Meeting summary (so far, Monday morning) and comments Tom
Peterson, Camille Ginsburg (FNAL), Alex Ratti (LBNL) Crab Cavity
Meeting, CERN, 1-6 Aug 2013
Slide 2
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 2013 2
Slide 3
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 2013 3
Slide 4
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 2013 4
Slide 5
5
Slide 6
6
Slide 7
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 2013 7
Slide 8
8
Slide 9
Alignment systems optical (HEI-ISOLDE) LHC Crab Cavities, 5 Aug
2013 9
Slide 10
Alignment systems stretched wire (SPL) LHC Crab Cavities, 5 Aug
2013 10
Slide 11
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 2013 11
Slide 12
Crab Cavity Interfaces LHC Crab Cavities, 5 Aug 2013 12
Slide 13
Various key constraints have been identified LHC Crab Cavities,
5 Aug 2013 13
Slide 14
SPS cryogenics Krzysztof Brodzinski LHC Crab Cavities, 5 Aug
2013 14
Slide 15
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 2013 15
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 2013 17
Slide 18
Fermilabs SRF pressure vessel standard LHC Crab Cavities, 5 Aug
2013 18
Slide 19
Safety compliance conclusion As a top priority in this project,
we will work closely with CERNs 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 2013 19
Slide 20
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
2013 20
Slide 21
LHC Crab Cavities, 5 Aug 2013 21
Slide 22
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 2013 22
Slide 23
Cryomodule assembly CERN is certainly capable of doing full
cryomodule assembly So is Fermilab Lets 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 2013 23
Slide 24
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 2013
24