The International Linear Collider Accelerator R&D Program

The International Linear ColliderAccelerator R&D Program

Steve HolmesFermilab Associate Director for Accelerators

EPP2010May 16, 2005

Page 2EPP2010, May 16, 2005 – S. Holmes

Outline

• ILC Orientation

• Technology Requirements and Challenges

• Risk Elements

• R&D Program

• Fermilab Perspective

• Summary


ILC OrientationWhat is it?

A facility for providing electron-positron collisions at sufficient energy and luminosity to afford access to the physics frontier at and beyond LHC.

Requirements:

– Energy = 500 GeV, extendible to 1000 GeV

– Luminosity ~ 21034 cm-2sec-1 (500 fb-1 in the first four years)

How? 7 nm

250 GeVe+

250 GeVe-

308 ns


ILC OrientationWhat does it look like?

Major Components:– Sources: Provide particles

( e+ generated by electrons)

– Damping Rings: Reduce emittance

– Bunch Compressors: Reduce bunch length

– Linac: Accelerate

– Beam Delivery/Final Focus: Prepare, focus, and collider

– Detector(s): Observe

Length = 40-50 km


ILC Orientation International/National Scene

• The International Linear Collider has received strong endorsement by HEPAP, and corresponding advisory committees in Europe and Asia, as the next forefront EPP facility beyond LHC.

• ILCSC established and functioning– Under auspices of ICFA– Charge: Promote construction of a linear collider through world-wide

collaboration– Global Design Effort (GDE) established: B. Barish/Director

• USLCSG established and functioning. – Charge: Coordination of U.S. R&D activities;– Preparation of the U.S. bid to host

• Identification of LC as highest mid-term priority in the Office of Science 20-year plan


ILC OrientationWorking Parameter Set

Center of Mass Energy 500 1000 GeV

Design Luminosity 2 3 1034cm-2sec-1

Linac rf frequency GHzAccelerating gradient MV/mPulse repetition rate HzBunches/pulseBunch separation nsec

Particles/bunch x1010

Bunch train length msecBeam power 11 23 MW/beam

sx/sy at IP 655/7 554/4 nm

Site AC power 180 356 MW

5

1.3

2866

2820307

30


ILC Requirements and ChallengesEnergy: 500 GeV, upgradeable to 1000 GeV

• RF Accelerating Structures– Accelerating structures must support the desired gradient in an operational

setting and there must be a cost effective means of fabrication.

– ~17,000 accelerating cavities/500 GeV

– Current performance goal is 35 MV/m, (operating at 30 MV/m)

Trade-off cost and technical risk.

1 m

Risk

Cos

t

~T

heor

etic

al M

ax



Progress over the last several years has been in the area of surface processing (electro-polishing) and quality control.

Several single cell cavities at 40 MV/m (alternative shapes)

– European XFEL design goal of 28 MV/m ~1000 cavities fabricated over 2006-

2011

• Accelerating Structure Status– All high gradient 1.3 GHz accelerating cavities produced to date have been fabricated (by

European industry) and tested by the TESLA collaboration. Roughly 80-100 cavities >15,000 hours operation in the TESLA Test Facility (TTF) at DESY (Hamburg): two 8-

cavity cryomodules @ ~16 MV/m

– Five nine-cell cavities have tested successfully at >35 MV/m



• RF power generation and delivery– The rf generation and distribution system must be capable of

delivering the power required to sustain the design gradient: 10 MW 5 Hz 1.5 msec ~700 klystrons and modulators/500 GeV

– The rf distribution system is relatively simple, with each klystron powering 30-36 cavities.

• Status– Klystrons under development by three vendors (in Europe, Japan,

and U.S.) Three units from European vendor (Thales) have come close to

meeting spec. Sheet beam under development at SLAC (cost reduction)

– Modulators meeting performance spec have been built and operated (at TTF) for the last decade.


ILC Requirements and ChallengesLuminosity: 500 fb-1 in the first four years of operation

The specified beam densities must be produced within the injector system, preserved through the linac, and maintained in collision at the IR.

DCMyx

bD

yx

brep HEσπσ

NPH

σπσ

NnfL

44

2

Dy

b

CM

b

zxb H

E

PL

N

ss

2

2Note critical role

of y (b=3-5%)

– Sources 80% e- polarization ~1e+/e-; polarized?

– Damping Rings x/y = 8.0/.02 mm

– Emittance preservation Budget: 1.2 (horizontal), 2 (vertical)

– Maintaining beams in collision sx/sy = 540/6 nm


ILC Requirements and ChallengesLuminosity: 500 fb-1 in the first four years of operation

• The required emittances, x/y = 8.0/.02 mm, have been achieved in the Accelerator Test Facility (ATF) damping ring at KEK. However:

– Single bunch, e-

– Normalized, not geometric emittance– Circumference = 138 m (vs 6-17 km required for superconducting ILC)

• Emittance growth budget from DR to IR is 1.2 (H), 2.0 (V):– Growth: wakefields, alignment, and jitter

– Control is through “BNS damping” (wakes) and dynamic alignment control (alignment & jitter, ~300 mm, 300 mrad tolerances)

• Collisions:– Final Focus Test Beam (SLAC) achieved

required de-mag, but 10 beam size

– Intra-train feedback is required to maintain beams in collision


ILC Risk ElementsTechnical Performance/Energy

Energy = Gradient Length

• Cavity gradient– Will the operating gradient be sufficient to support the energy goal?– Potential mitigations

Establish realistically achievable gradient goal, based on modest extrapolation from current experience, consistent with fundamental limitations (~50 MV/m);

Design with operating margin relative to gradient goal; Install over capacity within the facility (~5%); Construct unfilled tunnel

• (Length—little risk the facility will come out shorter than designed!)

Assessment: Not the most serious risk. Risk reduction amendable to $$.


ILC Risk Elements Technical Performance/Luminosity

Luminosity= ∫L dt

• Peak Luminosity (L)– Significant extrapolation from experience base: ~104 SLC

Emittance capabilities of the source (esp. damping rings) Emittance preservation in the linac Maintaining nm beams in collision Detector backgrounds

– Potential Mitigations R&D on feedback, feedforward systems Integrated simulations

– Well characterized wakefields and alignment capabilities– Well characterized, quiet site

“Headroom”/alternative routes (parameter sets) to same luminosity

Assessment: Luminosity goals are very aggressive (driven by physics requirements) and represent significant risk.


ILC Risk Elements Technical Performance/(Integrated) Luminosity

Luminosity= ∫L dt

• Availability (∫dt)– Goal is 75% availability (actual/scheduled operations)

– Requires component mean time between failures (MTBF) typically a factor of 10 beyond current experience (~106-7 hours).

– Requires protection against beam “accidents” ~2 MJ per beam pulse (comparable to Tevatron, but smaller beam)

– Potential Mitigations: Operational modeling (complexity comparable to the Tevatron) Design up front for high MTBF Fail safe Machine Protection System Redundant systems/installed overhead

Assessment: Availability goals are aggressive for a facility of this complexity and represent significant risk.


ILC Risk Elements Cost Performance

• Can a reliable cost estimate be developed?– Significant experience base with components

representing ~50% of cost: Conventional facilities, cryogenics, magnets,

vacuum, controls systems

– Balance represents significant extrapolation: Accelerating structures, rf sources, systems

integration, beam delivery Savings for quantity production extrapolated

to lie in the range 3-5 for accelerating structures fabrication.

– Potential Mitigations: Well defined and controlled scope Complete systems testing, technology transfer, demonstrated industrial capabilities

and production models prior to construction start Multiple component streams Scope reduction strategies/scenarios identified up front

Assessment: Will have much better handle with CDR release.


ILC R&D ProgramStrategy

The purpose of the R&D program is to reduce risk. All risk elements need to be addressed in the pre-construction R&D program:

Technical, Cost, and Schedule performance.

• Strategy– Target critical performance and cost risk elements– Systems simulations based on characterizations from prototype components– Major demonstration projects to validate assumptions

• Program Elements– Preparation of a conceptual design (CDR), supported by subsystem R&D– Construction and testing of prototypes – Technology transfer and industrialization– Integrated systems testing – Development of plans for conventional facilities and infrastructure– Preparation of a final site-specific engineering design. – Preparation of regional hosting proposals

~Time


ILC R&D ProgramInternational/Regional Organization

ILC-Americas Regional Team Regional Director and Deputy Institutional ILC Managers for major instiutional members

CornellILC-NSF PI

TRIUMFILC-CanadaManager

NSF-funded Institutions

Canadian Institutions

Lead Labs

Work Package

Oversight ILCSC

GDE - Director

RegionalUSLCSG

FundingAgencies

FNALILC-FNALManager

WP 1.FNAL

WP 1.ANL

WP 3.FNAL

SLACILC-SLACManager

WP 2.SLAC

WP 2.BNL

WP 3.SLAC

communications

ILC-Asia ILC-Europe

International

Regional


ILC R&D ProgramAmerican Organization

Example North American ILC Matrix XX=Lead lab X=Participant

Institution Management Accelerator Cryomodules Cryomodule RF and Sources Damping Beam IR and MD Instruments ConvPhysics Cryogenics Test Facility Pulse Power Rings Delivery Interface & Controls Facilities

Fermilab XX XX XX XX X X X X X XX? XXSLAC XX XX X X XX XX X XX XX XX? XANL X X X XBNL X X XCornell XX X X X XXJeffLab X X XLBNL X XLLNL X X X XTRIUMF XX XUniversities X X X X X X

• Major initiatives & test facilities (US)– Significant presence within all major subsystems– Superconducting Module Fabrication and Testing Facilities

Industrialization (more advanced in Europe than US/Asia)

– Integrated systems test (linac)– Modeling/simulations– Site Development

• OverseasTTFIIEuroTevATFSTF


ILC R&D ProgramResource Requirements

• The USLCSG model shows (through site specific engineering design):– $650M (internationally shareable) costs

US share = $220M

– $300M of US bid-to-host and pre-construction activities (assumes success)– Total US expenditure ~$500M

• Accelerator scientist/engineer resources within this are estimated at:– ~400 person-years (total, American share)

– ~150 FTE (peak, American share)

• Currently available AS/E resources within the USHEP program:– ~70 FTE – currently working on ILC R&D

– ~140 FTE – currently engaged in accelerator operations (Tevatron, PEP-II, CESR); all scheduled to cease operations over 2008-2010.

Resources exist to execute the ILC R&D program without having to tap into other labs.

Dave: how much of this is

BTH and how much LLP?


ILC ConstructionResource Requirements

• The TESLA TDR estimated ~1400 person-years of accelerator scientist/engineers to construct.

– USLCTOS viewed this as a credible estimate.– ~250 FTE (peak, world-wide)– US share (if host) ~150 FTE– Well matched to the complement on hand at the end of the R&D program

Significant resources exist in non-HEP labs which could back this up subject to other programmatic goals (in US and abroad)

(~100 accelerator physics grad students in the DOE system at end of 2003).

Bottom line: The accelerator scientists and engineers needed to execute the ILC R&D and construction programs exist within the HEP program or are in the pipeline. Whether they will be available at the start of construction depends upon continuity of support.


Fermilab and the ILC Long Range Plan

• The Fermilab Long Range Plan establishes the ILC as the primary goal for Fermilab in the coming decades, with a world-leading neutrino program as the goal if the ILC were delayed or constructed elsewhere.

• The cold technology decision has allowed close alignment of Fermilab’s R&D programs in support of these goals.

Fermilab is pursuing ILC and “Proton Driver” R&D, in parallel, based on superconducting rf technologies.


Fermilab and the ILCFermilab as Host

• The FLRP advocates preparation of a Fermilab bid to host an international linear collider project and identifies attributes that we believe make Fermilab/northern Illinois very attractive as potential host:

– Fermilab Scientific and engineering expertise in forefront accelerator technologies Significant experience in construction and operations of large accelerator projects The leadership mantle of U.S. high energy physics

– Northern Illinois Strong scientific base, including two national laboratories and five major research

universities Geology ideally suited to a linear collider Transportation and utilities infrastructure system that could support LC

construction and operations.

DOE/SC has identified Fermilab/northern Illinois as the preferred U.S. site.

Am checking with Robin to

confirm he is onboard with this.


Fermilab and the ILCR&D Strategy

• Leadership of the America’s regional effort in development of the scrf technology base for the ILC.

– It is imperative to establish US-based capability in the fabrication of high gradient superconducting accelerating structures if the US is to compete to host.

Significant U.S. SCRF expertise at: Argonne, Cornell, Fermilab, Jefferson Lab, Los Alamos, Michigan State. Experience extends to both development and fabrication (e.g. SNS), but at gradients significantly below 35 MV/m (SNS cavity fabrication by European vendor).

– Fermilab is establishing facilities for the fabrication and testing of US-produced ILC superconducting modules with US and international partners.

Leveraging our significant infrastructure and scientific/engineering resources.


Fermilab and the ILCR&D Strategy

• Significant contributions to the understanding of beam dynamics issues:

– Low emittance transport through the linac

– Damping ring design

– Machine/detector interface issues

• (USLCSG) Bid to host– Site studies and

characterization– Public outreach

Fermilab is currently active in all these areas. The goal is to provide the US with the best possible host site for a prospective ILC bid.


Fermilab and the ILCCryomodule Fabrication and Testing Facilities

Fermilab has initiated work on two major facilities for ILC srf technology development:

Module Test Facility Cryomodule Fabrication Facility

SMTF Collaboration: ANL, BNL, Cornell, FNAL, JLab, LANL, LBNL, MIT, MSU, NIU, ORNL, Penn, SLAC, (CAT, DESY, INFN, KEK)


Fermilab and the ILCILC Proton Driver Synergies

• Motivation: Neutrino "superbeams"

• High level parameters:– 0.5-2.0 MW @ 8 GeV– 2.0 MW @ 120 GeV

• Possible implementations:– 8 GeV synchrotron; or– 8 GeV superconducting linac

• The superconducting linac is preferred: – Synergy with ILC R&D

cavity development, industrialization, systems testing– Lower beam emittance– Better performance over entire energy range– Flexibility for the future


Fermilab and the ILCILC Proton Driver Synergies

R F QR F Q

Modulator

H -

B=0.47 B=0.47 B=0.61 B=0.61 B=0.61 B=0.81 B=0.81 B=0.81 B=0.81 B=0.81 B=0.81 B=0.81

Modulator

"Pulsed RIA" SCRF Linac 325 MHz 0 - 120 MeV

B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1

Modulator Modulator

12 Klystrons (2 types) 11 Modulators 20 MW ea. 1 Warm Linac Load 54 Cryomodules~550 Superconducting Cavities

8 GeV 0.5 MW LINAC

8 Klystrons288 cavites in 36 Cryomodules

2 Klystrons96 cavites in 12 Cryomodules


Modulator Modulator


Modulator Modulator


Modulator Modulator

Modulator

48 cavites/ Klystron

36 cavites/ Klystron

TESLA Klystrons1300 MHz 10 MW

"Squeezed TESLA" Superconducting Linac1300 MHz 0.087 - 1.2 GeV

"TESLA" LINAC 1300 MHz Beta=1

S S RS S RS S RD S RD S RD S R

Multi-Cavity Fanout at 10-20kW/cavityPhase & Amplitude Adjust via Fast Ferrite Tuners

TESLA Klystrons1300 MHz 10 MW

325 MHz Klystrons1.5 MW

“ILC” LINAC

Considerable technology overlap with ILC:

– ILC compatible frequencies

– Structure development and industrialization


Fermilab and the ILCTimeline/decision tree

• Between now until 12/31/06 Fermilab R&D activities are independent of the final destination:– Completion of ILC CDR with supporting R&D

– Completion of PD CDR with supporting R&D

• A series of branch points then develops in response to the ILC CDR, leading over the balance of the decade to either:– A decision to construct ILC (soon); or

– A decision to construct the Proton Driver; or

– …

See Pier Oddone’s presentation for details.


Summary

• The ILC represents an enterprise at the forefront of both human knowledge and human technical capabilities.

– A undertaking worthy of the United States!

• ILC performance goals have been established.– Based on >10 years of R&D in U.S., Europe, and Japan

• ILC risk elements have been identified and motivate an R&D program supporting a complete engineering design by the end of the decade.

– Luminosity goals are more challenging than energy.– CDR will establish an initial cost range at the end of 2006.

• The US R&D program is being reoriented in response to the technology decision and in alignment with the international framework.

• Fermilab’s R&D program is aligned with US aspirations for the future– SCRF R&D is the unifying technology theme

• Fermilab is committed to a leadership role in the ILC R&D program and to preparing itself to host the ILC if/when that decision comes.


References

International Linear Collider Steering Committeehttp://www.fnal.gov/directorate/icfa/International_ILCSC.html

U.S. Linear Collider Steering Grouphttp://www.slac.stanford.edu/~hll/USLCSG/

Machine performance specificationhttp://www.fnal.gov/directorate/icfa/LC_parameters.pdf

TESLA TDRhttp://tesla.desy.de/new_pages/TDR_CD/start.html

(USLCSG) U.S. Linear Collider Technology Options Studyhttp://www.slac.stanford.edu/xorg/accelops/OptionsReport/LC_opts_full.pdf

Technical Review Committee

http://www.slac.stanford.edu/xorg/ilc-trc/2002/index.html

Fermilab Long Range Planhttp://www.fnal.gov/directorate/Longrange/Long_range_planning.html

Fermilab ILChttp://ilc.fnal.gov/index.html

Fermilab Proton Driverhttp://www-bd.fnal.gov/pdriver/

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The International Linear Collider Accelerator R&D Program

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