Prsentation PowerPoint
May 28th 20121
A RD 05:SURFACE PREPARATION STUDIESFOR SUPERCONDUCTIVE CAVITIES
F. Eoznou, T. Saeki- F. Eozenou / T. Saeki - A_RD_05CEA DSM IrfuCEA DSM Irfu
May 28th 2012 - F. Eozenou / T. Saeki - A_RD_052CONTEXT
CEA DSM Irfu
May 28th 2012- F. Eozenou / T. Saeki - A_RD_053MembersIrfuKEKLeader: Eoznou FabienLeader: Takayuki SaekiVisentin BernardHitoshi HayanoBerry StphaneKen WatanabeAntoine ClaireShigeki KatoMasashi YamanakaMotoaki SawabePARTICIPANTS
Visit Saeki San & Yamanaka San @ Saclay in March 2012CEA DSM Irfu
May 28th 2012- F. Eozenou / T. Saeki - A_RD_054SURFACE TREATMENTS FOR LARGE SCALE CAVITY PRODUCTIONInternational Linear Collider~16000 Superconductive Niobium cavities > 31.5 MV/m
Improvement of the preparation of the SC Nb cavitiesCleaning of the surfaceReparation of defectsIncrease in the reprocubility of the processCost reductionIndustrialization
Cavity tratment/exchange programSample treatments/analysis
CEA DSM Irfu
May 28th 2012- F. Eozenou / T. Saeki - A_RD_055EXAMPLES OF CONTRIBUTION WITHIN TYL
CEA DSM Irfu
May 28th 2012- F. Eozenou / T. Saeki - A_RD_056LOCAL GRINDING AT KEK
CCD cameraLEDHead : Diamond seat Motor (3000 rpm)Grinding machine
Scratches on iris After grinding
CEA DSM Irfu
6May 28th 2012- F. Eozenou / T. Saeki - A_RD_057
Recovery of the cavity after local grinding of the defects at iris.grindingIMPROVEMENT AFTER GRINDING OF DAMAGED CAVITY
RF test of damaged 1CellTest after grinding and EPCEA DSM Irfu
May 28th 2012- F. Eozenou / T. Saeki - A_RD_058
Poly-Ethylene (PE) spongewipe handleSponge mechanicsInsertionSponge ExpansionandWipe by rotationUPW + detergent inletUPW + detergent outlet
PE spongeSET-UP FOR SPONGE WIPING ON SINGLE-CELL
CEA DSM Irfu
8May 28th 2012- F. Eozenou / T. Saeki - A_RD_059RESULTS ACHIEVED WITH SINGLE-CELLTest with a good cavity (Eacc>35 MV/m, no FE)Sponge wipe at KEKVT at SaclayThe performance of the cavity is maintainedThe process do not deteriorate performance
Tests in challenging conditions (FE limited cavity)No improvement achievedBut suspicious cleaning sequenceExperiment will be repeated
CEA DSM Irfu
May 28th 2012- F. Eozenou / T. Saeki - A_RD_0510Field flatness degradation experimentally observed at KEK after electropolishing,How can modelling help us understand (and solve) the problem?
Fluid velocity[HF] at 4 000 s[HF] at 20 000 s Good electropolishing of central cell #5
Electro-polishing will depend on the cell location for others
Electropolishing needs to be improved in the other cells
HFmol/m3Velocity m/sTESLA CavitiesMODELLING OF ELECTRO-POLISHING (Saclay)
CEA DSM Irfu
May 28th 2012- F. Eozenou / T. Saeki - A_RD_0511SURFACE CONTAMINATION ANALYSIS OF SAMPLESSamples EPed at KEK & SaclayAnalysis at KEKSame contaminants found (S, F, C)More sulfur @ KEKInfluence of anode-cathode distance?
Experiments to be continued
Surface Analyses (XPS)Surface Analyses (Auger/AES)Surface Analyses (SIMS)
CEA DSM Irfu
May 28th 2012- F. Eozenou / T. Saeki - A_RD_0512NEW EQUIPMENTS, NEW CHALLENGES
CEA DSM Irfu
May 28th 2012- F. Eozenou / T. Saeki - A_RD_0513VERTICAL EP (VEP) AT CEA SACLAY
CEA DSM Irfu
May 28th 2012- F. Eozenou / T. Saeki - A_RD_0514
3 cm
EVOLUTION OF EP @ CEA SACLAY2004: Experiments on flat samples:2006: Operation of 1Cell Horizontal EP set-up2011: Operation of Vertical EP Set-up
CEA DSM Irfu
May 28th 2012- F. Eozenou / T. Saeki - A_RD_0515
September 2011: Commissioning, Tests with waterOctober 2011: Connections to exhausts, tests with acid in novemberJanuary 2012: Area closed. Final configuration.EVOLUTION OF THE VEP SET-UP
CEA DSM Irfu
- F. Eozenou / T. Saeki - A_RD_0516
HORIZONTAL VS VERTICALPros:Good evacuation of gases (cavity half filled)Demonstrated efficiencyLarge range of parametersCons:Complicated processRotary sealsSwitching of the cavityLow removal ratePros:Simple processLow floor surfaceImproved safetyHigher removal rateCons:Sensitive to fluid dynamicsProper parameters to be determinedVoltage and fluid velocityMay 28th 2012
CEA DSM Irfu
rZ
VERTICAL CONFIGURATION AND MODELLINGCathodeFzConfiguration simpler in VEP case:Symmetry according to z-axis
2D axisymmetry model
Fluid velocity[HF] at 4 000 s[HF] at 20 000 s Modelling of horizontal EP:Difficult: no symmetryHints for non uniform polishing- F. Eozenou / T. Saeki - A_RD_05May 28th 2012
CEA DSM IrfuCEA DSM Irfu
Gravit est invariant en rotation autour de laxe z15 volts appuy entre la cavit et la cathode
1718EXAMPLE OF MODELLING
Modelling (COMSOL) with rod cathodeArea close to the cell poorly swept with SPL cavitiesNeeds improvement
Electrolyte velocity: m/sFlow profile from the cathode to the cavity:Fluid velocity m/s Vs xFluid velocity m/s - F. Eozenou / T. Saeki - A_RD_05May 28th 2012
CEA DSM Irfu
19Modified Cathode Shape (SPL cavity)VEP WITH CIRCULATING ACID SHOULD NOT BE CELL DEPENDENTSHAPED CATHODE MAKE IT POSSIBLE TO IMPROVE THE FLOW
Example of fluid modelling with alternative shapeFluid velocity m/sFluid velocity m/s Vs xFluid velocity m/s - F. Eozenou / T. Saeki - A_RD_05May 28th 2012
CEA DSM Irfu
20
Parameters for 1st VEP sequence:
- 3 hours VEP- Shaped and masked cathode- 8 L/min acid flowrate, Nitrogen blowing- 20 V- Temperature < 26C
FIRST VEP WITH 1CellBenefits from VEP: operator friendly!
No flaw observed during the first VEP sequenceEasy preparation of the cavity (time saved + security)More efficient rinsing procedures Very stable process Adapted to industry - F. Eozenou / T. Saeki - A_RD_05May 28th 2012
CEA DSM Irfu
Bright SurfaceBrighter on top half-cell but bubble traces
20 V = Oxygen generationRESULTS AFTER EPV A 20VAcid flow (8L/min) not sufficient to stir the gas- F. Eozenou / T. Saeki - A_RD_05
+Ar Baking 3hx145CMay 28th 2012
CEA DSM Irfu
22EPV WITH LOWER VOLTAGE (12V)
No obvious bubble trace at the upper cellBrightening of the surfacePromising Voltage
Waiting for the RF Test of the cavity- F. Eozenou / T. Saeki - A_RD_05May 28th 2012
1Cell Vertically EPed at 12V. Improvement of the surface.CEA DSM Irfu
- F. Eozenou / T. Saeki - A_RD_0523NEW CAVITY FABRICATION FACILITY AT KEKMay 28th 2012
CEA DSM Irfu
Introduction of KEK activitiesThe fabrication-cost reduction of superconducting cavity is not enough for future project like ILC. We have constructed a new superconducting Cavity Fabrication Facility (CFF) at KEK for the study of cost-effective mass-production of cavity.All the necessary equipment for the cavity fabrication were installed in the CFF at KEK.We have fabricated 9-cell cavity KEK-00 (without HOM) in CFF. The fabrication process of KEK-00 and the vertical test result of KEK-00 will be shown.Future plan of CFF will shown as well as the plan of FJPPL collaboration between Saclay and KEK.2425Main Equipments of Cavity Fabrication FacilityInspection equipment for Nb surfaceEBW room Installation of EBW machine started from April 2011.Vertical lathePress machine (servo control)
Measuring system for half cell shape (Under developing)Chemical Polishing room
30 June 20114 Dumbbell, 8 Dumbbell EBW at Job-shop (June 2011 July 2011)
BeamBeam8 July 20116 July 201126
Fabrication of KEK-00 Cavity (w/o HOM)
Center cells (Nb) / EBW at job shopDumb-bell (Nb)Beam-pipe (Nb)End-cells (Nb)
Input-port pipe (Nb)
End-Plates (Ti) + Nb ringBeam-pipe (Nb)End-Plates (Ti) + Nb ringFlanges (Nb-Ti alloy)27Final EBW at Equator of End-Cell at Job Shop1 Dec. 2011Failure in the EBW at the equator of end-cell (cell#1)/ 120 kV, 30 29 mA.
VoltageBeamCurrentPosition of hole
Cell#128
The setup of EBW of KEK-00 to repair the hole of cell#1. Repair of 9-cell cavity KEK-00 by EBW30 Jan. 2012 (Mon.)
Small Nb piece was made and it was set into the hole.EBW29
EBW with 120kV, 20mA, and 5 mm/s.EBW beadEBW bead
Observation of repaired part and local grindingA picture of repaired part: inner surface of cell#1-equator, theta=237 deg. (1st Feb. 2012)
EBW beadEBW beadArea of EBW for repairing the hole of cell#1Observation by Kyoto camera
Local grinding was done for the inner surface of the repaired part of cell#1 by hand in order to make a smooth surface. (3 Feb. 2012).3031Surface treatment of 9-cell cavity (KEK-00)
Bulk EP (100 um), Degreasing (50 0C, 30 min), HPR (1.5 h), Annealing(4 h, 750 0C), and final EP (20 um).HPR (7 hours)Brushing of beam-pipe and HOM antenna.Degreasing with detergent (FM-20 2%) in hot bath (500C, 30 min).
BrushingVertical Test Result of 9-cell cavity w/o HOM (KEK-00)32
Cell#1 (repaired cell) reached to 42.7 MV/m in the 6pi/9 mode. Limitation in the pi mode might be quench at cell#8, because the T-mapping sensor detected higher temperature in cell#8 in coincidence with the quench at 29 MV/m.Eacc = 29 MV/mQ0 = 9 x 10^933Future Plan of Cavity Fabrication Facility (CFF) ActivitiesFY 2011FY2012 9-cell cavity: KEK-00 without HOMApril 9-cell cavity: KEK-01 with HOMMachining of all parts by KEKEBW of all seams at CFF(KEK)AprilFabrication 9-cell cavities: KEK-02 with HOMSingle-cell cavity for FJPPL collaborationSurface preparation and VTSurface preparation and VTStudy for the high-pressure code applicationThis cavity will be used for the vertical EP test at Saclay.FabricationFabricationSummary of KEK activitiesAll equipment (press machine, CP room, EBW machine, etc) were installed in Cavity Fabrication Facility (CFF).
9-cell cavity KEK-00 (w/o HOM) was fabricated. Center cells were EBWed at job shop and end-groups were EBWed in CFF(KEK).
Final EBW of KEK-00 cavity at the equator of end-cell was failed, but it was repaired. After surface preparation at KEK, KEK-00 reached to Eacc = 29 MVm in vertical test. 9-cell cavity KEK-01 and -02 (w/ HOM) will be fabricated where all seams will be EBWed at CFF(KEK) in FY2012.
We will fabricate a single-cell cavity in CFF at KEK. This cavity will be used for the study of vertical EP at Saclay in the frame-work of FJPPL collaboration.
3434- F. Eozenou / T. Saeki - A_RD_0535OBJECTIVE FOR FY 2012May 28th 2012
CEA DSM Irfu
Plan of Collaboration with Single-Cell Cavity36Fabrication of a single-cell cavity at CFF(KEK). This cavity will be used for the study of vertical EP at Saclay in the frame-work of FJPPL collaboration.
Fabrication of single-cell cavity at CFF(KEK).Vertical EP of the cavity and vertical test at Saclay.
May 28th 2012- F. Eozenou / T. Saeki - A_RD_0537
ON-GOING SAMPLES EXPERIMENTS
Same contaminants observedQuantities differ (Sulfur)More sulfur found at iris at KEKElectrodes configuration incriminated EP @ KEK. Rotating Nb samples.EP @ Saclay. static Nb samples.Samples measurements on cavities @ KEK.4 samples will be EPed, 4 different anode-cathode distance (Saclay)Packing in Cleanroom in dedicated boxAnalysis of samples (KEK)
CEA DSM Irfu
37May 28th 2012- F. Eozenou / T. Saeki - A_RD_0538
COMPARISON HEP/VEPHEP @ KEKVEP @ Saclay2 advanced equipmentsEfficiency of HEP demonstratedExperience necessary for VEPUnique opportunity for fruitful comparison
KEK HEPed cavity shipped to SaclayVEP @ SaclayVT @ SaclayComparisonCEA DSM Irfu
May 28th 2012- F. Eozenou / T. Saeki - A_RD_0539ON-GOING GRIDING/WIPING EXPERIMENTS
KEK Grinder makes it possible to treat equator and irisNew head under development to reach any part of a cellSaclay Cavity with pits sent to KEKLocal grinding of the defectsCavity shipped back to Saclay for VT
Additional sponge-wiping of contaminated cavity
Saclay cavity with pitsSaclay cavity with FEKEK grinding systemKEK wiping systemCEA DSM Irfu
40THANK YOU FOR YOUR ATTENTION- F. Eozenou / T. Saeki - A_RD_05May 28th 2012
CEA DSM Irfu