CLIC rf structure program

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.

CERN MTP (draft) for 2012-2016

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!

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

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 2007. 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.

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.

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

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.

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).

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 2012-2016 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:

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

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 2012-2016 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:

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 0.25 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 2012-2016 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

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:

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 2012-2016 Task4 Construction of x-band structures and TBA assemblies Parts for needed x-band structures, metrology and assembly of TBAs 2013-2016 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

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)