1. Nick Walker – GDE meeting Frascati 8.12.05 Discussion and Approval of the BCD Nick Walker ILC-GDE Frascati – 8.12.2005

2. Nick Walker – GDE meeting Frascati 8.12.05 The Next Two Hours The road to the BCD  brief recap of the process since Snowmass Review of the White Papers BCD EC decisions for the strawman BCD  what changes we made Review of comments and feedback  some comments we have received  what’s missing from the BCD Formal acceptance of the BCD

3. Nick Walker – GDE meeting Frascati 8.12.05 Arriving at the BCD 1 st ILC Workshop at KEK (11.2004)  working groups (WG) formed to begin identifying contentious design issues 2 nd ILC Workshop Snowmass (8.2005)  modified WG continue identifying baseline design and alternatives  newly formed ‘Global Groups’ begin to discuss and catalogue global design issues  2 nd Snowmass week: concentrate on the list of ‘Top 40’ critical design questions (Himel List)

4. Nick Walker – GDE meeting Frascati 8.12.05 Arriving at the BCD (cont) Comments on Snowmass  first week: formal workshop with traditional parallel working groups  second-week: entire ILC community not present, but those that remain make significant progress on identifying baseline. It was understood that the result of 2 nd week deliberations did not necessarily reflect the consensus view of the entire community.

5. Nick Walker – GDE meeting Frascati 8.12.05 Arriving at the BCD (cont) August SeptemberOctober November December 2005 WW/GG summaries + broader input Response to Himel list (40 questions) all documented ‘recommendations’ publicly available on www (request community feedback) review by BCD EC BCD EC publishes ‘strawman’ BCD public review Frascati GDE meeting BCD Executive Committee (EC): Barish Dugan, Foster, Takasaki (regional directors) Raubenheimer, Yokoya, Walker (acc. design leads)

6. Nick Walker – GDE meeting Frascati 8.12.05 Arriving at the BCD (cont) August SeptemberOctober November December 2005 WW/GG summaries + broader input Response to Himel list (40 questions) all documented ‘recommendations’ publicly available on www (request community feedback) review by BCD EC BCD EC publishes ‘strawman’ BCD public review Frascati GDE meeting Request for public comment and feedback

7. Nick Walker – GDE meeting Frascati 8.12.05 BCD EC review process Snowmass documentation comments and feedback from general community ‘white-paper’ task groups on identified contentious items Barish ‘mini-MAC’  Burt Richter (SLAC)  Katsunobu Oide (KEK)  Lenni Rivkin (PSI)

8. Nick Walker – GDE meeting Frascati 8.12.05 White Papers Energy upgrade  Lijle, Raubenheimer, Toge IP configuration  Bialowons, Markiewicz, Yamamoto Number of tunnels  Delahaye, Hayano, Phinney Location of positron source  Himel, Walker, Yokoya Tunnel topology  Funk, Schulte, Shidara

9. Nick Walker – GDE meeting Frascati 8.12.05 BCD EC contrary decisions Energy upgrade – short tunnel adopted  option 3 in white paper Main linac quadrupole spacing  32 quads per quadrupole (24 recommended by WG1) RTML (bunch compressor)  cost minimal system (two-stage compressor)  evaluate (cost) single-stage system with two-stage system as upgrade rationale: cost

10. Nick Walker – GDE meeting Frascati 8.12.05 Comment and feedback SLAC ILC group  modulator baseline  e+ source location (→ white paper) Armin Reichold (Oxford)  no BCD entry for survey & alignment Weiren Chou (FNAL)  question concerning gradient cost optimum GG2 conveners (Braun, Ross, Urakawa)  recommendation for ~1  m linac BPM resolution (current BCD is ‘less than 10  m’) Gudrid Moorgat-Pick  Importance of focus on CME ≤ 500GeV (strong physics case)  Concerns on potential  1TeV upgrade driving initial design

11. Nick Walker – GDE meeting Frascati 8.12.05 Barish ‘Mini-MAC’ high-points Richter  importance of energy flexibility and incremental energy upgrade physics-driven in light of early LHC results  The case for 2 detectors – 2 IRs Oide  luminosity parameters – designing a 5×10 34 machine  Design of RF system to ‘true average gradient performance’  Questions concerning e+ source  DR discussions (favours dogbone?) BCD EC will respond to all comments and questions

12. Nick Walker – GDE meeting Frascati 8.12.05 The Baseline Machine (500GeV)

13. Nick Walker – GDE meeting Frascati 8.12.05 1TeV upgrade

14. Nick Walker – GDE meeting Frascati 8.12.05 The Baseline Machine (500GeV) not to scale ~30 km e+ undulator @ 150 GeV (~1.2km) x2 R = 955m E = 5 GeV RTML ~1.6km ML ~10km (G = 31.5MV/m) 20mr 2mr BDS 5km

15. Nick Walker – GDE meeting Frascati 8.12.05 BCD Current baseline rather superficial in many places  exception: main linac technology Many inconsistencies  need pedantic review of details Much detail still missing and needs to be supplied  tables of parameters  tables of tolerance  figures (cartoons) of basic layouts  lattices  … First work for AGs over the next couple of months (together with the CCB)

16. Nick Walker – GDE meeting Frascati 8.12.05 Formal Acceptance of BCD You got a problem with that? BCD EC

17. Nick Walker – GDE meeting Frascati 8.12.05 Formal Acceptance of BCD BCD EC Yeah! Wanna talk about it?

18. Nick Walker – GDE meeting Frascati 8.12.05 BCD Formal Acceptance The Role of Change Control  today is not the final word!  requests for modifications will now be formalised via the CCB  many questions and decisions on details still remain (not currently in the BCD document)  CCB will probably be more of an ‘Acquire Control Board’ in the first few months.