Post on 12-Jan-2016
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Nick Walker – GDE meeting Frascati 8.12.05
Discussion and Approval of the BCD
Nick WalkerILC-GDE
Frascati – 8.12.2005
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
Nick Walker – GDE meeting Frascati 8.12.05
Arriving at the BCD
1st ILC Workshop at KEK (11.2004) working groups (WG) formed to begin identifying
contentious design issues 2nd 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
2nd Snowmass week: concentrate on the list of ‘Top 40’ critical design questions (Himel List)
Nick Walker – GDE meeting Frascati 8.12.05
Arriving at the BCD (cont)
Comments on Snowmass first week: formal workshop with traditional
parallel working groupssecond-week: entire ILC community not
present, but those that remain make significant progress on identifying baseline.
It was understood that the result of 2nd week deliberations did not necessarily reflect the consensus
view of the entire community.
Nick Walker – GDE meeting Frascati 8.12.05
Arriving at the BCD (cont)August September October 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):BarishDugan, Foster, Takasaki (regional directors)Raubenheimer, Yokoya, Walker (acc. design leads)
Nick Walker – GDE meeting Frascati 8.12.05
Arriving at the BCD (cont)August September October 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 commentand feedback
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)
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
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
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 ~1m linac BPM resolution
(current BCD is ‘less than 10m’) Gudrid Moorgat-Pick
Importance of focus on CME ≤ 500GeV (strong physics case) Concerns on potential 1TeV upgrade driving initial design
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 5×1034machine 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
Nick Walker – GDE meeting Frascati 8.12.05
The Baseline Machine (500GeV)
Nick Walker – GDE meeting Frascati 8.12.05
1TeV upgrade
Nick Walker – GDE meeting Frascati 8.12.05
The Baseline Machine (500GeV)
not to scale
~30 km
e+ undulator @ 150 GeV (~1.2km)x2R = 955m
E = 5 GeV
RTML ~1.6km
ML ~10km (G = 31.5MV/m)20mr
2mrBDS 5km
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)
Nick Walker – GDE meeting Frascati 8.12.05
Formal Acceptance of BCD
You got a problem with
that?
BCD EC
Nick Walker – GDE meeting Frascati 8.12.05
Formal Acceptance of BCD
BCD EC
Yeah!Wanna talk
about it?
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 CCBmany 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.