Accelerator RFQ system AnneCatherine CHAUVEAU for the ESS

Accelerator RFQ system Anne-Catherine CHAUVEAU for the ESS RFQ Team at CEA Saclay www. europeanspallationsource. se April , 2016

RFQ system Overview Pick-ups (x 28) 5 sections Tuners x 60 Pumping system (x 36) RF Couplers x 2 Partial RF distribution system Cooling connector x 80 Tuned and conditioned RFQ on its support MAIN GOALS of the RFQ : q Bunch the proton beam at the frequency of 352. 21 MHz q Accelerate the beam from the exit of the source at 75 ke. V up to 3. 6 Me. V q Provide optical characteristics to the beam in order to avoid losses at higher energy. Planning q Start date: Kick Off “Warm Linac Internal Review 21 -06 -14 q Completion date: Ready for transportation to ESS Lund 13 -03 -18 q Completion date: Formal transfer after conditioning operations in ESS tunnel 18 -07 -18 Water cooling system 2

RFQ system Schedule Coupler tender Coupler manufacturing Test cavity assembly Tuner proto manufacturing PI tender Coupler test and conditioning Test cavity body leak test Test cavity and auxiliaries Manuf. /brazing IO plates tender Aux. copper manufacturing Poles copper manufacturing RFQ tender IO plates manufacturing IO plates finger brazing HIP Process Qualification Section 1 Machining Section 1 Ass. /Braz Sec 2 Mach. Sec 2 Ass. Braz. Section 1 assembly. Sec 3 Mach. Sec 3 Ass. Braz Section 1&2 assembly. Sec 4 Mach. Sec 4 Ass. Braz Section 2&3 assembly. Sec 5 Mach. Sec 5 Ass. Braz Sec 5 Ass RFQ ass. RF Test De-ass +packing Section 3&4 assembly. Transport Tuner Manuf. Tuner tender SAR 1 13/03/18 Re-Ass. Cooling system tender SKID syst packing SKID syst manuf. PLC order PLC manufac turing PLC progra mming SKID syst transport SKID syst tunnel inst. Condition. SAR 2 16/07/1 8 3

RFQ Technical performances Main requirements: To reach these performances, ESS and CEA have already put up the followings: • • Detailed Beam analysis study and simulations Detailed RF design studies and simulations Detailed thermal aspect study and simulations Detailed mechanical studies Detailed cooling system analysis Complete requirement definition Permanent interface definition and follow-up Other requirements: Ø Ø Ø Ø L 3 L 4 Electromagnetic Resonators L 4 Vacuum L 4 WTR (Water) L 4 RFDS (RF Distribution System) L 4 LLRF (Low Level RF) L 4 CIC (Control command) Alignment Remaining tasks to fulfill these requirements: • • Close follow up of all manufacturer process and progress Several measurements and leak tests throughout RFQ manufacturing (Bead-Pull for voltage law and 3 D measurements) 4

RFQ System Selected technologies Deliverables Tuned and conditioned RFQ on its support, RF distribution system, water cooling skid RF design four-vane structure, naturally stable single segment tunable devices: end rods, vacuum ports, slug tuners, RF couplers Fabrication of RFQ modules 4 electrodes with modulations and apertures for ancillaries one step of copper-copper brazing in vertical position (IPHI) 5 modules with length < 1 m in agreement with demonstrated technology Brazed vacuum ports avoid machining of grids in the vanes accurately positioned after electromagnetic measurements, prior to braze (Linac 4, IPHI) RF couplers loops offer less power dissipation and voltage ripple (Spiral 2) small coaxial window standard tuner port allows coupling adjustment at final Q Adjustable slug tuners performances achieved at last tuning step are saved under vacuum allow for last minute corrections, after transport for instance no delay required for machining after last tuning step 5

RFQ System Selected technologies RF distribution one Power divider, one power load and two feeders loops in 90° quadrants tuned to minimize voltage perturbation phasing trombone to minimize reflection coefficient Voltage profile monitoring 5 4 pick-ups will allow reconstruction of voltage profile check RFQ voltage integrity vs. time voltage profile corrections are possible to some extent Spiral 2 RFQ untuned Transition (with SMS connector) Flexible waveguide Reflectometer Coupler Spiral 2 RFQ: tuned with copper slugs Water cooling dedicated skid with four independent circuits independent control of frequency and voltage function eventually useful for voltage corrections 6

RFQ system Integration and Verification Plan RFQ • Test cavity ports are identical to RFQ ports and used as ports prototypes • Brazing and drilling mock-ups for manufacturer qualification • Vacuum and water leak tests done several times during processing • Bead-Pull and 3 D measurements after poles assembly and before and after cu-cu brazing • Sections tested at Saclay in parallel with other sections manufacturing • Assembly process partially validated early at Saclay • Pre-RF tuning of the RFQ done in Saclay prior shipping to Lund RF loop (coupler = window + loop) • Several partial Mock-ups for manufacturer qualification (ceramic brazing and Ti. N coating) • Leak test and 3 D measurements during manufacturing steps. • Low power RF tests (to check windows manufacturing) at Saclay with the test cavity Test cavity: 2 RF power loops, 1 vacuum port, 1 tuner port Bead-Pull measurement Adjustable slug tuners • One innovative prototype ordered prior to main tuner tenders (back-up solution is available) • Bellow brazing qualification of manufacturer • Verification of behavior under pressure on the test cavity • 3 D measurements, leak tests, RF tests with test cavity Cooling system • Factory FAT using simulated load Test cavity test stand 7

RFQ Organization at CEA partner lab Project Management Office is in charge of the organisation of the CEA-ESSI project and manages the interfaces with ESS management as well as Management plan, configuration management, project Quality management, performance and progress dashboard followup and non conformity management. RFQ WU lead by Bruno Pottin is responsible of: Ø The Design Ø The development Ø The realisation and manufacturing Ø And the performance validations of the RFQ system Under the supervision of the ESS Project Management Office of CEA/IRFU 8

RFQ Budget and cost-book 9

RFQ system Major Procurements Delivery to Lund due 13/03/18 Formal Handover due 16/07/18 TUNER COUPLERS TEST CAVITY and AUXILIARIES PROTOTYPING COUPLER CONDITIONING COPPER RFQ MANUFACTURING Assembly in Saclay will start in parallel with sections manufacturing RFQ ASSEMBLY and TESTS MPP planning is more than 200 lines Manufacturer’s planning awaits confirmation RFQ PACKING and TRANSPORT RFQ RE-ASSEMBLY and CONDITIONING 10 10 | PAGE

RFQ system Top risks RISKS LEVEL BEFORE MITIGATION 9 6 Level 64 4 Level 32 Level 16 Risk level 0 0 Level 8 level 4 10 8 6 4 2 0 Number of risks 10 8 6 4 2 0 RISKS LEVEL AFTER MITIGATION 7 8 3 0 Level 64 Level 32 Level 16 Risk level Level 8 1 level 4 No “Very High” level risks after mitigation Ø Main risks linked to time schedule as it contains no margin and is very tight Risk that manufacturers do not succeed the 20 months challenge Risk of overcost due to late validations in the tunnel instead of Saclay (First complete test of the RFQ will be done in the tunnel. Only partial validations are done in Saclay before delivery to ESS) -> Maximum validations done in Saclay Risk on tenders meeting points especially auxiliaries Vs RFQ cavity -> Tight tracking of manufacturer progress Ø Risk of overcost due to request for short manufacturing delays Ø High technical risks on coupler manufacturing and on coupler not reaching requested power because coupler is very complex and power requirement is very high -> Manufacturer mock-up qualifications and 1 spare coupler 11

Next Six Months • • • Schedule signature All main tenders should be signed shortly (RFQ, test cavity and auxiliaries and couplers) Focus is now moved to supports and assembly tools Cooling system specification done at 95% and tender started Tuner prototype due before end of april Test and validation specifications 12

RFQ system Summary Schedule is very tight. Strong tendering activity made difficult because of short schedule and ESS transformation into an ERIC Very high level of technology for RFQ and RF couplers But still on track for the moment 13