# Presentation: 178177

## ILC Workshop at Snowmass

- WG5: Superconducting Cavities and Couplers, Helen Edwards
- WG1: Low Emittance Transport & Beam Dynamics and WG2: Linac Design, Shekhar Mishra
- WG3a: Source, Philippe Piot
- WG4: Beam Delivery, Nikolay Mokhov
- GG5: Cost and Engineering, Bob Kephart
- GG4: Civil and Siting, Vic Kuchler
- WG6: Communication and Outreach, Judy Jackson
- WG3: Damping Ring, Shekhar Mishra
- Overall Plan for the Workshop and Fermilab, Shekhar Mishra

## Snowmass Working Groups

- WG1: LET Beam Dynamics: K. Kubo, D. Schulte, P. Tenenbaum
- WG2: Linac Design: H. Hayano, T. Garvey, C. Adolphsen
- WG3a: Sources: M. Kuriki, J. Clarke, J. Sheppard, P. Piot
- WG3b: Damping Rings: J. Gao, S. Guidicci, A. Wolski
- WG4: Beam Delivery: T. Sanuki, G. Blair, A. Seryi
- WG5: Superconducitng Cavities & Couplers: K. Saito, D. Proch, H. Edwards
- WG6: J. Jackson, N. Calder, Y. Morita, K. Buesser

## ILC Global Groups

- GG1: Parameters: K. Yokoya, N. Walker, T. Raubenheimer
- GG2: Instrumentation & Controls: J. Urakawa , H. Braun, M. Ross
- GG3: Operations & Availability: TBD,  E. Elsen, T. Himel
- GG4: Civil & Siting: A. Enomoto, J-L. Baldy, V. Kuchler
- GG5: Cost & Engineering: T. Shidara, W. Bialowons, R. Kephart
- GG6: Options: Omori, V. Telnov , B. Parker

## Schedule of the Workshop

## Low Emittance Transport and Beam Dynamics

- Nikolay Solyak
- Kirti Ranjan
- Paul Lebrun
- Panagiotis Spentzouris
- Lynn Garren
- Mike Church
- Sergei Nagaitsev

## LET Layout:
Can we use a configuration other than laser-straight (curved, bent)?
What are the drawbacks to such configurations?
What are the longitudinal options in layout, and which option is best?
Bunch Compressor:
What are the tradeoffs in selecting single vs multi-stage bunch compressors? 

- Can we use a configuration other than laser-straight (curved, bent)?
- What are the drawbacks to such configurations?
- What are the longitudinal options in layout, and which option is best?
- Bunch Compressor:
- What are the tradeoffs in selecting single vs multi-stage bunch compressors?

## RF Stability

- What is the state of the art in achieved RF phase and amplitude stability,  and how does it compare with the demands made by luminosity production in the ILC?
- Cryomodule Vibration Source
- What is the expected / achievable minimum amount of vibration due to in-cryomodule sources which can be achieved, in particular for the main linac quads?
- Integrated Simulations
- What is the current state of simulations which are integrated over the full LET? What additional work must be done to confidently estimate the luminosity performance of the ILC?
- What is the likely luminosity performance of the ILC?

## Main Linac Dynamics

- How reliable are estimates of the intensity of the short-range wakefields?
- How severe do we expect the emittance dilution from multi-bunch wakes
- to be (esp. considering the possible rogue mode and mode-rotation issues)?
- How effective are the emittance tuning procedures under consideration for the main linac?

## Modulators

- Status of baseline modulators at DESY
- Upgrades to the FNAL modulators for SMTF
- Development of a Marx modulator at SLAC, and thru SBIR’s
- Development and operational experience with Direct Switch modulators (DTI)
- Other modulator possibilities
- Experience with the SNS HVCM’s
- Design for high availability
- HV power transport (at 10 kV or 120 kV)
- Magnetic fields generated by modulators or transformers in the beamline tunnel
- Cost comparison of baseline and alternative designs

- SLAC
- Ray Larsen
- Greg Leyh
- Dick Cassel
- FNAL
- Howard Peffer
- Chris Jensen
- DESY
- Stefan Choroba
- PAL
- Jong-Seok Oh

## Klystrons

- Test results from DESY on Thales, CPI and Toshiba 10 MW tubes
- Layout issues and development of horizontal tubes
- Industrialization for XFEL and ILC
- Long term testing facilities and plans
- Sheet beam alternative and cost comparison
- Other rf source schemes
- Low power, local sources
- High power, combined klystron

- SLAC
- George  Caryotakis
- Daryl Sprehn
- Sami Tantawi
- FNAL
- Al Moretti
- John Reid
- DESY
- Stefan Choroba
- KEK
- Sergey Kazakov

## Low Level RF

- Performance of LLRF system at TTF in comparison with ILC requirements
- Requirements and plans for XFEL
- Implication of different tunnel scenarios
- SNS design and experience
- Plans for SMTF and STF

- SLAC
- Steve Smith
- Marc Ross
- Josef Frisch
- FNAL
- Brian Chase
- Ralph Pasquinelli
- Ruben Carcagno
- DESY
- Stefan Simrock
- JLAB
- Jean Delayen

## RF Distribution

- Cost-optimized configuration and development of industrial vendors
- Waveguide power losses and cooling – implications for the tunnel layout
- Breakdown limits in waveguides and circulators
- Waveguide pressurization – alternatives to SF6
- Alternative distribution schemes
- Elimination of circulators

- SLAC
- Sami Tantawi
- Christopher Nantista
- KEK
- Sergey Kazakov
- FNAL
- Ralph Pasquinelli
- DESY
- Stefan Choroba
- LLNL
- Brian Rusnak

## Couplers (with WG5)

- Progress in processing TTF3 couplers at Orsay
- Status of new designs
- Plans for characterizing coupler performance for 35 MV/m operation
- Modeling of coupler multipacting
- Proposed tests to understand the coupler processing limits
- Coupler plans for the XFEL
- ILC industrialization and cost issues

- FNAL
- Nikolay Solyak
- KEK
- Hiroshi Matsumoto
- Sergey Kazakov
- Shuichi Noguchi
- Eiji Kako
- LLNL
- Brian Rusnak
- Orsay
- Terry Garvey
- Alessandro Variola

## Cryomodules (with WG5)

- Status of TTF cryomodules
- Design changes for XFEL-cryomodules
- Design changes for the ILC
- Schedule for TTF/XFEL/SMTF prototypes
- Industrialization of the XFEL cryomodules
- Identification of critical requirements
- Existing and planned cryomodule infrastructures
- Cryomodule integration issues
- Separate Quad / Cavity sections
- Adoption of international standards

- FNAL
- Harry Carter, Tug Arkan, Cristian Baffo, Don Mitchell, Nikolay Solyak, Andrew Hocker, Helen Edwards
- JLAB
- Warren Funk, Peter Kneisel, Jean Delayen
- DESY
- Lutz Lilje, Carlo Pagani, Dieter Proch, Detlef Reschke, Bernd Petersen
- KEK
- Shuichi Noguchi, Kenji Saito, Fumio Furuta, Yuichi Morozumi, Toshiyasu Higo, Eiji Kako, Norihito Ohuchi

## Test Facilities (with WG5)

- Experience at TTF
- Possible experiments at TTF
- Plans at FNAL, SLAC, JLAB and KEK
- Resource sharing

- SLAC
- Chris Adolphsen
- FNAL
- Shekhar Mishra
- Peter Limon
- JLAB
- Swapan Chattopadhyay
- DESY
- Hans Weise
- KEK
- Hitoshi Hayano
- U of Pennsylvania
- Nigel Lockyer

## Cryogenic System / AC Power / Cooling(with G4)

- Update of the TDR design based on new technology and new cost info
- Implications for the various tunnel layout schemes
- Reliability issues

- FNAL
- J. Theilacker
- A. Klebaner
- Tom Peterson
- Paul Czarapata
- SLAC
- Fred Asiri
- Clay Corvin
- DESY
- Heiko Ehrlichmann
- Franz Peters
- Wilhelm Bialowons

## Linac Beam Dynamics (with WG1)

- Beam-based quad alignment implications
- Linac straightness and terrain following limitations
- Quad design and aperture limits
- Dipole mode polarization affect on beam orbit coupling
- BPM requirements
- Cavity tilts and beam centering
- Vibration and stray magnetic field limits
- Diagnostic regions
- Tests of quad shunting and linac bpm performance

- SLAC
- Peter Tenenbaum
- Gennady Stupakov
- Yuri Nosochkov
- Roger Jones
- Gerald Yocky
- FNAL
- Nikolay Solyak
- Kirti Ranjan
- Paul Lebrun
- Panagiotis Spentzouris
- DESY
- Nicholas Walker
- KEK
- Kiyoshi Kubo
- Other
- Daniel Schulte (CERN)
- Francois Le Diberder (CNRS)
- John Cary (U of Colorado )

## Cavity Wakefields

- 3D cavity simulations for baseline and low loss designs
- Equivalent circuit modeling of 4-8 GHz modes
- Status of wakefield measurements at DESY
- Development of high frequency absorbers

- SLAC
- Zenghai Li
- Juwen  Wang
- Liling Xiao
- Roger Jones
- DESY
- Jacek Sekutowicz
- FNAL
- Nikolay Solyak
- KEK
- Yuichi Morozumi
- Eiji Kako

## Other Linac/RF topics

- Positron Capture Cavities
- Crab Cavities
- Polarized RF Gun
- RF BPMs
- 3.9 GHz Compressor Cavities

- SLAC
- Steve Smith
- Marc Ross
- Juwen  Wang
- Frans Josef Decker
- Josef Frisch
- FNAL
- Nikolay Solyak
- DESY
- Klaus Floettmann
- Other
- Wei Gai (ANL)
- A. Mikhailichenko (Cornell)
- Naoto Yamamoto (Nagoya)

## Baseline Configuration Document 

- Tunnel Layout
- Cut and Cover
- TDR like
- Deep (> 20m) Tunnels
- Modulators
- Pulse Transformer
- Marx Generator
- Other
- Klystron
- Multibeam tube
- Sheet beam tube
- Other
- RF Distribution
- TDR like
- Other configurations

- At Snowmass, outline linac choices, giving pro’s and con’s for various items or specifying those to which there is general agreement

- Quad and BPM package
- Integrated at center
- Integrated at end
- Separate
- Quad
- Cos(2Phi) 80 mm bore
- Superferric 40 mm bore
- BPM
- Narrow band cavity
- Wide band
- Cryo Cooling Issues
- Segmentation
- Shield temperatures
- Overhead
- Other
- Modulator/Klystron Cooling
- Tunnel Electronics

- Coupler
- TTF3
- Higher power variation
- Waveguide like
- Cavity Design
- TDR
- Low Loss
- Cavity Gradient
- 25, 30, 35 MV/m
- Dark current limits
- Cavity Tuners
- End
- Blade
- Other
- Cavities per Cryomodule
- 8 or 12

## Damping Ring: WG3B

- Acceptance
- Space-Charge
- Emittance Tuning
- Instabilities
- Kicker and Instrumentation
- Electron Cloud
- Ion-Effects
- Beam Losses, Polarization, Predamping Ring
- Test Facilities and Experimental Program
- Cost Estimate