G Riddone 02022010 1 Content Introduction to RF structures and components Fabrication baseline procedure for accelerating structures Application to CERN ac structure fabrication Fabrication of PETS ID: 781232
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Slide1
5th CLIC-ACE Structure production in laboratories and in industry
G. Riddone, 02/02/2010
1
Slide2ContentIntroduction to RF structures and components
Fabrication baseline procedure for accelerating structures Application to CERN ac. structure fabrication
Fabrication of PETS
Production capability
Master schedulePresent structures (CERN, KEK, SLAC, Elettra, PSI)Towards CLIC structures (CDR, TDR)
G. Riddone, 5th CLIC-ACE, 02/02/2010
2
Slide3Introduction G. Riddone, 5th CLIC-ACE, 02/02/2010
3
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
Slide4Fabrication of accelerating structuresG. Riddone, 5th CLIC-ACE, 02/02/2010
4
Three T18 structures tested at SLAC/KEK
showed excellent test results
consequent validation of
design, machining and assembly procedure
NLC/JLC fabrication technology: validated to
100 MV/m (baseline for future CERN X-band accelerating structures)
Slide5Baseline procedureG. Riddone, 5th CLIC-ACE, 02/02/2010
5
Diamond machining (sealed structures)
H2 diffusion bonding/brazing at ~ 1000 ˚C
Cleaning with light etch
Vacuum baking
650 ˚C > 10 days
J.
Wuang
J.
Wuang
Slide6Application to CERN accelerating structuresCERN previous assembly procedure was based on vacuum brazing at 800 ˚C several changes were needed to get towards the baseline procedure
Following the post-mortem analysis of the two CERN accelerating structures T18 and T24, contamination (C, Ca) resulted to be the main problem
cleanliness had to be seriously improved
G. Riddone, 5th CLIC-ACE, 02/02/2010
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Slide7Application to CERN accelerating structures - procedure
High precision diamond machining
Cleaning
(light etch)
Brazing of coupler bodies, cooling circuits, tuning studs
(
AuCu
, 1020 °C)
Packaging and shipping
Brazing of couplers
(H
2
, 1045 °C,
AuCu
)
Machining of couplers
Diffusion bonding of disk stack
(H
2
, 1020 °C)
RF check and tuning
Baking
(vacuum,
650 °C, >10 d)
QC
G. Riddone, 5th CLIC-ACE, 02/02/2010
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Slide8Inspections G. Riddone, 5th CLIC-ACE, 02/02/2010
8
Microscopic inspection of disks before and after cleaning (on
witness pieces
)
Video inspections, SEM and microscopic inspections
Microscopic inspections before and after each relevant fabrication step
T18 KEK/SLAC design
Slide9Manufacturing at VDL
All dimensional checks are conform
Shape tolerance
±2.5
m
m
Damped disk at 12 GHz
9
G. Riddone, 5th CLIC-ACE, 02/02/2010
New
CMM (
Coordinate Measuring
Machine)
under procurement
at CERN
Slide10Cleaning G. Riddone, 5th CLIC-ACE, 02/02/2010
10
SLAC cleaning procedure as a baseline
For
degreasing
Trichloroethane
at SLAC
replaced by
Perchloroethylene
CERN procedure:
(Firm AVANTEC Performance Chemicals):
- TOPKLEAN MC 20A
- PROMOSOLV 71IPA
Tool for holding the disks
Etching
J.
Wuang
Slide11Diffusion bonding
G. Riddone, 5th CLIC-ACE, 02/02/2010
11
1045 °C, 2 h
couplers
Couplers + disks
1020 °C, 1.5 h
TD24
TD24
T18KS
Disks
Bonding at CERN: few mbar H2 partial pressure (difference with SLAC): we are actively looking for a furnace at 1 bar H
2
in Europe.
Slide12AssemblyG. Riddone, 5th CLIC-ACE, 02/02/2010
12
Assembly made on V-blocks
Verification of the assembly (before and after bonding) with a new measurement column: straightness and tilt
Straightness measurement
±2
m
m
Accelerating structure TD24 after diffusion bonding under H2
Large grain size!
13
G. Riddone, 5th CLIC-ACE, 02/02/2010
Slide14Vacuum bakingG. Riddone, 5th CLIC-ACE, 02/02/2010
14
J.
Wuang
1
st
baking: TD24 for CLEX,
two-beam test stand
CERN furnace
s
everal mechanical adaptations were needed
10
-9
mbar
Slide15RF check and tuningG. Riddone, 5th CLIC-ACE, 02/02/2010
15
Bead pulling at
11.421GHz (old test-set-up)
Before shipping RF check and tuning
were done
and results
were
good
T24#1
New test set-up is under procurement for RF measurements
Slide16Clean roomG. Riddone, 5th CLIC-ACE, 02/02/2010
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Clean room layout
Boxes under N2
Clean pieces
After the failure of CERN ac. structures, it was clear that a clean room was indispensable
Sealed bag under N2
VESTIBULE
Slide17Fabrication of PETS at 11.4 GHz
with damping material
G. Riddone, 5th CLIC-ACE, 02/02/2010
17
Bar length ~ 300 mm
Shape tolerance within specification:
± 7.5
m
m
PETS for feasibility
demonstration
under assembly
to be tested at SLAC
Damping material
Coupler
Minitank
with bars inside
Slide18Fabrication flow for PETS (11,4 GHz)
G. Riddone, 5th CLIC-ACE, 02/02/2010
18
Procedure as close as possible to the baseline, but some difference due to design and infrastructures
Cleaning
(NGL+solvent)
EB welding of the bars
QC
PETS bars
Baking
(vacuum,
200 C, 2 h)
Assembly of the
8 bars
Vacuum test
EB welding of the bars
Packaging (N2)
RF check
Shipping to SLAC
Assembly of couplers-bars and mini-tank
EB welding of tank
Final bake-out (150 C, 2h)
RF check
FINAL ASSEMBLY
Slide19Fabrication of TBL PETSG. Riddone, 5th CLIC-ACE, 02/02/2010
19
Prototype made by CIEMAT using conventional UHV best practice for cleaning and
handling
Coupler is brazed, no heat treatment for PETS itself
The CERN production will be assembled in a clean
room,
The coupler will be vacuum brazed at CERN
Status: parts fabrication, assembly should start in April
S. Doebert
Slide20Production capabilityG. Riddone, 5th CLIC-ACE, 02/02/2010
20
3
laboratories:
- ac. structures
SLAC, KEK and CERN
- PETS
CERN
5 qualified vendors for ac. structures: 2 (CERN), 2 (KEK), 1 (SLAC)
3 qualified vendors for PETS
For each structure, at least two units are manufactured
For KEK, SLAC made structure, the assembly/baking is made at SLAC
- e.g. baking of two structures in parallel
At present, potential capability up to 20. structures per year
Slide21Present structures: CERN, KEK, SLAC (base and fundamental program)G. Riddone, 5th CLIC-ACE, 02/02/2010
21
CD10
TD24
Slide22Present structures: CERN(base program)G. Riddone, 5th CLIC-ACE, 02/02/2010
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1 ac. structure (
CLEX, TBTS)
2 ac. structures with
wakefield
monitors
(
CLEX, TBTS)
Slide23Other structures
G. Riddone, 5th CLIC-ACE, 02/02/2010
23
Important involvement of other laboratories to exchange experience and to increase the market
900-mm
long structures for PSI (X-FEL) and
Elettra
(
Sincrotone
Trieste) with
wakefield
monitors
72 cells
Wakefield monitor design
Structure assembly
Slide24Master scheduleG. Riddone, 5th CLIC-ACE, 02/02/2010
24
Slide25Comparison to Jan 2009 schedule For production overall delay of about 4 months, although not on critical pathCERN structures: break of few weeks before decision to adopt baseline procedure
Several steps of baseline procedure were new for CERN: process qualification needed before application to a real structureBaseline procedure takes longer than the previous based on vacuum brazing at 800 °C
Qualification of new vendors: several trials before
achieving disks within specification
G. Riddone, 5th CLIC-ACE, 02/02/2010
25
Slide26Towards CLIC structures CDRAccelerating structure with all features: damping material and technical systems: under eng. design (first structure at the end of 2010). Assembly test with a prototype structure are scheduled in the coming weeks.
PETS with on-off system: under design. On-off system to be tested in Q3, 2010Cost estimate in needed by 2010: launched dedicated studies with three companies/institutes
G. Riddone, 5th CLIC-ACE, 02/02/2010
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Wakefield monitor
Damping material
Coupler
On-off system
AS
PETS
Slide27T4
T1
T0
Towards CLIC structures
From CDR to TDR
Main linac prototype modules
(
3 by end
of 2012
) will be built to validate the technical systems in an integrated approach
.
G. Riddone, 5th CLIC-ACE, 02/02/2010
27
These modules will contain
accelerating
structures and PETS with all required
features
Industrialization
and mass production development in collaboration with companies
Slide28ConclusionsG. Riddone, 5th CLIC-ACE, 02/02/201028
NLC/JLC fabrication technology validated for CLIC accelerating structures to 100 MV/m
CERN is implementing NLC/JLC procedures (still in learning process
)
Cleaning (etching)Diffusion bonding at ~1040 °C (H2)Vacuum baking Production capability up to 20 structures per year
higher than available testing slotsInvolvement of other laboratories to exchange experience and expertise CLIC structures with all features under design: first unit ready by end of this year
Main
linac
prototype modules for CLEX will include CLIC several structures
Industrialization, mass production and cost study launched for few
structure
configurations
Slide29SPAREG. Riddone, 5th CLIC-ACE, 02/02/2010
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Slide30G. Riddone, 5th CLIC-ACE, 02/02/201030
Assembly of accelerating structures
T24
T18 and before
Slide31Comparison SLAC/CERN31
G. Riddone, 5th CLIC-ACE, 02/02/2010
Slide32Summary of comparisonG. Riddone, 5th CLIC-ACE, 02/02/2010
32
SLAC/KEK
Fermilab
CERN old
CERN new (SLAC/KEK
based)
Diamond machining
√
√
√
√
Etch
√
√
√
√
1000 ˚C pre-fire
√
(
Ar
)
~ 100
0
˚C diffusion bonding
√
√
~
1000 ˚C brazing
√
~ 800 ˚C brazing
√
(
Ar
, Au/Cu)
√
(Vacuum, Ag/Cu)
√
Vacuum baking
√
√
√
Tank/sealed
SEALED
SEALED
SEALED
TANK
/SEALED
Slide33QUADRANTS - HDS
thick qualification part according to CLIAAS300062 - KERN
(DE)
Achieved shape accuracy ± 2.1 µm
Roughness Ra = 86 nm – 30 nm according to ISO 97
Achieved shape accuracy ± 1.3 µm
S. Atieh
G. Riddone, 5th CLIC-ACE, 02/02/2010
33
Slide34Origins translation: X 16 µm and Z -8 µm
Shape accuracy is respected ± 2.5 µm
QUADRANTS - HDS
thick qualification part according to
CLIAAS300062 –
DMP (SP)
G. Riddone, 5th CLIC-ACE, 02/02/2010
34
S. Atieh
Slide3535
35
T18 CERN - Inspection
on iris 12
Contamination between brazing and testing
35
GR, BE/RF, 19.06.2009
C
C
Ca