Draft WG5 Cavities Topics ( with overlap with WG2)

1. Draft WG5 Cavities Topics ( with overlap with WG2) • General Cavity parameters (R&D goal & LC operating goal) • Cavity type • * Hi Gradient R&D • * Materials R&D • * Input coupler • * Tuners (fast & slow) • * Fabrication • Processing (including.EP, HT…) • Cryo Module & String Assembly • * Industrialization Those noted by “*” are listed topics for WG5 from organizers and will be denoted by * also in what follows

2. Work plan • Before Snowmass • Preliminary Strawman choice for “ Baseline Configuration Design” (BCD) • And alternative(s) for Alternate Configuration Design (ACD) • Previous WSs have considered TESLA as starting strawman • Baseline NEED NOT be present existence proof (TESLA) • But one should show clear justification & path between evolution from Tesla BCD(s) ACDs (with priorities)

3. Work Plan continued • Enumerate justification of baseline and alternatives • Pros and cons of choices, technical advantages/ disadvantages • Potential Mods or improvements to choices • Technical advantages, Increased technical potential • Potential cost reductions • Risk and reliability impacts • R&D necessary and time scale • Of the baseline • Of alternatives to supersede baseline status.

4. Proposed methodology • We propose to put forward a set of “preliminary” reference design parameter choices and prioritized alternatives prior to the meeting. • In the discussion/ presentation sessions we will ask for people who do not believe a particular reference selection correct, that they present arguments for alternative to the selected choice. • Improvements to and needed design reviews of the choice would follow • This discussion would be followed by discussions of alternative options and their priority, and importance. Leading to an R&D plan • For instance -

5. Steps for design convergence and R&D plan • Put out a draft of tentative parameter items choices Prior to Snowmass • Encourage people to make arguments that other alternatives are better for “base line” choice • Change selection if appears justified-consensus • make lists of pros & cons • Discuss work to be done or to be reviewed on the primary choice (its R&D) • Discuss and prioritize other options • Outline their needed R&D • Identify potential cost reduction, technical risk, technical advantages, increased potential

6. Schedule at Snowmass • Agenda WG 5 Week one Aug 15- 19 • Tues Day 2 Time available 120, 120min, 90 minGG • (WG 2- Mod, Kly, llrf, RF dist) • WG 5- (This may be too much on this day) • Review of strawman for BCD, • Gradient and Q0 R&D goals & LC spec, • Cavities, geometries • Fab, Processing & • Industrialization • Resources for cavity test

7. Wed Day 3 Time alloted 120, 120 min, GG90min • WG 2&5 – Cryo module, Couplers.., Cryo temp opt • WG 2 & 5? with GG3 (availability- Cryo systems, tunnel layout, modulators) • WG5 and 2? with GG1? on gradient issues, and packing factor/ slot length? • Thurs Day 4 Time alloted 120, 120 min, GG90min • WG 5 • Morning- • Materials R&D – and basic research towards BCD and ACD • tuners (including step motors), and mag shielding • Afternoon • Draft Conclusions - some with WG2? • WG5 with GG availability, tuners, ?? …

8. Criteria • Baseline recommendation (BCD) • Need not be an existing design, but should be either • A mature design or procedure • A modification easy to extrapolate to without significant R&D program • A design or procedure, though not completely certified, likely to be the one of choice • One for which costing with contingencies is possible or available • One with such significant benefit over existing concept to warrant its choice • Should have a clearly defined R&D path to bring to credible stage

9. Criteria cont1 • Primary Alternative to baseline (ADC) • Design or concept warranting aggressive R&D effort. • Likely to overtake baseline if pursued • Likely to have significant technical or cost advantages • Define R&D required to bring to credible stage

10. WG5 Cavities Topics • General parameters & concepts • Gradient & Q • Goal for cavity R&D • Specification for ILC 500 • Reserve • Reliability & Risk • Cost- benefit • Linac packing factor • Cavity types • Needs evaluations of all aspects. • TESLA -Mods to TESLA? • Beam pipe length & diameter • HOM and pickups • Helium vessel & Conical end • End group cooling, end group design • Flanges and Sealings • General design cleanup

11. WG5 topics cont 1 • Cavity types continued • Low loss - impact of smaller iris?,cell to cell coupling, beam dynamics , alignment tolerances • Reentrant- or hybrid reentrant - cleaning & structural • Other variants • Superstructure • *Hi Gradient R&D • Processing • BCP w Ti & 1200C, EP, mechanical grinding, 120 bake • BCP w single crystal, or large grain • Understand process parameters to reduce spreads • Discuss paths toward industrialization • Processing toward industrialization (see industrialization) • Margin & qualification specifications • What gradient margin, Q margin • What dark current and x-rays • Risks - vacuum accidents

12. WG5 topics cont 2 • *Materials R&D • Do we need 1300 C Ti treatment? • Single & large grain • Connection w processing • Nb/Cu • Basic reaserch • Q improvements • *Fabrication • E beam • Hydroform • Spin • Tolerances • End groups - can one improve fab efficiency? • *Industrialization • Key issues toward • A plan and schedule • Quality control & reproducibility

13. WG5 topics cont 3 • Tuners • Types mechanical • End type Saclay • Blade type • Coaxial • Other • Piezo (range for highest gradient?) • Magnetostrictive • Motors- warm vs cold • Magnetic shielding

14. WG5 with WG2 topics cont 4 • *Input couplers • Varieties • New ideas • Processing • Cost drivers • R&D for cost or processing • CryoModule • The string: bellows, GVs, HOM abs, BPM/Quad • The quad/BPM location • Cavity slot length • Cavity & module Interconnect and their real estate • Generic module types • With quad/ without q/ separate quad module

15. DESY Dieter Proch Lutz Lilje W-D Moeller R Brinkmann Detlef Reschke J Sekutowicz KEK-Japan Kenji Saito Toshiyasu Higo Yasuo Higashi Eiji Kako Shuichi Noguchi Hiroshi Matsumoto Sergey Kazakov Kenji Ueno JLab Peter Kneisel Rao Myneni Charles Reece Jean Delayen Warren Funk John Mammosser Joe Preble Cavities WG5 key people This is just a first attempt at trying to identify people from the overall list. As I don’t know people at some Labs well there may be gross oversights Or errors

16. FNAL Pierre Bauer Harry Carter H Edwards Mike Foley Don Mitchell Nikolay Solyak SLAC Chris Adolphsen J Cornuelle Saclay/Orsay Terry Garvey O Napoly Cornell Hasan Padamsee (2nd week) Mathias Liepe Rongli Geng INFN Carlo Pagani Industry Michael Peiniger Tony Favale Tony Nelson? Other John Corlett Brian Rusnak Cavities WG5 key people cont 1

17. 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 Don Mitchell KEK Hiroshi Matsumoto Sergey Kazakov Shuichi Noguchi Eiji Kako Cornell Sergey Belomestnykh LLNL Brian Rusnak Orsay Terry Garvey Alessandro Variola DESY W-D Moeller Couplers (with WG5)Chris Adolphsen transp

18. 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 Tom Peterson (or Tom Nicol) ? JLAB Warren Funk, Peter Kneisel, Jean Delayen, Reece, Preble Cornell M. Liepe DESY Lutz Lilje, Carlo Pagani, Dieter Proch, Detlef Reschke, B. Peterson KEK Shuichi Noguchi, Kenji Saito, Fumio Furuta, Yuichi Morozumi, Toshiyasu Higo, Eiji Kako, Norihito Ohuchi Cryomodules (with WG5)Chris Adolphsen transp

19. Baseline Configuration Document Chris Adolphsen transp At Snowmass, outline linac choices, giving pro’s and con’s for various items or specifying those to which there is general agreement • Tunnel Layout • Cut and Cover • TDR like • Deep (> 20m) Tunnels • Modulators • Pulse Transformer • Marx Generator • Other • Klystron • Power Level • Multibeam tube • Sheet beam tube • Other • RF Distribution • TDR like • Other configurations • 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 to 12