all requirements including documentation LHC Crab Cavities, 5 Aug