Status and plans for the ILC cryomodule design

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Status and plans for the ILC cryomodule design

• Tom Peterson, Fermilab
• TESLA Technology Collaboration Meeting
• Frascati, 6 December 2005

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TTF cryomodule is our reference
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TESLA-style module information . . .

• http//ilc.desy.de/e627/e634/e730/e745/index_eng.h
  tml
• Links to talks presented by Lutz Lilje, Axel
  Matheisen, W.-D. Mueller, Bernd Petersen, Nick
  Walker, and others at our December 6 - 7, 2004,
  module meeting at DESY
• http//lcdev.kek.jp/ILCWS/
• First ILC workshop, November 13 - 15, 2004 at
  KEK
• http//tesla-new.desy.de/content/index_eng.html
• DESY TESLA page with link to the TESLA Design
  Report and other information including talks and
  posters from the March 2004 ITRP visit

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Sources of Information

• Bernd Petersen, Lutz Lilje, Axel Matheisen, Nick
  Walker, Hans Weise, and others (DESY)
• Carlo Pagani (INFN)
• Terry Garvey (LAL-Orsay)
• Tom Nicol (Fermilab)
• Don Mitchell (Fermilab)
• John Weisend (SLAC)
• TESLA TDR (March 2001)
• And others!

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Some History of Changes in Design Features for
TTF Cryomodule

• Three generations of TTF cryomodule designs
• TTF-I was module 1
• TTF-II was modules 2 and 3
• TTF-III is modules 4 - 8
• TDR called for some significant changes from all
  of the above such as a longer module with 12
  cavities per module
• Next -- TTF III is our baseline design
• X-FEL modules will differ in some details from
  TTF type III
• ILC modules will begin as a few type III
  prototypes, which are essentially type III with
  the quad at 2 K and supported like a cavity
• Planning has begun for the next generation ILC
  module design, type IV, based on the type III
  design

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Features of type III cryomodule

• Allows for fixed couplers
• Invar rod and roller bearings allow cavities to
  remain axially fixed while the 300 mm tube
  shrinks
• Smaller cross section results in standard pipe
  size for outer vessel
• Axial position of last support changed to stiffen
  structure near quadrupole

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Cryomodule III model -- helium vessels in the
vacuum vessel
CAD model based on DESY design imported and
modified by Don Mitchell, Fermilab
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Cryomodule III model -- helium vessels in the
vacuum vessel with input couplers and quadrupole
CAD model based on DESY design imported and
modified by Don Mitchell, Fermilab
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We have a general consensus regarding what needs
changing

• Based largely on TTF experience, but also Jlab
  and others
• Consensus collected by working groups at
  meetings, including but not limited to
• SLAC (14 - 16 Oct 2004)
• KEK (13 - 15 Nov 2004)
• DESY (6 - 8 Dec 2004)
• Snowmass (August 2005)
• SMTF collaboration meeting (5 - 7 Oct 2005)

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Type IV cryomodule will include the following
features from Type III

• 8 cavities per module
• Same cooling scheme and cryogenic system concept
• Same vacuum vessel diameter and 300 mm pipe
  diameter
• Nearly the same pipe locations and arrangement
• Same cavity centerline location relative to
  vacuum vessel
• Same support posts
• Same thermal shields concept, although coupler
  port locations move
• Same cavity support detail (300 mm header as
  structural backbone with cavities held by roller
  bearings and invar rods)
• Same input coupler (at least in terms of mounting
  and interface to vacuum vessel, cavity, and
  thermal shields)

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Helium vessel supports
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Support posts
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Thermal shield installation
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ILC cryogenic system overview

• Saturated He II cooled cavities _at_ 2 K
• Helium gas thermal shield _at_ 5 - 8 K
• Helium gas thermal shield _at_ 40 - 80 K
• Two-phase line (liquid helium supply and
  concurrent vapor return) connects to each helium
  vessel
• Two-phase line connects to gas return once per
  module
• A small diameter warm-up/cool-down line connects
  the bottoms of the He vessels (primarily for
  warm-up)
• Subcooled helium supply line connects to
  two-phase line via JT valve once per string
  (12 modules)

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TESLA cryogenic unit
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Type IV cryomodule will differ from type III in
the following general areas

• Cavity iris-to-iris spacing reduced to 283 mm
• Reduces length from 12.20 to about 11.8 m, get
  0.75 packing
• Slow tuner modified to allow closer
  cavity-to-cavity spacing (could mean switching to
  blade tuner design, but choice still open)
• Fast tuner -- new design
• Quad/corrector/BPM package under center post,
  hung from 300 mm tube, not on rollers (diverging
  from X-FEL)
• Two major module types, one with quad and one
  without

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More differences of Type IV cryomodule from type
III

• Interconnect features modified to accommodate
  input coupler at end of cryostat
• Quad current leads may be new and different, with
  local impact on thermal shields and vacuum vessel
  ports
• Provisions for quad power lead connection at
  center of module
• Some pipe sizes will be increased for lower
  pressure drops with high flow rates -- would like
  to retain long cryogenic unit lengths up to limit
  of 300 mm pipe and cryo plants. Present effort
  includes re-analysis of heat loads, flow rates,
  and cryogenic system thermal process.

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Cavity Interconnect
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Module predicted heat loads
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ILC cryogenic system much larger than TESLA 500

• 8 cryogenic plant locations
• Approximately 5 km spacing
• Each location with 2 cryogenic plants of about
  the maximum size -- each plant equivalent to
  about 24 kW at 4.5 K
• Each plant about 6 MW wall plug power
• ILC cryogenics about 100 MW total

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Module pipe sizes increase
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(Increase diameter beyond X-FEL)
(Increase diameter beyond X-FEL)
(Review 2-phase pipe size and effect of slope)
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Some critical open design issues

• Quad/corrector/BPM package is a major unknown
  right now and goes into the heart of the module
• Tuner details, slow and fast, but especially fast
  tuner
• Vibrational analysis, which will be compared to
  measurements for verification of the model for
  future design work
• Development of module and module component test
  plans
• Verification of cavity positional stability with
  thermal cycles
• Design of test instrumentation for the module
• Robustness for shipping, analysis of shipping
  restraints and loads, shipping specifications
• Active quad movers(?) A complication

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Blade tuner concept
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Other open design issues

• Design for manufacturability, ease of assembly,
  and cost reduction are always considerations
• Part of the type IV design effort will also be a
  consideration of other options
• particularly with respect to quad location and
  support
• but also perhaps with respect to tuners and/or
  other features
• level of effort on these options will be dictated
  by our manpower and schedule.

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Organization of effort

• An international effort
• Need division of tasks to make best use of our
  resources
• Minimize duplication of efforts
• Take advantage of ideas and expertise
• Pursue options with parallel efforts
• Each institution has limited resources
• Work has begun
• Fermilab has organized a group to do type IV
  design, other labs have also expressed interest
  and/or begun

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Type IV probable schedule

• Design module -- 12 - 24 months (2006 - 2007)
• Magnet/BPM package
• Tuners, etc.
• Integrate into module design
• Build and test -- 12 - 18 months (2007 - 2008)
• In addition to module, need module test stand and
  test facility!
• Total 2 to 3 1/2 years, depending on scope of
  work and availability of resources.

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X-FEL Modules

• 100 modules will be industrially produced
• Brings us to the level of manufacturing
  quantities
• Some differences from ILC, but much of module
  design and manufacturing is the same
• Cavity supports, thermal shields, MLI, vacuum
  vessel assembly, internal piping, etc.
• X-FEL experience will be important and valuable
  part of ILC module development
• X-FEL module effort will stay ahead of ILC effort
  
• Remain in close contact and take advantage of
  similar designs, experience, and industrial input
  to design

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After Type IV--gt increasing quantities

• Experience with large quantities of SC magnets
  follows an old engineering rule (factors of 10)
• 1 prototype
• 10 pre-production prototypes
• 100 first production run (X-FEL!)
• Not throw-aways but slower production, still
  making adjustments, relatively large fraction of
  reject/rework
• 1000 full production run
• There are design changes and manufacturing method
  changes at each stage

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Industrialization, impact on design

• As we move to production of quantities of modules
  in industry, the design will continue to change
• Reduction of required labor
• Less costly materials
• Less costly manufacturing of components
• Design for more efficient assembly

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Type IV is not the (final) ILC design

• Test results of types III and IV will teach us a
  lot
• There will be some choices beyond type IV from
  parallel development efforts
• Industrialization will have a significant impact
  on the design
• Type IV is the next step in module design for ILC