1. CLIC rf structure program

2. CLIC today
Most feasibility issues for CLIC have been demonstrated, with good momentum on remaining open issues e.g. TD24, CTF3, stabilization.
CDR writing underway (sigh).
Linear collider (CLIC+ILC+accelerator+detector) study leader at CERN – Steinar Stapnes
Solid support from CERN management.
Next phase, with roughly five year time-scale, to move towards project is being planned.
Working assumption – consistent with CERN MTP (Medium Term Plan) + 30% contributions from collaborators.

3. CERN MTP (draft) for

4. rf structures today
Individual structures basically achieving specifications, both PETS and accelerating structures.
Almost have baseline structure – some features still need to be demonstrated like accelerating structure compact couplers, include SiC loads.
Structure fabrication at KEK/SLAC, CERN and soon Saclay.
Testing at NEXTEF, NLCTA, ASTA, CTF3 and CERN klystron. Critical – no structure under test today!

5. Main areas for next stage 1
Fully establish baseline structure - Test of fully featured CLIC_G. Remaining features are TD24, compact power couplers and SiC loads. Check dynamic vacuum (tricky). Verify tolerances, wakefield monitor performance and long range wakefield suppression.
Statistics – We need numbers for production yield and to verify long-term behavior.
Significant increase in high-power testing capability – at least 6 test stands operating in parallel.
Machining/metrology infrastructure – At CERN or at collaborating laboratory for better in-house insight into key technologies.
Cost studies
Integration into modules

6. Main areas for next stage 2
Re-optimize high-gradient design – We only now have high-gradient data that really lets us do this. Current design made end This will probably be done while re-optimizing for an intermediate energy CLIC. Easily room for O(10%) effects in efficiency and cost. Need to understand effect of beam loading, experiment planned.
Optimize process – Deeper understanding of breakdowns ready to help us optimize machining, chemical surface treatment, heat treatments and conditioning strategy. We have something that works but there is the potential to reduce conditioning time and save lots of money.
Other types of X-band structures – Structures optimized to intermediate/early stage energies, crab cavity and bunch compressor cavity.

7. Main areas for next stage 3
Alternative baseline designs – We followed a path to get the highest gradient earliest. Not obvious if this gives highest performance, cheapest structure. Ongoing activities are DDS with Manchester and choke mode with Tsinghua. Are we in a local or a global optimum?
Fundamental breakdown studies –Guide rf design through high-power scaling laws, process optimization and testing. Excellent training for young people, ties in diverse collaborators.
Exotic structures – Alternative materials, standing wave, speed bumps, recirculation etc. Still the potential for a breakthrough. Depending on LHC results a 3 TeV range machine may be proceeded by two lower energy stages – which means decades to get some of this stuff to work.
Outreach – Good to spread X-band and high-gradient technology to other applications. Increased experience, increased credibility and lower cost. Obligation to give return on our R&D.

8. CLIC collaborations with other projects
XFEL energy linearization – PSI and Trieste
XFEL compact 1 kHz nc linac – Groningen
High-gradient normal conducting cavities for carbon ion acceleration – TERA
High-gradient normal conducting cavities – Muon collider
High-gradient superconducting cavities – ILC

9. A scenario for high-power testing
In my personal opinion increasing our testing capability is the most crucial issue we currently face. If we have enough test slots the rest will follow.

10. Work package planning
I will now show the technical program broken down into DRAFT work packages.
The work packages will be used to plan resources with CERN departments and groups and to establish and structure collaborations.
The packages are NOT in their final form. On the largest scale they are getting close, details are not always so good (which doesn’t really matter).

11. X-band Rf structure Design
WP: RF-design
Purpose/Objectives/Goals
Deliverables
Schedule
Task 1: Design of accelerating x-band structures
Contribution and follow-up to parameter evolution of CLIC project; optimization of designs for gradient and low breakdown rate:
Optimize heat treatment and chemistry, optimized conditioning, machining stresses, roughness and BDR, wakefield measurements, pulsed surface heating investigation, couplers, special rf tests etc.
Better designs, new designs for new construction scenario
or energy staging
Task2: Design of PETS
Refinement of designs, optimized ON/OFF
Task3: Design of auxiliary components
WFM, Rf networks, breakdown monitors
Task 4: test definition and analysis
Contribution to definition of high power test program, contribution to data analysis, integration of test results
Link to other WPs/activities:
Lead collaborator(s):
Resources:
2011
2012
2013
2014
2015
2016
Total
M (kCHF)
200
250
300
1350
M>P (kCHF)
P<M (FTE) 4 5 6 27
Fellows (FTE) 3 19
CERN Personnel (FTE): 2 10
Resources comment:

12. X-band Rf structure Production
WP: RF-xprod
Purpose/Objectives/Goals
Deliverables
Schedule
Task 1: Construction of baseline accelerating structures
Test structures for statistical and long term high-power testing with all damping features and high power couplers
3 generations of test structures, total quantity 48, total cost 6 MCHF.
12 in 2013
24 in 2015
12 in 2016
Task 2: Supply of small series development prototypes and/or medium power test structures
Test structures for full features (4), wakefield monitor equipped (4), optimized high-power design (8), different machine energy optima (4), optimized process (8), develop DDS (2) and choke (2), compressor (2)
Typically 12 variants in series of 4 structures each, total quantity 40, total cost 6 MCHF.
8 structures per year
Task 3: Supply baseline PETS (note: most PETS fabrication accounted elsewhere, e.g. TBL)
PETS for statistical and long term high-power testing
4 PETS, total cost 0.2 MCHF.
3 in 2013
1 in 2015
Task 4: PETS for ON/OFF testing
PETS for on/ off test
2 generations 0.1 MCHF
Task 5: Baseline to pre-series development
Take the fully tested x band rf Systems and evolve their production techniques to an industrialized process
2015 onwards
Resources:
2011
2012
2013
2014
2015
2016
Total
M (kCHF)
3500
3600
3800
3900
18300
M>P (kCHF)
500
600
700
3000
P<M (FTE) 6 8 9 30
Fellows (FTE)
CERN Personnel (FTE): 2 10

13. X-band Rf structure High Power Testing
WP: RF-xtesting
Purpose/Objectives/Goals
Deliverables
Schedule
High power testing of x band structures
Establish in collaboration with designers and producers a test-schedule for the facilities at CERN, KEK and SLAC
Organize manpower for the tests
define consolidation and repair needs
lead the data analysis of the tests
suggest changes to designs and/or fabrication
Structure Tests
Analysis of results
Link to other WPs/activities:
Lead collaborator(s):
Resources:
2011
2012
2013
2014
2015
2016
Total
M (kCHF)
200
250
1200
M>P (kCHF)
P<M (FTE) 4 5 24
Fellows (FTE) 3 18
CERN Personnel (FTE): 1 2 8
Resources comment:

14. Creation and Operation of x-band High power Testing Facilities
WP: RF-Testfac
Purpose/Objectives/Goals
Deliverables
Schedule
Task 1: High-power test stands
6 new klystron-based test stations with approximately 140 MW peak power each.
6 test stands. Cost of 0.5 MCHF per modulator, 1 MCHF per 50 MW klystron, 0.5 MCHF infrastructure. Total cost 12 MCHF plus operation.
2 in 2013
2 in 2014
2 in 2015
Task 2: Medium power, high rep rate test stand
2 test stands with 4x80 MW 100 Hz slots based on four 5 MW klystrons.
2 test stands. Cost of MCHF per modulator, 0.1 MCHF per 5 MW klystron, 0.25 MCHF infrastructure. Total cost 1.8 MCHF.
1 in 2013
1 in 2014
Task 3: Test stand operation
Operation of high power test facility at CERN: Provide high uptime, schedule maintenance and repair periods. Link to other test facilities.
Maintenance of installation, crews for maintenance
Link to other WPs/activities:
Lead collaborator(s):
Resources:
2011
2012
2013
2014
2015
2016
Total
M (kCHF)
500
4200
5400
16000
M>P (kCHF)
100
200
1400
P<M (FTE) 2 3 7 21
Fellows (FTE)
CERN Personnel (FTE): 1 5

15. Basic High Gradient R&D & Outreach
WP: RF-R&D
Purpose/Objectives/Goals
Deliverables
Schedule
Task 2: dc spark test areas
10 kHz range, scanning, fully instrumented dc spark systems
2 systems for a total cost of 0.5 MCHF
Task 3: Theoretical and experimental studies of high-gradient and high-power phenomena
Basic understanding of high-gradient and high-power phenomena including breakdown, pulsed surface heating, high-power rf design dynamic vacuum and dark current.
Task 4: Application of high-gradient and high-frequency technology to other projects
Create technology base for compact normal conducting accelerators.
Task 5: Beam-based experiments e.g. FACET
Define and follow up beam based experiments such as long-range wakefield measurements.
FTEs accounted elsewhere
Link to other WPs/activities:
Lead collaborator(s):
Resources:
2011
2012
2013
2014
2015
2016
Total
M (kCHF)
350
1750
M>P (kCHF)
300
1500
P<M (FTE) 4 20
Fellows (FTE)
CERN Personnel (FTE): 2 10
Resources comment:

16. Creation of an “In-House” TBA Production Facility
WP: RF-xTBA-Fac
Purpose/Objectives/Goals
Deliverables
Schedule
Task 1:
Collect requirements for an CLIC x-band CERN production site; identify possible locations
Project proposal, site proposal
2011
Task2
Detailed list of requirements, balance between continuous outsourcing and CERN in-sourcing
(include alignment and stabilization?), metrology, brazing, high precision machining, surface treatment
Choice of location, budget approval including EN part
2012
Task 3
Construction of site
Staged completion of site
Task4
Construction of x-band structures and TBA assemblies
Parts for needed x-band structures, metrology and assembly of TBAs
Link to other WPs/activities:
Lead collaborator(s):
Resources:
2013
2014
2015
2016
Total
M (kCHF)
200
2000
4600
M>P (kCHF)
100
800
P<M (FTE) 3 2 10
Fellows (FTE)
CERN Personnel (FTE): 1 5

17. Overall material total 38.6 MCHF (out of 85.6x1.3=111 MCHF)
Miscellaneous RF
WP: RF-misc
Purpose/Objectives/Goals
Deliverables
Schedule
Task 1: Main beam rf systems for injector and booster linacs.
Design main beam injector and booster linac rf systems and launch appropriate hardware studies and tests.
Link to other WPs/activities:
Lead collaborator(s):
Resources:
2011
2012
2013
2014
2015
2016
Total
M (kCHF)
M>P (kCHF)
P<M (FTE)
Fellows (FTE)
CERN Personnel (FTE):
0.5
2.5
Resources comment:
Overall material total 38.6 MCHF
(out of 85.6x1.3=111 MCHF)