International Linear Collider Technical Review Committee

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• International Linear ColliderTechnical Review
  Committee
• Nick Walker (DESY)

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Where is The Report?
Available online
http//www.slac.stanford.edu/xorg/ilc-trc/2002/200
2/report/03rep.htm
Printed and CD-ROM versions should be available
soon (now?) 420 pages!
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History of the ILC-TRC

• International Collaboration for RD toward
  TeV-Scale e e LC asked for first ILC-TRC in
  June 1994
• ILC-TRC produced first report end of 1995
• 2001 ICFA requests that ILC-TRC reconvene to
  produce a second report (subject of this talk)

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Second ILC-TRC Charge

• To assess the present technology status of the
  four LC designs at hand, and their potential for
  meeting the advertised parameters at 500 GeV c.m.
• Use common criteria, definitions, computer codes,
  etc., for the assessments

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Second ILC-TRC Charge

• To assess the potential of each design for
  reaching higher energies above500 GeV c.m.
• To establish, for each design, the RD work that
  remains to be done in the next few years
• To suggest future areas of collaboration

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LC Status at First TRC
1994 Ecm500 GeV
TESLA SBLC JLC-S JLC-C JLC-X NLC VLEPP CLIC
f GHz 1.3 3.0 2.8 5.7 11.4 11.4 14.0 30.0
L?1033 cm-2s-1 6 4 4 9 5 7 9 1-5
PbeamMW 16.5 7.3 1.3 4.3 3.2 4.2 2.4 1-4
PAC MW 164 139 118 209 114 103 57 100
gey?10-8m 100 50 4.8 4.8 4.8 5 7.5 15
synm 64 28 3 3 3 3.2 4 7.4
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LC Status at Second TRC
2003 Ecm500 GeV
TESLA SBLC JLC-S JLC-C JLC-X/NLC VLEPP CLIC
f GHz 1.3 5.7 11.4 30.0
L?1033 cm-2s-1 34 14 20 21
PbeamMW 11.3 5.8 6.9 4.9
PAC MW 140 233 195 175
gey?10-8m 3 4 4 1
synm 5 4 3 1.2
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Organisation
Chair Greg Loew (SLAC)
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Organisation
Chair Greg Loew (SLAC)
Steering Committee
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Technology Working Group
ChairDaniel Boussard (CERN) MembersC. Adolphsen
(SLAC)H. Braun (CERN)H. Edwards (FNAL)K.
Hubner (CERN)L. Lilje (DESY)P. Logatchov
(BINP)R. Pasquinelli (FNAL)M. Ross (SLAC)T.
Schintake (KEK)N. Toge (KEK)H. Weise (DESY)P.
Wilson (SLAC)

• Injector, DR, and BDS
• Power Sources
• klystrons, power supplies, modulators, low level
  RF etc.
• Power Distribution
• RF pulse compression, waveguides, two-beam
  acceleration (CLIC) etc.
• Accelerator Structures

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Luminosity Working Group
ChairGerry Dugen (Cornell) MembersR. Assmann
(CERN)W. Decking (DESY)J. Gareyte (CERN)K.
Kubo (KEK)W. Kozanecki (Saclay)N. Phiney
(SLAC)J. Rogers (Cornell)D. Schulte (CERN)A.
Seryi (SLAC)R. Settles (MPI)P. Tenenbaum
(SLAC)N. Walker (DESY)A. Wolski (LBNL)

• e Sources (gun ? DR)
• DR
• Low Emittance Transport (LET, from DR ? IP)
• bunch compressors
• main linac
• beam delivery
• Machine Detector Interface

Many new studies (simulations) performed THIS was
much more than a review!
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Reliability Working Group
Co-ChairsRalph Pasquinelli (FNAL)Nan Phinney
(SLAC)
MembersC. Adolphsen (SLAC)Y. Chin (KEK)H.
Edwards (FNAL)K. Hubner (CERN)L. Lilje
(DESY)M. Ross (SLAC)N. Toge (KEK)H. Weise
(DESY) R. Assmann (CERN)W. Kozanecki (Saclay)D.
Schulte (CERN)A. Seryi (SLAC)P. Tenenbaum
(SLAC)N. Walker (DESY)

• Reliability
• hardware components
• MTBF
• Availability
• fraction of time available for delivering
  luminosity
• Operability
• impact of (invasive) tuning, machine studies etc.

technology
luminosity
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2nd TRC Time-Line

• Summer 2001 ICFA requests report
• Autumn 2001 WGs formed
• 2002 WGs meet 4 times during the year to
• define tasks
• review progress
• formulate summary
• October 2002 Greg Loew formally reports findings
  at ICFA seminar
• January 2003 Published!

Many many video/telephone conferences (Tbytes of
email!)
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Methodology

• Review current designs and status (achievements)
  of RD, particularly the test facilities
• Identify the positive aspects of the designs
• Identify those areas of concern and
• identify RD that needs to be done to address
  these issues
• Categorise (rank) the RD items

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The Rankings for RD

• Ranking 1
• Ranking 2
• Ranking 3
• Ranking 4

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The Rankings for RD

• Ranking 1
• Ranking 2
• Ranking 3
• Ranking 4

RD needed for feasibility demonstration of the
machine
what you must do before you can honestly say the
machine will work (proof of principle)
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The Rankings for RD

• Ranking 1
• Ranking 2
• Ranking 3
• Ranking 4

RD needed to finalize design choices and ensure
reliability
Still critical RD, but not central to proof of
principle Not mandatory before formal proposal
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The Rankings for RD

• Ranking 1
• Ranking 2
• Ranking 3
• Ranking 4

RD needed before starting production of systems
and components
Necessary engineering (prototyping) before (for
example) transferring to industry (mass
production)
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The Rankings for RD

• Ranking 1
• Ranking 2
• Ranking 3
• Ranking 4

RD desirable for technical or cost optimisation
Would be useful to do but is not strictly
mandatory Basically all things that fell off
the list for R1-3
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Rankings Score Sheet
TESLA TESLA JLC-C JLC-X/NLC JLC-X/NLC CLIC CLIC Common
Ecm 500 800 500 500 1000 500 3000
R1 0 1 2 2 0 5 2 0
R2 7 4 2 3 0 6 2 8
R3 10 3 3 11 0 5 0 19
R4 1 0 1 2 2 0 0 8
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The Specific R1 Items

• TESLA
• JLC-C
• NLC/JLC-X
• CLIC

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The Specific R1 Items

• TESLA
• JLC-C
• NLC/JLC-X
• CLIC

• Ecm 800 GeV Building and testing of a
  cryomodule at 35 MV/m and measurements of dark
  current

• Requires the module test stand
• Delayed by budget constraints
• Very unlikely to happen before 2005!

However, the push to Ezgt35 MV/m continues
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TESLA High-Gradient RD

• High gradients good for X-Ray FEL too

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TESLA High-Gradient RD

• High gradients good for X-Ray FEL too
• Electro-polishing programme on-going and
  considered best for mass-production

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TESLA High-Gradient RD

• High gradients good for X-Ray FEL too
• Electro-polishing programme on-going and
  considered best for mass-production
• Fast piezo cavity tuner to compensate Lorentz
  force detuning

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The Specific R1 Items

• TESLA
• JLC-C
• NLC/JLC-X
• CLIC

• Ecm 500 GeV High power tests of of C-band
  choke-mode and dark current
• Ecm 500 GeV Demonstration of SLED-II pulse
  compressor at full power

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The Specific R1 Items

• TESLA
• JLC-C
• NLC/JLC-X
• CLIC

• Ecm 500 GeV Test of complete accelerator
  structure at design gradient with detuning and
  damping, including study of breakdown and dark
  current
• Ecm 500 GeV Demonstration of SLED-II pulse
  compressor at full power

Goal end of 2003 for proof of principle tests
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The Specific R1 Items

• TESLA
• JLC-C
• NLC/JLC-X
• CLIC

• Test existing structures at 130ns pulse length
  and design gradient.
• High power tests of structures with wakefield
  damping
• design and test of switchable power extraction
  transfer structures
• Validation of drive beam generation with fully
  loaded linac
• full test of a basic hardware unit (at reduce
  length)

Many basic questions as expected for an RD
project
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The R2 Items

• Damping Rings
• Electron cloud effects
• fast ion instabilities
• Extraction kicker stability
• Tuning simulations
• LET
• Static tuning studies
• girder/cryomodule prototypes to study stability
  (vibration)
• Critical beam instrumentation
• Reliability
• Detailed evaluation of critical sub-systems
  reliability

Common items related to all designs
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TESLA R2

• Test of complete main linac RF sub-unit(as
  described in TDR) with beam
• Tests of several cryomodules running at gradient
  23.4 MV/m for a prolonged period of time
• quench rates, breakdowns, dark current

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TESLA R2

• Test of complete main linac RF sub-unit(as
  described in TDR) with beam
• Tests of several cryomodules running at gradient
  23.4 MV/m for a prolonged period of time
• quench rates, breakdowns, dark current

• One versus two tunnels (reliability)
• DR dynamic aperture
• wiggler end fields
• need to minimise injection losses (Pinj220kW)
• DR kicker development
• Head-on versus crossing angle
• extraction lines issues

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JLC-X/NLC R2

• Test of complete X-band main linac RF sub-unit
  (as described in baseline design) with beam
• Full test of KEK 75 MW 1.6ms PPM klystron at
  150/120 Hz
• Full test of SLAC induction modulator

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8-Pack Project

• Used 4??50MW klystrons
• Drive NLC ready structures in NLCTA
• End 2003

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R3

• To some extent fine tuning R2 requirements
• Much detailed work which (eventually) must be
  done
• Examples (TESLA)
• Backgrounds and collimation
• Impact of positron scheme on commissioning/operabi
  lity
• LLRF (needs to be robust)
• single tunnel noise sources

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The Positive Side
Rankings reflect the concerns of the working
groups But TRC overall findings were extremely
positive
The ILC-TRC
did not find any insurmountable obstacle to
building TESLA, JLC-C, JLC-X/NLC within the next
few years
executive summary
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The Positive Side
Rankings reflect the concerns of the working
groups But TRC overall findings were extremely
positive
The ILC-TRC
also noted that the TESLA linac RF technology
for 500 GeV c.m. is the most mature.
executive summary
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The Positive Side
Rankings reflect the concerns of the working
groups But TRC overall findings were extremely
positive
The ILC-TRC concluded that
Assuming the R1s are demonstrated (hopefully) by
the end of 2003, the RF systems of the two
machines will be on an equal footing
executive summary
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The Positive Side
Rankings reflect the concerns of the working
groups But TRC overall findings were extremely
positive
The ILC-TRC concluded that
At that time, the HEP community should make a
choice based on the technical differences of the
two machines reflected by the R2 issues
executive summary
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The Manpower Money Problem
The R1-4 issues are important but they need money
and manpower to resolve
The TESLA collaboration has limited
(sub-critical) resources to address the R2 items
(not related to the linac technologies) on any
immediate time scale
X-FEL has linac technology in hand
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Final Comments

• The TRC is a excellent example of what we can
  achieve when the LC accelerator communities work
  together
• Attempts to maintain the momentum post TRC are
  dwindling
• Need guidance (mandate?) from ILCSC and the
  support of lab management to continue this
  collaborative work
• Need More People!