ILC Baseline Schedule, Milestones, and Decision points

1
ILC Baseline Schedule, Milestones, and Decision
points

• Tom Himel

2
Preface

• There is a large amount of ongoing RD.
• I will concentrate on those aspects which have
  major effects on the ILC design.
• Note that ILC RD, engineering, and
  industrialization are all going on in parallel.
• Ill describe each RD project with its goals,
  explain why it is useful, give its schedule, and
  some results.
• We know many pieces of the schedule, but the
  fully integrated schedule will be developed
  during the EDR.

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Contents

• Preview of Overall Schedule
• Major risk mitigation RD efforts
• Cavity gradient
• Cryomodule at full gradient
• Linac string test
• E cloud, DR kicker
• BDS system test
• Design for High Availability
• Cost reduction RD
• High power RF
• Construction Schedule and overview

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Technically Driven Timeline
2006
2010
2014
2018
Engineer Design
Construction ? Startup
BCD
Begin Const
End Const
RDR
EDR
Detector Install
Detector Construct
Siting Plan being Developed
Site Select
Site Prep
Pre-Operations
All regions 5 yrs
R D -- Industrialization
System Tests XFEL
Gradient
Cryomodule Full Production
August
e-Cloud
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Cavity Gradient Goal

• Current status Nine 9 cell cavities have been
  produced with gradients gt 35 MeV/m. Not
  reproducible and needs several attempts at final
  processing.
• Goal After a viable cavity process has been
  determined through a series of preparations and
  vertical tests on a significant number of
  cavities, achieve 35 MV/m at Q0 1010 in a
  sufficiently large final sample (greater than 30)
  of nine-cell cavities in the low power vertical
  dewar testing in a production-like operation e.g.
  all cavities get the same treatment.
• The yield for the number of successful cavities
  of the final production batch should be larger
  than 80 in the first test. After re-processing
  the 20 underperforming cavities the yield
  should go up to 95. This is consistent with the
  assumption in the RDR costing exercise.

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Cavity Gradient Plan

• There are three main activities which are closely
  coupled and partially progressing in parallel
• This is needed to separate cavity preparation and
  production issues
• 1. Single-cell RD
• Establishing more reliable final preparation
  parameters.
• Focus on the final rinse after EP before HPR.
• E.g. Ultrasound, Short EP (or HF rinse), H2O2
• 2. Tight-loop (Finish in 2008)
• International multi-cell cavity exchange
• 1st round
• Comparison of regional differences in preparation
  and testing
• 2nd round
• Use single-cell results and implement on 9-cell
  cavities.
• 3. Production-like effort (Continues into 2010)
• Monitor ongoing productions
• Esp. XFEL preparation
• Use qualified and new vendors
• Use improved preparation process for an ultimate
  batch of cavities
• A lot of data will be (is already) available by
  the time of the EDR writing

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Cavity Gradient Cost/Benefit

• Optimistic scenario with final batch tight-loop
• Costs 36 MILCU for the RD
• Gives highest confidence about the gradient
  distribution
• This needs to be compared to
• A reduction of the average gradient for the ILC
  from design of 31.5 to 28
• 600 MILCU

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Cavity Gradient Results
2006
2005

• KEK single cell results
• 2005 just learning
• 2006 standard recipe
• 2007 add final 3 µm fresh acid EP
• Note multi-cells are harder than singles

2007
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Module Test Goal

• Intermediate goal
• Achieve 31.5 MV/m average operational
  accelerating gradient in a single cryomodule as a
  proof-of-principle. In case of cavities
  performing below the average, this could be
  achieved by tweaking the RF distribution
  accordingly.
• Auxiliary systems like fast tuners should all
  work.
• Final goal
• Achieve gt 31.5 MeV/m operational gradient in 3
  cryomodules.
• The cavities accepted in the low power test
  should achieve 35 MV/m at Q0 1010 with a yield
  as described above (80 after first test, 95
  after re-preparation).
• It does not need to be the final cryomodule
  design

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Module Test Plan

• Enough good cavities for the cryomodules are
  expected from the cavity gradient program.
  Module assembly plans
• DESY
• 2007 M7 Being tested now. See next slide
• 2007 M8 Probably no slow-down to select best
  cavities
• 2008 M10 could select best cavities from
  several regions
• US funding problems have us behind schedule
  below
• 2007 Assemble a kit of parts from DESY to get
  first assembly experience at FNAL
• 2008 assemble 2 cryomodules from US produced
  parts. Second may be made by selecting the
  best available cavities.
• 2009 build 2 more cryomodules
• Japan
• 2009-10 Build, test, 3 cryomodules

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Module Test Results
DESY
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String Test Goal

• Build 1 RF unit (3 cryomodules 1 Klystron) to
  fully check
• What gradient spread can be handled by LLRF
  system. This test should be done with and without
  beam loading.
• For heating due to high frequency HOMs.
• Amplitude and phase stability.
• Static and dynamic heat loads.
• To partially check
• Reliability
• Dark current
• for degradation or other weaknesses
• The ILC cryomodule is enough different than that
  of the TTF that a new system test is warranted.

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String Test Plan

• Use cryomodules built for module tests and for
  industrialization.
• Do more tests at TTF/FLASH
• XFEL will both be a string test and provide
  costing, contracting and construction
  information.
• Build 1 RF unit at KEK and 1 at Fermilab.
• Do this in a phased manner, starting with smaller
  tests with modules that dont meet specs.
• Full to spec RF unit should work before 1 of
  the final industrial production of ILC
  cryomodules is complete. (2014)
• There will be a larger second phase string test
  to verify quality of the modules going into the
  ILC.

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String test Cost/Benefit

• The risk if we dont do the string test is that
  we will build 1.5 BILCU of cryomodules and then
  discover a design flaw.
• Fixing them all could take years and easily cost
  more than 20 of the original cost.
• If there is a medium risk (25) of this type of
  error then the riskcost 75 MILCU plus the loss
  of a few years in schedule.
• Note the risk would be high 50-100 if not for
  the TTF.
• The planned string tests will cost over 50 MILCU.

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Schedule in Graphical Form
2009
2012
2015
2018
Construction Schedule
Cryomodule Production
RF System Tests
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E cloud Goal

• Ensure the e- cloud wont blow up the e beam
  emittance.
• Do simulations (cheap)
• Test vacuum pipe coatings, grooved chambers, and
  clearing electrodes effect on e- cloud buildup
• Do above in ILC style wigglers with low emittance
  beam to minimize the extrapolation to the ILC.

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E cloud Plan

• Grooved chambers and special coatings are being
  tested in PEP-II and KEK-B straight sections.
• Lots of simulations have been done and
  bench-marked against existing accelerators.
• Still, the long extrapolation leaves us nervous.
• Plans are being developed to test special
  chambers in wigglers in CESR and KEK-B.
• The funding is not yet assured for these more
  definitive tests.
• Schedule is for results in 2009

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E Cloud Cost/Benefit

• If we dont do the RD, there is a high (50)
  risk that we have to build a second e DR at a
  cost of 200 MILCU. Costrisk 100 MILCU
• The first 2 types of RD cost only a few million.
• The costs of the KEK-B and CESR tests are
  difficult to evaluate as they involve the
  dedicated use of the whole ring and it is unclear
  which costs should be accounted to the ILC. The
  scale is 10 MILCU.

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E Cloud Results
SLAC
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BDS System Test Goal

• Build ATF2, a scaled BDS prototype at KEK to
  test
• Optics design including never before done local
  chromatic correction
• Keeping a beam small (35 nm) and stable to a few
  nm for days at a time
• Laser wires
• Intra-train feedback
• BPMs
• High availability power supplies
• Tuning algorithms

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BDS System Test Plan

• ATF2 is already under construction by a
  multi-regional collaboration.
• Will be commissioned in 2009 with optics tests
  done in 2010

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BDS System Test Cost/Benefit

• Cost is 5 MILCU
• Ameliorates a medium (25) risk of having to do a
  major BDS redesign that could lengthen the BDS
  and cost 200 MILCU extra
• Would be a bargain at twice the price

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High Power RF Goals

• The baseline HPRF design is mature and has very
  little risk.
• The RD concentrates on cost reduction
• A Marx modulator to replace the bouncer modulator
• Modified RF distribution system
• Sheet-beam klystron to replace multi-beam
  klystron
• If all are used, the HPRF cost is cut in half.

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Marx Modulator Results
SLAC
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Marx Modulator Results
100kV Output 1400 µsec, Leveled
SLAC
Long term test planned in coming year.
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Modified RF Distribution System Plans
SLAC
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Sheet Beam Klystron Plan

• Build beam tester and klystron by Summer 2008
• The beam tester will validate 3-D beam transport
  simulations and allow a more rapid turnaround for
  electron gun changes
• The klystron will be developed in parallel with
  little feedback from the beam tester. A rebuild
  of the klystron can incorporate design changes
  motivated by the beam tester

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Sheet Beam Klystron Plan
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Americas Site Plan
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Preconstruction Plan for Fermilab
Central Area fits inside the Fermilab boundary
Boundary of Fermilab
Site Characterization of the Central Area can be
done
5.5 km
5.5 km
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Preparing for 2012 Construction Start
2007
2010
2012
Phase 1
Phase 2
Phase 3
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Civil Construction Timeline
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Technically Driven Timeline (reprise)
2006
2010
2014
2018
Engineer Design
Construction ? Startup
BCD
Begin Const
End Const
RDR
EDR
Detector Install
Detector Construct
Siting Plan being Developed
Site Select
Site Prep
Pre-Operations
All regions 5 yrs
R D -- Industrialization
System Tests XFEL
Gradient
Cryomodule Full Production
August
e-Cloud