Towards the International Linear Collider ILC

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Stony Brook seminar P. Grannis Oct. 5, 2004
Towards the International Linear Collider (ILC)

• There has been much progress in the past few
  years
• In formulating the physics case
• In specifying the accelerator technology
• In establishing an organizational model
• In initiating contacts with government funding
  agencies

The Linear Collider world is a maze of
impenetrable acronyms. If progress is measured
in silly names, the LC is in good shape!
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A Little History
A Possible Apparatus for Electron-Clashing
Experiments (). M. Tigner Laboratory of Nuclear
Studies. Cornell University - Ithaca, N.Y.
M. Tigner, Nuovo Cimento 37 (1965) 1228
While the storage ring concept for providing
clashing-beam experiments (1) is very elegant in
concept it seems worth-while at the present
juncture to investigate other methods which,
while less elegant and superficially more complex
may prove more tractable.
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2001 The Snowmass Workshop participants
produced the statement recommending construction
of a Linear Collider to overlap LHC
running. 2001 HEPAP, ECFA, ACFA all issued
reports endorsing the LC as the next major world
project, to be international from the
start 2002 The Consultative Group on
High-Energy Physics of the OECD Global Science
Forum executive summary stated as the first of
its Principal Conclusions
The Consultative Group concurs with the
world-wide consensus of the scientific community
that a high-energy electron-positron collider is
the next facility on the Road Map. There should
be a significant period of concurrent running of
the LHC and the LC, requiring the LC to start
operating before 2015. Given the long lead times
for decision-making and for construction,
consultations among interested countries should
begin at a suitably-chosen time in the near
future.
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April 2003 Consensus document signed now by
2700 physicists worldwide. http//sbhepnt.physi
cs.sunysb.edu/grannis/ilcsc/lc_consensus.pdf
) (To join this list, go to http//blueox.uoregon.
edu/lc/wwstudy/ )
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Fall 2002 ICFA created the International Linear
Collider Steering Committee (ILCSC) to guide the
process for building a Linear Collider. Asia,
Europe and North America each formed their own
regional Steering Groups (Jonathan Dorfan chairs
the North America steering group).
International Linear Collider Steering
Committee Maury Tigner, chair
Physics and Detectors Subcommittee (AKA WWS) Jim
Brau, David Miller, Hitoshi Yamamoto, co-chairs
(est. 1998 by ICFA as free standing group)
Parameters Subcommittee Rolf Heuer,
chair (finished)
Accelerator Subcommittee Greg Loew, chair
Technology Recommendation Panel Barry
Barish, chair (finished)
Comunications and Outreach Neil Calder et al
Global Design Initiative organization Satoshi
Ozaki, chair (finished)
GDI central team site evaluation Ralph Eichler,
chair
GDI central team director search committee
Paul Grannis, chair
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Technical Review Committee
In Feb. 2001, ICFA charged a Technology Review
Committee, chaired by Greg Loew of SLAC to review
the critical RD readiness issues. The TRC report
in 2003 gave a series of RD issues for L-band
(superconducting rf TESLA), X-band (NLC and GLC),
C-band and CLIC. The most important were the
R1s those issues needing resolution for design
feasibility.
TRC R1 Issues TESLA Feasibility for 500 GeV
operation had been demonstrated, but 800 GeV with
gradient of 35 MV/m requires a full cryomodule
(9 or 12 cavities) and shown to have acceptable
quench and breakdown rates with acceptable dark
currents. X-band Demonstrate low group
velocity accelerating structures with acceptable
gradient, breakdown and trip rates, tuning
manifolds and input couplers. Demonstrate the
modulator, klystron, SLED-II pulse compressors at
the full power required.

• R1 issues pretty much satisfied by mid-2004

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Main elements of physics program (1)
The Higgs will almost surely be discovered by LHC
(Tevatron), but it will remain to determine its
properties is it the SM Higgs, or more
complicated. ILC (International Linear Collider)
will measure mass, width, spin and parity
measure its couplings to all particles measure
self-couplings (determine Higgs potential).
Susy couplings
Accuracy of BR determination in 500 fb-1
approx. errors
Susy Higgs couplings to fermions, WW (ZZ) differ
from SM as Susy parameters change. Precision BR
measurements? new physics required if Susy, BRs
indicate MA
SM value (decoupling limit)
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Main elements of physics program (2)
If SUSY exists, measure the masses, branching
ratios, quantum numbers of the accessible
particles. Precision is much greater at ILC than
LHC. ILC can measure the gauginos, sleptons,
sneutrinos and the LSP.
e.g. can measure neutralino, chargino mass and
mixing matrices, including the CP phases. Is the
origin of B-Bbar asymmetry in the universe in the
Supersymmetric sector? Measuring masses,
couplings/mixing matrices of sparticles allows us
to extrapolate to high energy, probing the
unification scale, and sorting out the origin of
supersymmetry breaking.
Quark/lepton mass evolution
Gauge mass unification
To get these measurements, have to see the
relevant sparticles! Almost surely this will
require more than 500 GeV collisions.
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Main elements of physics program (3)
If not SUSY, search for new phenomena connected
to strong coupling, large extra dimensions etc.
Significance for 1.2 TeV technirho at LHC and LC
at 500, 1000, 1500 GeV. (factor 6 gain in
significance going from 500 ? 1000 GeV.)
significance
Measure the number of extra dimensions
Present 68 S,T limits
Possible measurements at ILC
Likely want to return to the Z pole to measure
precision Z (and W) properties to further
illuminate the new physics.
68 S,T limits at Giga Z at LC location of
precision ellipse gives model info.
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Parameters for the Linear Collider
Based on the physics goals in the consensus
document, a group drew up parameters for the
Linear Collider
Parameters for the Linear Collider September 30,
2003

• Baseline machine
• Ecm continuously adjustable from 200 500 GeV
• Luminosity and reliability to allow ?Ldt 500
  fb-1 in 4 years following the initial year of
  commissioning
• Ability to scan at any energy between 200 and
  500 GeV downtime to set up not to exceed 10 of
  actual data-taking time
• Energy stability and precision below 0.1
  machine interface must allow energy, differential
  luminosity spectrum with that precision
• Electron polarization of at least 80
• 2 intersection regions for experiments one with
  crossing angle to enable gg collisions
• Allow calibration at the Z, but with lower
  luminosity and emittance

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Parameters for the Linear Collider (2)

• Should be capable of Energy Upgrade
• Energy upgrade to approximately 1 TeV
• Luminosity and reliability to allow 1 ab-1 in
  about 3-4 years
• Capability for running at any energy up to
  maximum energy (assume L scales as vs )
• Beam energy and stability as for baseline machine

• Should preserve Options beyond the Baseline
• Ability to double ?Ldt at 500 GeV to 1 ab-1 in
  two additional years
• Ability to collide e-e- up to full energy
• Positron polarization to, or above, 50 from 90
  GeV to max. energy
• Operation at Z pole with L few x 1033 cm-2s-1
  , with positron polarization
• Operation at WW threshold with few x 1033
  cm-2s-1 and dE/E few 10-5 (not demonstrated)
• Ability to collide photons of arbitrary
  polarization states at up to 80 of maximum
  energy, and 30-50 of ee- luminosity

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Linear Collider technologies, specific machine
realizations, and the Technology Recommendation
(ITRP) process (good introduction at
http//www.desy.de/njwalker/uspas/

• rf bands
• L-band (TESLA) 1.3 GHz l 3.7 cm
• S-band (SLAC linac) 2.856 GHz 1.7 cm
• C-band (JLC-C) 5.7 GHz 0.95 cm
• X-band (NLC/GLC) 11.4 GHz 0.42 cm
• (CLIC) 25-30 GHz 0.2 cm
• Accelerating structure size is dictated by
  wavelength of the rf accelerating wave.
  Wakefields related to structure size thus so
  also is the difficulty in controlling emittance
  growth and final luminosity.
• Bunch spacing, train length related to rf
  frequency
• Damping ring design depends on bunch length,
  hence frequency
• So the frequency dictates many of the design
  issues for LC

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Effects of frequency on design
Power lost in structure walls dP/dz - E02/Rs
where Rs is the shunt impedence, E0 peak E
field gradient dV/dz E0/2 Rs f1/2 for normal
conducting surface Rs f-1 for
superconducting thus prefer high frequency for
good efficiency for warm structures and low
frequency for superconducting cavities. Rs also
controls size of beam loading (loss of rf power
as beam bunches along the train are accelerated),
so limits the bunch train length. Q 2p (stored
energy)/(energy lost per cycle) w ws/ dP/dz
(wsstored energy/unit length) Q f-1/2 for
normal conducting Q f-2 for
superconducting. The Q controls the filling time
time to get the energy into the accelerating
structure. Superconducting Q 1010 Copper
structures Q 104 large Q ? high effic. The
inference is that for high Q, high gradient and
low loss, superconducting wants relatively low
frequency normal conducting wants high frequency.
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• Any linear collider requires Energy
  Luminosity
• Electron source
• Positron production
• Pre-injector accelerators
• Damping rings
• Bunch compressor
• rf power source/delivery
• Low level rf for rf control
• Main linacs
• Beam diagnostics BPMs, movers
• Final focus system at IP
• Machine protection system

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LC proposals and Technology Recommendation (ITRP)
in 2004
C-band proposed by a Japanese group (largely
Univ. Tokyo) to minimize risks of X-band. The
maximum conceived energy for C-band is 500 GeV,
but an X-band follower could boost to 1 TeV. The
difficulty in achieving klystrons, modulators,
structures are alleviated. C-band being used
for SPRING8 (xFEL). View this as a
conservative fall back, but given readiness of
X-band design, not considered in detail.
CLIC replace the klystron based power source
with a low energy, high current drive beam. Beam
gymnastics give pulse train compression. Special
cavities couple the power out of the drive beam
and deliver to the high energy accelerated beam.
Collision energy of 3 TeV thought feasible in
30km site. CERN is building CLIC Test Facility
3 to come online 2008. Many issues remain for
proof of design, handling high field gradients,
power transfer efficiency, cost, wakefield
control, emittance preservation Not
considered as possible choice for baseline LC at
this time.
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X-band NLC (SLAC) GLC (KEK) joint RD and
essentially identical designs
Operating gradient 52 MV/m (65 MV/m unloaded)
max. energy 1 TeV can extend to 1.3 TeV at
reduced luminosity Site length 32 km (27.6km
linacs) 2 tunnels (klystrons and linac are
separate ) Main linac acceleration about 106 Cu
structures fed by 11.4 GHz rf damping slots to
remove higher order modes each structure in a
set of 60 tuned slightly differently to decohere
wakefields. Bunch Dt 1.4ns bunches/train
192 train length 267ns rep. rate
120Hz Crossing angle 1st IP 20 mrad Site
power (500 GeV) 200 MW effic. 2.5
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Tesla DESY led collaboration 35 MV/m maximum
gradient, limited by quench limit Design EMAX
0.8 TeV for TESLA site Site length (0.8 TeV)
33 km linac length 30km Single tunnel
(klystrons on surface) 1.3 GHz superconducting
9-cell cavities in cryomodules containing 12
cavities. Bunch Dt 337 ns bunches/train
2820 train length 950 ms Collisions can be
exactly head on as trailing bunches are far
away. Site power 140 MW effic. 23
US study gave paper design of 1 TeV variant, with
some different design choices.
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Getting the energy rf
acceleration of particles
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rf power generation and acceleration

• Modulator converts ac power to dc pulse for
  klystron
• Klystron tube accelerates electrons through a
  set of bunching cavities generate microwave
  pulse for accelerating electrons in output cavity
  (rf power amplifier)
• For X-band, need to shorten the pulse train use
  dual delay lines and rf switching in SLED-II to
  chop and fold rf pulse on itself
• rf pulse injected into set of rf structures on
  the beam line (travelling or standing wave) for
  accelerating particles

rf pulse compression needed for high power,
short bunch X-band, not for SC L-band
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Klystrons
X-band PPM klystrons small but need 4000 with
75 MW pulse power 1.6 ms pulse length permanent
magnet focussing to reduce power
TESLA multibeam klystron Need 572 10 MW pulse
power 1.4ms pulse length Klystron is larger, but
simpler than X-band
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rf pulse compression for X-band (not needed for
L-band)
Stack reflected power to give 4X klystron power
in ¼ time interval. Systems are long, most
expensive subsystem of main linac.
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The Linear Accelerator (LINAC)
Travelling wave structure need phase velocity
c Circular waveguide mode TM01 has vpgt c No good
for acceleration! Need to slow wave down (phase
velocity) using irises. Bunch sees constant
field EzE0 cosf
SC cavity
Room temp Cu structure
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X-band accelerating structures About 106 Cu
structures, with different aperture to detune
wakefields 60 structures in a section mounted
on a girder. Slots couple out higher order
modes. Room temperature. Input power coupler
is simple. Iris size 0.45 cm
rf breakdown observed in earlier structures has
been cured (lower group velocity, better design,
modified coupler)
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TESLA rf cavities 9-cell cavities (ultra-pure
grade Nb, electropolished, baked).
Electropolishing gives much smoother surface than
Buffered Chemical Polishing. 12 cavities in a
single cryostat cryomodule, operated at high
vacuum and 2K. Iris size 3.5 cm
BCP
EP
Making cost effective, high gradient
superconducting cavities, has been the primary
challenge for the cold machine.
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TESLA cryomodules
3 cryomodules (36 cavities) served by one klystron
rf power input couplers are quite complex
transition from room temp. and atmosphere to 2K
vacuum. Extreme care needed to protect Nb
surfaces.
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TESLA rf cavities Cavities reaching 35 MV/m
(suitable for 800 GeV in the TESLA site
footprint) and Q gt 5x109 have been built. Not
operated in cryomodule. Possible cavity redesign
suggested by KEK could increase gradient to
closer to the quench limit, set by critical B
field at surface.

• Recent results from AC70
• First cavity processed in DESY EP facility

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TESLA rf cavities Surface defects cause field
emission some electrons are captured by rf and
accelerated. Not a problem for the beam
emittance, but (a) extra load on cryo-system and
(b) radiation damage to nearby electronics.
Need to limit to 50 nA/cavity to keep within
cryo limit electropolishing helps by factor 10,
but projection to 35 MV/m (I eGRADIENT ) gives
some cause for worry. But annealing of emitters
will occur.
Red BCP Blue EP
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Achieving the luminosity Emittance control like
herding cats is the nearly impossible trick
required for high luminosity
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Low emittance beams are prepared in the damping
rings
Synchrotron radiation in arcs, wiggler sections,
with energy restored by rf damps the transverse
emittances. Very tight control of orbits,
vacuum, and instabilities are required.
X-band damping ring has been built at KEK, and
has shown the desired low emittance.
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TESLA damping rings
The long bunch train in L-band means the damping
ring to hold the full train is 100s of km long.
Fold the bunches into 20 ns spacing to get 17 km
length for damping ring, and put the rings in the
long linac tunnels, with dogbone sections to
turn the beams around. Convert flat beams in
wiggler arcs into round beams in straight
sections to avoid excessive tune shifts. Need
very fast kickers to eject a single bunch without
disturbing the neighbors.
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Electron cloud buildup in positron DR destroys
the low emittance need secondary emission
coefficient at wall of less than 1.3. (similar
effect from ion buildup in electron DR) Problem
is somewhat worse for X-band also affects the
bunch compressor section following the DRs, and
perhaps the final focus.
Needs further RD
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Transverse Wakefields the emittance killer
Wakefields off axis beam sets up electric field
due to induced charges in cavity walls these
cause deflections of tail of same bunch and on
subsequent bunches. Within a single bunch,
betatron oscillation in head of bunch creates a
wakefield that resonantly drives the oscillation
of the tail. Can be cured by BNS energy spread
from head to tail lower energy tail focussed
harder by quadrupoles L-band wakefields 1000x
less than X-band, but energy spread needed for
X-band is only 10x that for SC, but still a
factor 8 less than SLC.
tail
head eqn
head
tail eqn
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Transverse Wakes
Multibunch wakefield
Bunch current generates transverse deflecting
modes when bunches are not on cavity axis Fields
build up resonantly latter bunches are kicked
transversely
Long range wakefield (on subsequent bunches)
cured for X-band by detuning the structures so
that effects cancel at following bunches.
Ultimately the wakefield currents die out. For
TESLA with 337 ns bunch interval, this effect is
naturally smaller.
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Beam alignment
Beam alignment Must align the cavities to a few
m . Quadrupoles to 100 nm final focus elements
to 10 100 nm, and final lens to nm! Natural
thermal, vibration, ground motion takes the beam
out of alignment so must re-establish the gold
orbit. First survey the linac elements to 100 m
level (harder in SC since dont see cavities
inside cryomodules, and have to allow for thermal
contraction). Beam Position Monitors in all
magnets. X-band structure gives beam position to
10 m. Hard to measure beam within the
superconducting cryomodule, so rely on
measurements at the ends. Steer the beam to the
gold orbit detune quads and measure steering
(beam based alignment). Tuning the orbit can be
done semiautomatically by tracking position
drifts in BPMs and fast feedback at IP, so that
invasive tuning can be kept to relatively long
intervals. Aligning final focus is biggest task.
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Beam alignment
Beam alignment systems will be a big deal! Need
reliable, precise BPMs, redundancy, and
well-automated procedure. Alignment of SC
machine is less critical due to large apertures
and smaller wakefield.
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US study of L-band collider
US group made design of 1 TeV SC collider with
several differences Length to allow 1 TeV Space
for helical undulator to give positron
polarization (test underway at SLAC) Allow
positron production at fixed energy (150 GeV) to
allow stable operation for any energy
collisions 2 tunnels Non-zero crossing angle
(desirable to allow measurement of energy,
luminosity profile, polarization before and after
collision) They estimated that cost of this cold
machine is (1.25 ? .10)X that for warm at same
energy Also performed risk and availability
studies
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Superconducting rf at lower gradient has been
used in several HEP applications it is becoming
the rf system of choice for accelerators.
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And superconducting rf is the basis for many new
applications in a broader spectrum of
accelerator-based physical and biological science
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X-band has many applications to non-scientific
uses.
These stem from the smaller size (higher
gradient) of X-band compared the more normal
S-band military radar on airplanes communicati
ons industry medical accelerators food
sterilization semiconductor lithography
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ITRP -------------------- Linear Collider
Technology Recommendation
Barry Barish FALC Meeting CERN 17-Sept-04
Funding Agencies Linear Collider
Executive summary is public http//www.ligo.calt
ech.edu/donna/ITRP_Home.htm
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ITRP in Korea
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Barish Sept. 17, 2004
Evaluating the Criteria Matrix

• We analyzed the technology choice through
  studying a matrix having six general categories
  with specific items under each
• the scope and parameters specified by the ILCSC
• technical issues
• cost issues
• schedule issues
• physics operation issues
• and more general considerations that reflect the
  impact of the LC on science, technology and
  society
• We evaluated each of these categories with the
  help of answers to our questions to the
  proponents, internal assignments and reviews,
  plus our own discussions

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Barish Sept. 17, 2004
Evaluation Scope and Parameters

• The Panels general conclusion was that each
  technology would be capable, in time, of
  achieving the goals set forth in the Parameters
  Document.
• The Panel felt that the energy goals could be met
  by either technology.
• The higher accelerating gradient of the warm
  technology would allow for a shorter main linac.
• The luminosity goals were deemed to be
  aggressive, with technical and schedule risk in
  each case.
• On balance, the Panel judged the cold technology
  to be better able to provide stable beam
  conditions, and therefore more likely to achieve
  the necessary luminosity in a timely manner.

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Barish Sept. 17, 2004
Evaluation Technical Issues

• In general, the Panel found the LC RD to be far
  advanced. The global RD effort uncovered a
  variety of issues that were mitigated through
  updated designs.
• For the warm technology, major subsystems were
  built to study actual performance.
• The KEK damping ring was constructed to
  demonstrate the generation and damping of a
  high-intensity bunch train at the required
  emittance, together with its extraction with
  sufficient stability.
• The Final Focus Test Beam at SLAC was constructed
  to demonstrate demagnification of a beam
  accelerated in the linac.
• As a result, the subsystem designs are more
  advanced for the warm technology.

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Barish Sept. 17, 2004
Evaluation Technical Issues

• In general, the cold technology carries higher
  risk in the subsystems other than the linacs,
  while the warm technology has higher risk in the
  main linacs and their individual components.
• The accelerating structures have risks that were
  deemed to be comparable in the two technologies.
• The warm X-band structures require demonstration
  of their ability to run safely at high gradients
  for long periods of time.
• The cold superconducting cryomodules need to show
  that they can manage field emission at high
  gradients.
• For the cold, industrialization of the main linac
  components and rf systems is now well advanced.

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Barish Sept. 17, 2004
Evaluation Technical Issues

• Many cold technology components will be tested
  over the coming few years in a reasonably
  large-scale prototype through construction of the
  superconducting XFEL at DESY.
• A superconducting linac has a high intrinsic
  efficiency for beam acceleration, which leads to
  lower power consumption.
• The lower accelerating gradient in the
  superconducting cavities implies that the length
  of the main linac in a cold machine is greater
  than it would be in a warm machine of the same
  energy.
• Future RD must stress ways to extend the energy
  reach to 1 TeV, and even somewhat beyond.

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Barish Sept. 17, 2004
Evaluation Technical Issues

• In a superconducting rf structure, the rf pulse
  length, the length of the bunch train, and
  interbunch time interval are all large. This
  offers many advantages.
• The disadvantages are mainly related to the
  complex and very long damping rings, and the
  large heat load on the production target for a
  conventional positron source, which might require
  a novel source design.
• Storage rings are among the best-understood
  accelerator subsystems today, and much of this
  knowledge can be transferred to the linear
  collider damping rings.
• Beam dynamics issues such as instabilities, ion
  effects, and intrabeam scattering have been well
  studied in those machines.

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Barish Sept. 17, 2004
Evaluation Technical Issues

• Achieving design luminosity will be a critical
  measure of the colliders success. A number of
  arguments indicate it will be easier with the
  cold technology.
• The cold technology permits greater tolerance to
  beam misalignments and other wakefield-related
  effects.
• Natural advantage in emittance preservation
  because the wakefields are orders of magnitude
  smaller
• The long bunch spacing eliminates multi-bunch
  effects and eases the application of feedback
  systems.
• This feedback will facilitate the alignment of
  the nanometer beams at the collision point.
• For these reasons, we deem the cold machine to be
  more robust, even considering the inaccessibility
  of accelerating components within the cryogenic
  system.

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Barish Sept. 17, 2004
Evaluation Cost Issues

• The Panel spent considerable effort gathering and
  analyzing all information that is available
  regarding the total costs and the relative costs
  of the two options.
• At the present conceptual and pre-industrialized
  stage of the linear collider project,
  uncertainties in estimating the total costs are
  necessarily large.
• Although it might be thought that relative
  costing could be done with more certainty, there
  are additional complications in determining even
  the relative costs of the warm and cold
  technologies because of differences in design
  choices and differences in costing methods used
  in different regions.

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Barish Sept. 17, 2004
Evaluation Physics Operations Issues

• Several factors favor the cold machine
• The long separation between bunches in a cold
  machine allows full integration of detector
  signals after each bunch crossing. In a warm
  machine, the pileup of energy from multiple bunch
  crossings is a potential problem, particularly in
  forward directions.
• The energy spread is somewhat smaller for the
  cold machine, which leads to better precision for
  measuring particle masses.
• If desired, in a cold machine the beams can be
  collided head-on in one of the interaction
  regions. Zero crossing angle might simplify
  shielding from background.
• But a nonzero crossing angle permits the
  measurement of beam properties before and after
  the collision, giving added constraints on the
  determination of energy and polarization at the
  crossing point.

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Barish Sept. 17, 2004
Evaluation General Considerations

• Linear collider RD affects other scientific
  areas
• the development of high-gradient superconducting
  cavities is a breakthrough that will find
  applications in light sources and X-ray free
  electron lasers, as well as in accelerators for
  intense neutrino sources, nuclear physics, and
  materials science.
• New light sources and XFELs will open new
  opportunities in biology and material sciences.
• The superconducting XFEL to be constructed at
  DESY is a direct spin-off from linear collider
  RD.
• the RD work done for the X-band rf technology
  is of great interest for accelerators used as
  radiation sources in medical applications, as
  well as for radar sources used in aircraft, ships
  and satellites, and other applications.

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Barish Sept. 17, 2004
The Recommendation

• We recommend that the linear collider be based on
  superconducting rf technology
• This recommendation is made with the
  understanding that we are recommending a
  technology, not a design. We expect the final
  design to be developed by a team drawn from the
  combined warm and cold linear collider
  communities, taking full advantage of the
  experience and expertise of both (from the
  Executive Summary).
• Details of the assessment are presented in the
  body of the ITRP report
• The superconducting technology has several very
  nice features for application to a linear
  collider. They follow in part from the low rf
  frequency.

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Statement of Funding Agency (FALC) meeting
9/17/04 in CERN Attendees Son (Korea)
Yamauchi (Japan) Koepke (Germany) Aymar (CERN)
Iarocci (CERN Council) Ogawa (Japan) Kim
(Korea) Turner (NSF - US) Trischuk (Canada)
Halliday (PPARC) Staffin (DoE US) Gurtu
(India) Guests Barish (ITRP) Witherell
(Fermilab Director,) The Funding Agencies
praise the clear choice by ICFA. This
recommendation will lead to focusing of the
global RD effort for the linear collider and the
Funding Agencies look forward to assisting in
this process. The Funding Agencies see this
recommendation to use superconducting rf
technology as a critical step in moving forward
to the design of a linear collider. FALC is
setting up a working group to keep a close
liaison with the Global Design Initiative with
regard to funding resources. The cooperative
engagement of the Funding Agencies on
organization, technology choice, timetable is a
very strong signal and encouragement.
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What comes next?

• ICFA declares that the old names NLC, GLC, TESLA
  are now retired, and the project is to be called
  ILC.
• ILCSC is now setting up the Global Design
  Initiative (GDI), comprised of two parts (GDE
  Effort for up to agency approval and funding
  GDO Organization when agencies take ownership.
• The plan
• A Central Team located at a National Laboratory
  Site, with Director, Chief Accelerator Scientist,
  Chief Engineer and staff initially of 10-15.
• Three regional teams sited in Asia, Europe and
  North America as determined by the regions. Each
  to have a Regional Director who join with the
  Central Team Director, Accel. Scientist and
  Engineer to form an overall directorate.
• Central Team to direct the work and design
  choices.
• Actual design of subsystems to be done in the
  Regional Teams
• Goal is to keep accelerator science strong in
  all regions

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• Tasks of the GDI Phase 1
• Develop the conceptual design based upon the
  superconducting technology (evolve from the TESLA
  design incorporating ideas and RD from all
  regions. Define the basic ILC layout
• Establish the Work Breakdown Structure for the
  ILC construction define work packages in
  sufficient detail to allow a realistic cost
  estimate
• Develop the configuration management procedure
• Map and direct needed RD, engineering studies,
  industrialization programs
• Coordinate the work packages across the Regional
  Teams
• Establish the cost evaluation methodology
• Establish the road map for completion of a
  construction-ready TDR
• Intend to complete CDR in 1-2 years, including
  site requirements, initial cost, schedule plan

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• Tasks of the GDI Phase 2
• Complete a Technical Design Report to allow
  government approval to begin and ground breaking.
  TDR must have full engineering detail, cost and
  schedule information
• Assign tasks to Regional Teams for construction
• Reporting to government, ILCSC etc.
• Maintain contact with physics community, and
  manage experimental program activity

TDR to be complete in 3 years from now,
sufficient to present full proposal to funding
agencies. 2009 Site selection and approval of
international agreements for roles and
responsibilities Final review in light of LHC
initial results Start construction 2010
Dates for phase 2 are obviously not firm!
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Setting up the Central Team Central Team site
proposals from KEK, SLAC, LBL, FNAL, Cornell,
RAL/Daresbury, DESY, BNL, TRIUMF. Host site
expected to provide reasonable space,
infrastructure etc. Committee to evaluate the
site and recommend to ILCSC by January
2005. Director search Expert in accelerator
physics knowledgeable about the LC,
international reputation. Call for nominations
now issued (DPF and DPB announcement 2 weeks
ago). Committee to recommend Director to ILCSC by
January 2005.
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Draft plan for experimental proposals Proposal
from WWS, the physics and detector world wide
group Aims Ensure at least 2 detector
concepts are developed CDR by 2006 Encourage
worldwide RD on essential detector
technologies Interact with GDI on
machine-detector interface issues Set up panels
under the WWS for these three activities would
be transferred to GDI when it is formally
recognized by agencies. Timetable 2004-5
preliminary costing for 2 detectors 2006-7 CDRs
for at least 2 detector designs 2008 form
collaborations (overlap allowed) submit LOI to
GDO Site selection 1 year GDO selects
experiments and asks for TDR
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• Experiment concepts
• SiD silicon tracking, W/Si calorimetry
• John Jaros and Harry Weerts are leading this
  effort
• TPC, scintillation calorimetry
• (variants? Jet chamber tracking, LAr, ?)
• RD consortia now at work on
• vertex detectors
• primary tracking detectors
• calorimeters EMenergy flow, scintillator
  based,
• Hadron scintillator, RPC, GEMs,
• muon detection
• readout and data acquisition
• beam properties energy, polarization,
  luminosity
• gamma gamma collisions
• test beams

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ILC machine design First ILC workshop to be held
in KEK Nov. 13-15 -- invite 120 accelerator
physicists from around the world to review
systems designs for cold LC discuss which
aspects of the TESLA proposal should be kept, and
which need more thought, RD start to work on
dividing RD effort among regions and labs. US
workshop at SLAC Oct. 14 -16. KEK and SLAC have
embraced the new design effort and are
re-organizing to play critical roles. Fermilab
will lead a consortium to build a superconducting
rf test facility (in Meson East) with ANL, J-Lab,
Cornell. Build capability to fabricate and test
superconduncting cavities, cryomodules outside
DESY. DESY, CERN and others won EuroTeV grant
from EU to study beam delivery systems, damping
rings, polarized positron sources, beam
diagnostics, integrated luminosity performance
systems, metrology and global accelerator network
(remote operation). CERN role is critical its
main foci are launching LHC (and its upgrades)
and assuring its own future. RD on CLIC will
continue. However, in recent months, CERN has
increasingly engaged in and supported the move
toward the TeV scale ILC.
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• Conclusion
• Remarkable progress in the past two years toward
  realizing an international linear collider
• important RD on accelerator systems
• definition of parameters for physics
• choice of technology
• start the global organization
• engage the funding agencies in positive dialog
• We arent there yet many hurdles still to be
  cleared before the ILC becomes real (funding,
  site, international organization, detailed
  design, )
• but the hurdles met so far have been cleared
• Continue to work to make the ILC possible