5 th CLIC-ACE Structure production in laboratories and industries

5th CLIC-ACE

Structure production in laboratories and industries

G. Riddone, 02/02/2010

(contribution from KEK/SLAC colleagues)

1

2

Content

• Introduction to RF structures and components

• Fabrication baseline procedure for accelerating structures

• Application to CERN accelerating structure fabrication

• Fabrication of PETS

• RF structure production capability

• RF structure master schedule

• Present structures (CERN, KEK, SLAC, Elettra, PSI)

• Towards CLIC structures (CDR, TDR)

G. Riddone, 5th CLIC-ACE, 02/02/2010

Introduction

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

4

Fabrication of accelerating structures


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)

Baseline procedure


Diamond machining (sealed

structures)

H2 diffusion bonding/brazing at

~ 1000 ˚C

Cleaning with light etch

Vacuum baking650 ˚C > 10 days

J. Wuang

J. Wuang

Application to CERN accelerating structures

• CERN previous assembly procedure was based on vacuum brazing at 800 ˚C several changes were needed for implementing 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


7

Baseline manufacturing flow

High precision diamond machining

Cleaning (light etch)

Brazing of coupler bodies, cooling

circuits, tuning studs(AuCu, 1020 °C)

Packaging and shipping

Brazing of couplers (H2, 1045 °C, AuCu)

Machining of couplers

Diffusion bonding of disk stack

(H2, 1020 °C)RF check and tuning

Baking (vacuum,

650 °C, >10 d)

QC


New for CERN

8

Inspections


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

9

Machining at VDL

All dim

ensional checks

are conform

Shape tolerance ±2.5

mmDamped disk at

12 GHz


New CMM (Coordinate Measuring Machine) under procurement at CERN

10

Cleaning


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

11

Diffusion bonding


1045 °C, 2 hcouplers

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 H2 in Europe.

12

Accelerating structure TD24 after diffusion bonding under H2

Large grain size!


13

Assembly


Assembly made on V-blocksVerification of the assembly (before and after bonding) with a new measurement column: straightness and tilt

Straightness

measurement ±2 mm

At SLAC

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RF check and tuning


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

15

Vacuum baking


acel Serial vb732 on Station 4 on 10-JUN-08

1.00E-10

1.00E-09

1.00E-08

1.00E-07

1.00E-06

1.00E-05

1.00E-04

0.75 1.75 2.80 3.73 4.76 5.81 6.85 7.89 8.93 9.97 11.01 12.06 13.10 14.14 15.18 16.22 17.26 18.23 19.27

Days on Station

To

rr

tubePres

acel Serial vb732 on Station 4 on 10-JUN-08

0

100

200

300

400

500

600

700

0.75 1.75 2.80 3.73 4.76 5.81 6.85 7.89 8.93 9.97 11.01 12.06 13.10 14.14 15.18 16.22 17.26 18.23 19.27

Days on Station

De

gre

es

C

Avg.Temp

J. Wuang

1st baking: TD24 for CLEX,two-beam test stand

CERN furnace several mechanical adaptations were needed

10-9 mbar

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VESTIBULE CLEAN ROOM with AIR CONDITIONING

Clean room


Clean room layout

Boxes under N2

Clean pieces

- After the failure of CERN ac. structures, it became clear that a clean room was indispensable

- Audits for relevant steps organized

Sealed bag under N2

RF measurement

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Fabrication of PETS at 11.4 GHz with damping material


Bar length ~ 300 mmShape tolerance within specification: ± 7.5 mm

PETS for feasibility demonstration- under assembly - to be tested at SLAC

Damping material

Coupler

Minitank with bars inside

Fabrication flow for PETS (11,4 GHz)


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

bar

s

Baking (vacuum, 200 C, 2 h)

Assembly of the 8 bars

Vacuum testEB 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

FIN

AL A

SSEM

BLY

Fabrication of TBL PETS


Prototype made by CIEMAT using conventional UHV best practice for cleaning and handlingCoupler 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

Production capability


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 PETSFor each structure, at least two units per lab. are manufactured (almost in parallel)For KEK/SLAC made structure, the assembly/baking is made at SLAC

- e.g. baking of two structures in parallelAt present, potential capability up to 20. structures per year

RF m

eas.

Baki

ng

1 wk1 wk

Total: 19 wks (about 5 months) Total: 18 wks (about 4.5 months)

10 wks

Assembly (EB welding )

6 wks

PRODUCTION CYCLE (ac. structures) PRODUCTION CYCLE (PETS @ 11.4 GHz)

ManufacturingManufacturing Baking

Tuni

ngAssembly (bonding)

4 wks 2 wks 3 wks10 wks

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Present structures: CERN, KEK, SLAC (base and fundamental program)


CD10

TD24

under eng. designunder fabricationunder assemblyready for assemblyready for testing

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Present structures: CERN(base program)


under eng. design

under fabrication

under assembly

ready for assembly

1 ac. structure (CLEX, TBTS)

2 ac. structures with wakefield monitors (CLEX, TBTS)

TBTS: two beam test standSATS: stand-alone test stand

Master schedule

G. Riddone, 5th CLIC-ACE, 02/02/2010 23Monthly revised during the KEK-SLAC-CERN collaboration WebEX meetingsLast revision:” 28.01.2010

Comparison to Jan 2009 schedule

• For production overall delay of about 4 months, although not on critical path• Priorities change as a function of test results• CERN 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 structure

• Baseline procedure takes longer than the previous based on vacuum brazing at 800 °C

• Qualification of new vendors: several trials before achieving disks within specification


Other structures


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

Towards CLIC structures • CDR

• Accelerating structure with all features: damping material, wakefield monitor 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, 2010

• Cost estimate in needed by 2010: launched dedicated studies with three companies/institutes


Wakefield monitor

Damping material

Coupler

On-off system

AS

PETS

T4

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.


• These modules will contain accelerating structures and PETS with all required features

• Industrialization and mass production development in collaboration with companies

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Conclusions


• 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 slots

• Involvement 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

SPARE


30G. Riddone, 5th CLIC-ACE, 02/02/2010

Assembly of accelerating structures

T24T18 and before

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Comparison SLAC/CERN


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Summary of comparison


SLAC/KEK Fermilab CERN oldCERN new

(SLAC/KEK based)

Diamond machining √ √ √ √

Etch √ √ √ √

1000 ˚C pre-fire √ (Ar)

~ 1000 ˚C diffusion bonding

√ √

~ 1000 ˚C brazing √

~ 800 ˚C brazing √ (Ar, Au/Cu) √ (Vacuum, Ag/Cu) √Vacuum baking √ √ √Tank/sealed SEALED SEALED SEALED TANK/SEALED

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QUADRANTS - HDS thick qualification part according to CLIAAS300062 - KERN

(DE)

Achieved shape accuracy ± 2.1 µmRoughness Ra = 86 nm – 30 nm according to ISO 97

Achieved shape accuracy ± 1.3 µm

S. Atieh


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Origins translation: X 16 µm and Z -8 µmShape accuracy is respected ± 2.5 µm

QUADRANTS - HDS thick qualification part according to CLIAAS300062 – DMP

(SP)


S. Atieh

3535

T18 CERN - Inspection on iris 12

0 2 4 6 8 10Energy (keV)

0

10

20

30

cps

C

CuCu

Cu Cu

0 2 4 6 8 10Energy (keV)

0

5

10

15

20

25

cps

C

Ca

O

CuCu

Ca

Ca

Cu Cu

0 2 4 6 8 10Energy (keV)

0

10

20

30

cps

C

Cu

CuCu

Cu

0 2 4 6 8 10Energy (keV)

0

10

20

30

cps

Cu

Cu

Cu

Cu

Contamination between brazing and testing

35GR, BE/RF, 19.06.2009

C

C

Ca

T24#1 – CERN


Documents

5 th CLIC-ACE Structure production in laboratories and industries