Fabrication of CLIC X-band RF structures and RF components
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[email protected] 21-Oct-2010 Holland@CERN Fabrication of CLIC X-band RF structures and RF components G. Riddone OUTLINE ° Two-beam module ° RF accelerating structures ° Power extraction and transfer structures ° RF components
Transcript of Fabrication of CLIC X-band RF structures and RF components
10-Nov-2010 1 Holland@CERN21-Oct-2010 Holland@CERN
Fabrication of CLIC X-bandRF structures and RF components
G. Riddone
OUTLINE° Two-beam module ° RF accelerating structures° Power extraction and transfer structures° RF components
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MAIN LINAC – TWO-BEAM MODULE
CLIC at 500 GeV (4248 modules)26312 Accelerating structures13156 PETS~ 70000 RF components
CLIC at 3 TeV (20924 modules)142812 Accelerating structures71406 PETS~ 400000 RF components
A. Samoshkin
(POWER EXTRACTION AND TRANSFER SYSTEM)
MAIN BEAM
DRIVE BEAM
Up to 8 accelerating structures and 4 PETS in a two-beam module
Prototype modules (20) 2016Few 100’s RF structures and components
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RF STRUCTURES AND COMPONENTS
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TD18#3 at SLAC
TD18#2 at KEK
TD24#2 at CERN (12 GHz)
PETS (12 GHz, TBTS)
PETS (11.4 GHz, test at SLAC)High-power dry load Hybrid
Variable high power splitter
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Test structures
CLIC accelerating structures
DisksCouplersCooling circuits
DisksCouplersCooling circuits [~400 W average per structure]Vacuum manifolds (10-9 mbar)Damping materialSuperstructures (2 to 4)
ACCELERATING STRUCTURES
L ~300 mm
L = 500 mm
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ENGINEERING DESIGN ISSUES (WAVEGUIDE DAMPED AS)
Iris
12WDSDVG1.8_R05
0.005 A B
Geometrical tolerance of this zone
// 0.002 A
0.001
PREP
ARE
D B
Y A
. SO
LOD
KO
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CLIC’s needs: shape accuracy ± 2.5 µmroughness Ra 25 nm
S. ATIEH
WHY WE NEED ULTRA-PRECISION MACHINING
Accelerating structures– Milling and turning
PETS– Milling
Diamond tool is required (about 7 tools per disks)
- Dimensional stability
- Maintenance of tolerances
- Less stresses
- Chips do not adhere to surface
- Expensive → well characterised
At this level of tolerances: material stress-relief annealing is mandatory → Soft material → • Special care clamping without damage• Special requirements on 3D metrology (tactile): no indents!!
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TYPICAL PROCEDURE OF UHP DISKMACHINING
Pre-Fabrication:Pre-turning + x100 μmPre-milling + x100 μmTuning holesStress relief ~180 °C (optional)Finish turning + x10μmFinish milling + x10μmStress relief ~245 °C
UHP-Machining:Mounting of vacuum clamping adapterUHP-turning of the support (diamond tools)AlignmentUHP-turning ref. plan A AlignmentUHP-turning opposite sideWave guide UHP millingIris final turning (requested up to the nose)
S. ATIEH
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DETUNED DAMPED DISK FROM VDL (TD24)
Zeiss CMM, free state measurement
• Shape accuracy 5 µm 2.6 µm achieved
• Roughness Ra 0.025Iris region achieved Ra 0.016
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ASSEMBLY PROCEDURE
Diamond machining (sealed structures)
H2 diffusion bonding/brazing at
~ 1000 ˚C
Surface treatment -cleaning with light etch
Vacuum baking650 ˚C > 10 days
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ALIGNMENT AND BONDING Reference on the external diameter: - tolerance on external diameter: 12.5 µm- tolerance on the ref. line: 1 µmAlignment done on a V-shape vertical support in granite (accuracy of 1.5 µm)
Operation done under laminar flow
Straightness measurementT24: 3.5 µm
Individual inspection
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DIFFUSION BONDING PARAMETERS AND CYCLE
Temperature: up to 1040 ˚CPressure: 0.28 MPaHolding time: 2 h
Nominal diffusion bonding cycle (under 25 mbar H2)
New infrastructure to guarantee uniform load
Straightness measurement after diffusion bonding: variation of 1 µm before and after bonding
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MACHINING AND DIFFUSION BONDING ISSUES
MILLINGTURNING
GRAINS CROSSING THE JOINING PLANE
VACUUM
DIFFUSION BONDING (H2 better surface)
MACHINING (as much turning as possible!)
H2 (no faceting!)
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1. Diffusion bonding of highprecision disk stack
2. Brazing of the manifolds by means of Gold-electroplating (validation tests needed)
3. Brazing of cooling fitting adapters
RF INTERFACE FLANGE
COOLING FITTING ADAPTER
MANIFOLD BODY
WFM WAVEGUIDE
WAVEGUIDE
ACCELERATINGSTRUCTURE
GOLD-ELECTROPLATING
ASSEMBLY OF ACCELERATING STRUCTURES (1/2)
D. GUDKOV, A. SOLODKO
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4. Brazing of prepared acceleratingstructure stack (superstructure)
5. Installation of damping material6. Welding (EBW) of manifold covers
ASSEMBLY OF ACCELERATING STRUCTURES (2/2)
D. GUDKOV , A. SOLODKO
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FABRICATION OF PETS AT 11.4 GHz
PETS for feasibility demonstration- successfully tested at SLAC
Coupler
Minitank with bars inside
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PETS OCTANT FOR TEST BEAM LINE
• Shape accuracy 4.8 µm (15 µm nominal)
• Roughness Ra 120 -180 nm(100 nm nominal)
KERN Micro- und Feinwerktechnik GmbH (DE)
L = 800 mm
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RF COMPONENTSCurrent needs for CERN and several collaborators
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HIGH POWER DRY LOADS
Internal shape
Broadband: 11.4 GHz and 12 GHz (design made by CERN)
Ferritic stainless steel SS430ripple shape tolerance = 0.01 mmflatness accuracy 0.01 mmripple shape roughness Ra 0.4.
RF measurements-28.5 dB 11.424 GHz -36.3 dB 11.994 GHzDesign (HFSS): -39.5 dB 11.424 GHz
-30.7 db 11.992 GHz
Successfully tested at high power at KEK
L ~ 0.8 m
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HIGH POWER COMPACT DRY LOADS
Water cooled load
Ceramic (SiC) - 3 mm Cu coating needed
Cu OFE body brazed to the RF flanges and to SiC inner part
L ~ 0.3 m
V. SOLDATOV
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OTHER RF COMPONENTS
Hybrids Splitter RF flanges and waveguides
Directional couplers
Phase shifter
Variable Power AttenuatorDesign made by the company
Design made by CERN
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CLIC TENTATIVE SCHEDULE
Final CLIC CDR andproposal next phase
@ CERN Council
European Strategyfor Particle Physics
@ CERN Council
Project Implementation Plan (PIP) andproposal for next phase
Draft ConceptualDesign Report (CDR)
2010 2011 2012 2013 2014 2015 2016 2017 2018
Feasibility issues (Accelerator&Detector) Conceptual design & preliminary cost estimationEngineering, industrialisation & cost optimisation ?Project Preparation Project Implementation ?
JP. Delahaye
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• Future needs for RF structures and RF components are increasing:– Conceptual design phase will be followed by a technical design phase
from 2011 to 2016 (project preparation)
• Production of RF accelerating structures and PETS is very challenging: for future CLIC structures all technical systems will have to be integrated
• Micro-precision tolerances imply dedicated machining and assembly procedures: qualification of firms for fully equipped RF structures and components is mandatory
• Industrialization studies need to be conducted with companies
CONCLUSIONS
