SLAC Accelerator Program Overview

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SLAC Accelerator Program Overview

• D. L. Burke
• NLC Program Director

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Accelerator Facilities at SLAC
ASSET
FFTB
PEP-II
BABAR
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The SLAC Science Program
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The Research Yard - Looking West
Nobel Prize for discovery of constituents in the
proton (Friedman, Kendall, and Taylor).
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SPEAR
Thirty years of science and innovation.

• Built in 1972 as e/e- collider.
• Nobel Prizes for discoveries of
• J/? (Richter) and t (Perl).
• Dedicated light source in 1989.
• 2003 SPEAR3 Third-Generation.
• Completely rebuilt lattice and rf.
• Low emittance optics.
• I 500 (100) mA.
• 11 beamlines.

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SPEAR3 Commissioning Milestones

• 2003
• 1 April SPEAR2 removal begins
• 9 December Transport line commissioning
• 10 December First beam to SPEAR
• 15 December First accumulation
• 2004
• 22 January 100 mA stored
• 8 March First photons
• 15 March Start operations

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Commissioned rapidly and experimental program now
underway.
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Linac Coherent Light Source (LCLS)
1992 Proposal (C. Pellegrini) 1998 Preliminary
Design Study Completed 1999 RD funded at
1.5M/year 2002 Conceptual Design
Completed. 2003 Project Engineering Design
Began 2005 Long-Lead Procurements Begin 2006
Construction begins 2007 First Light 2008
Project completion
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Self-Amplified Spontaneous Emission (SASE)
An electron bunch in an undulator can emit
synchrotron radiation that modifies the electron
bunch itself. The electron beam begins to form
micro-bunches, .
The micro-bunches radiate coherently to produce
intense short-pulse coherent light.
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The PEP-II Asymmetric ee- Collider
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Run 4
Run 3
Run 2
Run 1
Design Performance
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Future PEP-II Luminosity Increases
Parameter Present Future Luminosity gain Hardware and Work
LER current 2250 mA 4500 mA Two RF stations, new vacuum chambers.
HER current 1380 mA 2200 mA 1.78 Two RF stations, new vacuum chambers.
by 11 mm 8 mm 1.38 HER higher tunes, RF power supplies improvements.
xy 0.068 L 0.045 H 0.079 L 0.053 H 1.16 Tune plane, coupling, IR work.
Parasitic Dx 3.22 mm 3.80 mm 1.06 New IP B1 magnet.
Total 3.00
Goal for 1996
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Advanced Accelerator Research at SLAC

• Laser-Driven Accelerator Structures
• Rapidly advancing field of photonics.
• Concepts for accelerator structures, wakefields,
  and efficiency.
• Experiment (E166) installed at the NLCTA.

• Plasma Wakefield Acceleration
• Electron positron transport and acceleration
  in a long plasma.
• Accelerating gradients greater than 15 GeV/m
  sustained over 10 cm in experiments in the FFTB.

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SLAC PhDs in Accelerator Physics

• SLAC students have won 5 out of the 6 APS
  Outstanding Theses Awards on Beam Physics
• 1999 Zhirong Huang
• Radiative Cooling of Relativistic
  Electron Beams
• 2001 Shyam Prabhakar
• New Diagnostics and Cures for Coupled
  Bunch Instabilities
• 2002 Boris Podobedov
• Saw Tooth Instability Studies at the
  Stanford Linear Collider Damping Rings
• 2003 David Pritzkau
• Rf Pulsed Heating
• 2004 Dmitry Teytelman
• Architectures and Algorithms for Control
  and Diagnostics of Coupled Bunch Instabilities
  in Circular Accelerators

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The Stanford Linear Collider (SLC)
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The First Linear Collider the SLC
New Territory in Accelerator Design and Operation
On-line real-time instrumentation, data analysis,
and control. Automated second-order tuning and
control of precision beams. ? Lessons built
into design and technology of a TeV linear
collider.
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Future TeV Linear Collider
Two Teams One Choice Extension of conventional
warm accelerator technology from 3 GHz
(S-Band) to 11.4 GHz (X-Band).
NLC
JLC
SLAC-KEK RD MOU signed in 1998.
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X-Band 250 GeV Linacs with TeV Technology and
Tunnel Length for 500 GeV/Beam
Evolution of a common design strategy NLC
Zero-Order Design JLC Design Study (1996) NLC
DOE Lehman Review (1999) NLC Snowmass
2001 (2001) GLC Project Report (2003) GLC/NLC
TRC (2003)

Two IRs
32 km
3.5 km

Bypass Lines e.g. 50, 175, 250 GeV

Injector Systems for 1.5 TeV
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ATF Damping Ring at KEK
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• Final Focus Test Beam
• Collaboration
• BINP (Novosibirsk)
• DESY
• Fermilab
• IBM
• Kawasaki
• KEK
• LAL (Orsay)
• MPI(Munich)
• Rochester
• SLAC

1997
1997
Vertical beam size of 60-70 nm the needed
demagnification.
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The Test Accelerator at SLAC
The NLCTA with 1.8 m accelerator structures
(1997).
First-generation X-band accelerator with 40 MV/m
gradient.
Demonstrated ability to reach 500 GeV cms.
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X-Band 1 TeV Baseline RF Unit
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GLC/NLC Level I RD Requirements (R1)

• Demonstration of SLED-II pulse compression
  system at design power level.
• Test of complete accelerator structure at design
  gradient (65 MV/m) with detuning and damping,
  including study of breakdown and dark current.

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Solid-State Modulator and Dual-Mode SLED-II
TRC R1 Done. Power 580 MW to loads (design is
475 MW) at 400 ns. Operated over 1500 hours.
Turn-key with feedbacks.
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X-band Structure Operations at NLCTA
Structure Manufacturer Gradient (MV/m) Trip Rate (/hr)
H60vg4S17-FXD1A FNAL 65.4 0.044
H60vg3S17-FXC5 FNAL 64.4 0.025
H60vg4S17-3 KEK/SLAC 65.4 0.050
H60vg3S17-FXC3 FNAL 64.4 0.031
H60vg3-FXB6 FNAL 65.1 0.013
H60vg3-FXB7 FNAL 67.0 0.132
H60vg4S17-1 KEK/SLAC 63.5 0.060
H60vg3R17 SLAC 65.1 0.076

Average (23-July-04) Average (23-July-04) 65.0 0.054
Average One Month Earlier Average One Month Earlier 64.9 0.085
Average Two Months Earlier Average Two Months Earlier 64.9 0.163
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Ready to Initiate International Linear Collider
Project

• Baseline technologies and design are proven.
• Major improvements will come from value
  engineering and industrial design for
  manufacture, reliability, and serviceability.
• Industrial technologies readily and widely
  available.
• RD will continue to look for ways to improve on
  the baseline e.g., better power efficiency with
  DLDS.

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Project Initiation The First YearsInternational
ly Sharable Activities

• Engineering and Design
• Accelerator Physics
• Value Engineering and Design Reliability,
  Serviceability, Cost
• Aspects of Site and Civil Engineering and Design
• Risk Analysis, Project Planning, and CDR/TDR
• RD
• Continued Technology Development
• Instrumentation, controls, and software
• Specialized components e.g., collimators,
  kickers, etc.
• Options beyond the Baseline
• Support for Industrialization
• Prototyping
• QC and Testing

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The Global Design Initiative

• The International Linear Collider Steering
  Committee (instituted by ICFA) will select
  between competing collider technologies, and
  start a Global Design Initiative for an
  International Linear Collider.
• International Technical Recommendation Panel
  (ITRP)
• NLC and GLC Collaborations make strong, coherent,
  and well coordinated presentations of the X-Band
  technology.
• Recommendation on X-Band or Superconducting
  technologies expected this year (likely at the
  meeting of ICFA in Beijing on August 20).
• Global Design Initiative Goals
• 2005-2006 Phase I Global Conceptual Design
• 2007-2008 Phase II Engineered Technical Design
• 2009 Site Selection and Construction Organization

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Government Agency Discussions

• The U.S. Department of Energy long-range roadmap
  of science facilities needed to maintain
  excellence in science
• TeV linear collider is the first priority
  mid-term facility.
• Leaders of funding agencies of Canada, France,
  Germany, Italy, Japan, United Kingdom, United
  States, and representatives of the CERN Council
  have met three times in London to discuss the
  ILC.
• These Agencies look forward to the ITRP
  technology selection and recognize and support
  the Global Design Initiative.
• Targets for completion of the RD and design,
  and final organization and approval of
  construction with the goal to begin physics
  studies in the middle of the next decade
• 2009 Site Selection and Construction
  Organization
• 2010 Final Go Ahead and Construction Start
• ? 2015 Collisions and Commissioning

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SLAC and Global Collaboration

• SLAC will be a strong collaborator in the ILC
  regardless of the technology selection for the
  main accelerator.
• The expertise and experience of SLAC personnel
  will support the completion and implementation of
  the best possible design for the collider.
• The accelerator facilities and beams at SLAC
  will be important in the continuing program of
  RD.
• SLAC has long fostered and enjoyed international
  collaboration on the development of the linear
  collider, and the people of SLAC are excited to
  continue to work with the global community of
  scientists and engineers to make a TeV collider a
  reality.