11 June 07 Fermilab Steering Group 1 ILC Baseline Schedule, Milestones, and Decision points Tom Himel

11 June 07 Fermilab Steering Group 1

ILC Baseline Schedule, Milestones, and Decision

points

Tom Himel


Preface

• There is a large amount of ongoing R&D.• I will concentrate on those aspects which

have major effects on the ILC design. • Note that ILC R&D, engineering, and

industrialization are all going on in parallel. • I’ll describe each R&D project with its goals,

explain why it is useful, give its schedule, and some results.

• We know many pieces of the schedule, but the fully integrated schedule will be developed during the EDR.


Contents

• Preview of Overall Schedule• Major risk mitigation R&D efforts:

– Cavity gradient– Cryomodule at full gradient– Linac string test– E cloud, DR kicker– BDS system test– Design for High Availability

• Cost reduction R&D– High power RF

• Construction Schedule and overview


Technically Driven Timeline

August

BCD

All regions ~ 5 yrs

Construction Startup

Siting Plan being Developed

2006 2010 2014 2018

RDR EDRBeginConst

EndConst

EngineerDesign

Site Prep

Site Select

R & D -- Industrialization

Gradient

e-CloudCryomoduleFull Production

System Tests

& XFEL

Detector Install

Detector Construct

Pre-Operations


Cavity Gradient – Goal

• Current status: Nine 9 cell cavities have been produced with gradients > 35 MeV/m. Not reproducible and needs several attempts at final processing.

• Goal: After a viable cavity process has been determined through a series of preparations and vertical tests on a significant number of cavities, achieve 35 MV/m at Q0 = 1010 in a sufficiently large final sample (greater than 30) of nine-cell cavities in the low power vertical dewar testing in a production-like operation e.g. all cavities get the same treatment.– The yield for the number of successful cavities of the final

production batch should be larger than 80% in the first test. After re-processing the 20 % underperforming cavities the yield should go up to 95%. This is consistent with the assumption in the RDR costing exercise.


Cavity Gradient – Plan

• There are three main activities which are closely coupled and partially progressing in parallel

– This is needed to separate cavity preparation and production issues• 1. Single-cell R&D

– Establishing more reliable final preparation parameters.– Focus on the final rinse after EP before HPR.– E.g. Ultrasound, Short EP (or HF rinse), H2O2

• 2. Tight-loop (Finish in 2008)– International multi-cell cavity exchange– 1st round

• Comparison of regional differences in preparation and testing– 2nd round

• Use single-cell results and implement on 9-cell cavities.

• 3. Production-like effort (Continues into 2010)– Monitor ongoing productions

• Esp. XFEL preparation• Use qualified and new vendors

– Use improved preparation process for an ultimate batch of cavities• A lot of data will be (is already) available by the time of the EDR writing


Cavity Gradient – Cost/Benefit

• Optimistic scenario with final batch + tight-loop– Costs 36 MILCU for the R&D– Gives highest confidence about the gradient

distribution

• This needs to be compared to:– A reduction of the average gradient for the ILC

from design of 31.5 to 28– ~ 600 MILCU


Cavity Gradient – Results

KEK single cell results:2005 – just learning2006 – standard recipe2007 – add final 3 μm fresh acid EPNote: multi-cells are harder than singles

2005

2007

2006


Module Test – Goal

• Intermediate goal– Achieve 31.5 MV/m average operational accelerating gradient in

a single cryomodule as a proof-of-principle. In case of cavities performing below the average, this could be achieved by tweaking the RF distribution accordingly.

– Auxiliary systems like fast tuners should all work.

• Final goal– Achieve > 31.5 MeV/m operational gradient in 3 cryomodules. – The cavities accepted in the low power test should achieve 35

MV/m at Q0 = 1010 with a yield as described above (80% after first test, 95% after re-preparation).

– It does not need to be the final cryomodule design


Module Test – Plan

• Enough good cavities for the cryomodules are expected from the cavity gradient program. Module assembly plans:

• DESY– 2007: M7: Being tested now. See next slide– 2007: M8: Probably no slow-down to select best cavities– 2008: M10 – could select best cavities from several regions

• US – funding problems have us behind schedule below– 2007 – Assemble a kit of parts from DESY to get first

assembly experience at FNAL– 2008 – assemble 2 cryomodules from US produced

parts. Second may be made by selecting the best available cavities.

– 2009 – build 2 more cryomodules

• Japan– 2009-10: Build, test, 3 cryomodules


Module Test – Results

DESY


String Test – Goal

• Build 1 RF unit (3 cryomodules + 1 Klystron) to fully check:– What gradient spread can be handled by LLRF system.

This test should be done with and without beam loading.– For heating due to high frequency HOMs.– Amplitude and phase stability.– Static and dynamic heat loads.

• To partially check:– Reliability– Dark current– for degradation or other weaknesses

• The ILC cryomodule is enough different than that of the TTF that a new system test is warranted.


String Test – Plan

• Use cryomodules built for module tests and for industrialization.

• Do more tests at TTF/FLASH• XFEL will both be a string test and provide costing,

contracting and construction information.• Build 1 RF unit at KEK and 1 at Fermilab.

– Do this in a phased manner, starting with smaller tests with modules that don’t meet specs.

– Full – to spec – RF unit should work before 1% of the final industrial production of ILC cryomodules is complete. (2014)

• There will be a larger second phase string test to verify quality of the modules going into the ILC.


String test – Cost/Benefit

• The risk if we don’t do the string test is that we will build ~1.5 BILCU of cryomodules and then discover a design flaw.

• Fixing them all could take years and easily cost more than 20% of the original cost.

• If there is a medium risk (25%) of this type of error then the risk*cost ~75 MILCU plus the loss of a few years in schedule.– Note the risk would be high 50-100% if not for

the TTF.

• The planned string tests will cost over 50 MILCU.


Schedule in Graphical Form2009 2012 2015 2018

ConstructionSchedule

CryomoduleProduction

RF System Tests


E cloud – Goal

• Ensure the e- cloud won’t blow up the e+ beam emittance.– Do simulations (cheap)– Test vacuum pipe coatings, grooved

chambers, and clearing electrodes effect on e- cloud buildup

– Do above in ILC style wigglers with low emittance beam to minimize the extrapolation to the ILC.


E cloud – Plan

• Grooved chambers and special coatings are being tested in PEP-II and KEK-B straight sections.

• Lots of simulations have been done and bench-marked against existing accelerators.– Still, the long extrapolation leaves us nervous.

• Plans are being developed to test special chambers in wigglers in CESR and KEK-B. – The funding is not yet assured for these more

definitive tests.– Schedule is for results in 2009


E Cloud – Cost/Benefit

• If we don’t do the R&D, there is a high (50%) risk that we have to build a second e+ DR at a cost of 200 MILCU. Cost*risk = 100 MILCU

• The first 2 types of R&D cost only a few million.

• The costs of the KEK-B and CESR tests are difficult to evaluate as they involve the dedicated use of the whole ring and it is unclear which costs should be accounted to the ILC. The scale is 10 MILCU.


E Cloud – Results

SLAC


BDS System Test – Goal

• Build ATF2, a scaled BDS prototype at KEK to test:– Optics design including never before done

local chromatic correction– Keeping a beam small (35 nm) and stable to a

few nm for days at a time– Laser wires– Intra-train feedback– BPM’s– High availability power supplies– Tuning algorithms


BDS System Test – Plan

• ATF2 is already under construction by a multi-regional collaboration.

• Will be commissioned in 2009 with optics tests done in 2010


BDS System Test – Cost/Benefit

• Cost is ~5 MILCU• Ameliorates a medium (25%) risk of having to

do a major BDS redesign that could lengthen the BDS and cost 200 MILCU extra

• Would be a bargain at twice the price


High Power RF – Goals

• The baseline HPRF design is mature and has very little risk.

• The R&D concentrates on cost reduction– A Marx modulator to replace the bouncer

modulator– Modified RF distribution system– Sheet-beam klystron to replace multi-beam

klystron

• If all are used, the HPRF cost is cut in half.


Marx Modulator – Results

SLAC


Marx Modulator – Results

100kV Output –1400 μsec, Leveled

Long term test planned in coming year.

SLAC


Modified RF Distribution System – Plans

SLAC


Sheet Beam Klystron – Plan

• Build beam tester and klystron by Summer 2008

• The beam tester will validate 3-D beam transport simulations and allow a more rapid turnaround for electron gun changes

• The klystron will be developed in parallel with little feedback from the beam tester. A rebuild of the klystron can incorporate design changes motivated by the beam tester


Sheet Beam Klystron – Plan


Americas Site Plan


~ 5.5 km

~ 5.5 km

Central Area fits inside the Fermilab boundary

Site Characterization of the Central Area can be done

~ Boundary of Fermilab

Preconstruction Plan for Fermilab


Preparing for 2012 Construction Start2007 2010 2012

Phase 1

Phase 2

Phase 3


Civil Construction Timeline


Technically Driven Timeline (reprise)

August

BCD

All regions ~ 5 yrs

Construction Startup

Siting Plan being Developed

2006 2010 2014 2018

RDR EDRBeginConst

EndConst

EngineerDesign

Site Prep

Site Select

R & D -- Industrialization

Gradient

e-CloudCryomoduleFull Production

System Tests

& XFEL

Detector Install

Detector Construct

Pre-Operations

Documents

11 June 07 Fermilab Steering Group 1 ILC Baseline Schedule, Milestones, and Decision points Tom Himel