As fabricated

CLIC Structure fabrication

On behalf of the X-Band production team

Joel Sauza Bedolla

EN/MME/MA

After high gradient workshop

As designed

Summary

• Production status

• Introduction

• Structures• TD26R1CC

• TD31

• Klystron base (TD26)

• TD26 Halves

• Furnace qualification procedure

• Conclusions

2

Pro

du

ctio

n S

tatu

s

3

X-band Production at CERN

TD

26

R1

CC

Klys

tron

b

ased

TD

31

TD26

H

alve

s

RF Design Mechanical design Manufacturing Assembly Post-mortemHigh Power

N1

N2

N3

N4

N1

N2

N3

N4

N1

N2

N1

N1

Baked

Non baked

Bonding planned w 28

Couplers brazing w 25Bonding by end of July

Baked

Unbaked

Metrology after bonding ongoing

Introduction• Sensitivity analysis to find most important parameters affecting frequency changes.

• We are trying to assess assembly (diffusion boding) contribution to geometry changes.

• Frequency changes measurements before-after bonding have been performed. Complemented by mechanical measurements.

• Correlation between geometry changes against frequency changes has not been confirmed (structures T24 and TD26). However, it is suspected a change on the geometry after bonding.

4-10 -8 -6 -4 -2 0 2 4 6 8 1011.98

11.985

11.99

11.995

12

12.005

12.01

Fre

quency(G

Hz)

TD26 First Cell

nominal±10 (µm)

a

L

b

w

HW

TD26R1CC

• 26 tapered cells with integrated coupling cells. • Design changes:

• “Nose” of the waveguide from an elliptical geometry to a 4-th order polynomial function. RF Improvement

• The radius at the bottom of the RF waveguide was increased from 0.5 mm to 1 mm to allow the use of bigger milling cutter. Economic

• Disc diameter was increased from 74 mm to 83 mm. Design

5

X-band Production at CERN

TD

26

RF Design Mechanical design Manufacturing Assembly

TD26R1CC – After bonding measurements

• Identical bonding cycles (same company) on different days for N1, N2 and N3.• 1030 °C x 1.5 hr x 30 Kg (0.06 MPa)

• External diameter reduction in average 12 µm• Significant with respect to the allowed tolerances

• Observed in structures N1, N2 and N3. Double checked on structure N1.

• The total length of the structure is smaller by 25 µm

• What is happening with the internal shape?• Has it changed?

• It has been decided to cut structure N1 and to measure internal changes

6

TD26R1CC – After bonding measurements

• Measurement of iris before cutting the structure N1.

• It was possible to measure first 4 iris of each side.

• Hypothesis: bigger irises• No trend found

• There are peaks on the same position of the different irises. They may indicate dust on the tip. These particular measurements are not reliable.

7

Cutting plan

8G00G01G02G03

G14G15G16

Already performed

Preserved for interferometer measurements

TD26R1CC – After bonding measurements• Bottom of the cross flatness measurement after cutting the structure.

• First three discs: G00, G01 and G02

• Flatness error seems to be related to disc position on the structure

9

G00: 42 µmThe iris collapsed

G01: 15 µmBigger error on the waveguides

G02: 4.3 µm

As manufactured measurementG00: 2.8 µm

As manufactured measurementG01: 0.05 µm

As manufactured measurementG02: 0.03 µm

TD26R1CC – After bonding measurements• Iris measurements after cutting.

• Hypothesis: irises are bigger• The change is small. Two irises are bigger and one is smaller w.r.t. supplier

measurements

10

Nominal Supplier After cutting Supplier-Nominal After cutting-Supplier

G02-1 6,177 6,17797 6,1792 0,00097 0,00123

G01-1 6,2384 6,23728 6,2382 -0,00112 0,00092

G00-1 6,3 6,29867 6,2982 -0,00133 -0,00047

Dimensions in mm

TD26R1CC – After bonding measurements• Measurement of the nose shape.

• Datum references have changed with respect to original measurements.

• Shape is improving according to disc position. G00 is worst than G02

• Hypothesis: b parameter should be bigger.• Refuse the hypothesis

11

14 µm

G01 G02

7 µm

20 µm 16 µm

7 µm 10 µm

9 µm 13 µm

6 µm9 µm

11 µm 9 µm

G00

TD26R1CC – After bonding measurements• Measurement of the vertical nose shape.

• The shape of the noses (previous slide) was measured in the middle of the vertical.

• Is the weight excessive?

12

G00

Four sections look similar

Iris

Bottom of the cross

No

se v

erti

cal p

rofi

le

G02

Four sections look similar

G01 still not measured

12 µm20 µm

TD26R1CC – After bonding measurements• The flatness of the bottom of the cross is worsened.

• Irises have not significantly changed.

• b parameter (diameter formed by the noses) is smaller. • It has a conical shape.

• Sensitive analysis:• One parameter is changed at the time. Combined effect has not been tested.• Uniform deformation has been assumed.

• It is possible now to improve the sensitive analysis with real data.

• The cutting and measurements are going on. More data in coming weeks.

• From previous experiences, at high bonding temperature (1030 °C ) the applied weight seems irrelevant (it does not improve bonding). It seems that applying weight is deforming the cells.

• If the tendency is maintained, do these measurement can explain breakdowns happening at the input of the structure?

13

TD31R1CC

• 380 GeV baseline structure. 72 MV/m gradient.

• Similar geometry of TD26 (Ø83 mm).

• Production of 138 cells + components.

• Improvements on transport and handling of parts

14

82.996

82.997

82.998

82.999

83

83.001

83.002

83.003

83.004

G02

-1

G02

-4

G03

-3

G04

-2

G05

-1

G05

-4

G06

-3

G07

-2

G08

-1

G08

-4

G09

-3

G10

-2

G10

-5

G11

-3

G12

-2

G13

-1

G13

-4

G14

-3

G15

-2

G16

-1

G16

-4

G17

-3

G18

-2

G19

-1

G19

-4

G20

-3

G21

-1

G21

-4

G22

-3

G23

-2

G24

-1

G24

-4

G25

-3

G26

-2

G27

-1

G27

-4

G28

-3

G29

-2

G30

-1

G30

-4

mm

Production order -->

Diameter 83 mm

Diameter B Tol Up Tol Down Linear (Diameter B)

X-band Production at CERN

TD

31

RF Design Mechanical design Manufacturing

TD31R1CC

15

• Visual inspection

• Assembly planning of TD31 N1 and N2• Couplers brazing on week 25

• Bonding by the end of July

Klystron based (TD26)

• Alternative scenario for 380 GeV.

• 75 MV/m accelerating gradient.

• Tested easily and can be implemented faster than two-beam modules.

• Competitive cost at lower energy.

• From the manufacturing point of view similar to TD26 and TD31• Smaller irises• Smaller thickness• Similar tolerances

• Mechanical design completed. Tendering on 2020.

16

X-band Production at CERN

Kly

stro

n b

ased

RF Design Mechanical design

TD26 Halves• New prototype to be assembled by Electron Beam Welding.

• Heat treatments are avoided. Hard copper structure.

• There are less components and less assembly steps. Bigger risks if the halve is not manufactured accordingly.

• Tooling is complete. Developed in collaboration with Dutch company STTLS.

• Technical drawings almost complete.

17

TD26 Halves• Alignment is critical on transverse and longitudinal directions.

• The pockets are eccentric.

• The assembly tooling consists on a tray containing defined contact points.

• Incrementally add weight to compress the alignment rings

18

Furnace qualification procedure• Comparative analysis:

1. Pollution analysis of a witness disc (WD) at CERN using Automatic Particle Analysis (APA) in the Sigma-SEM.

2. Run of the CLIC nominal bonding cycle with WD and a piece of SS.

3. Pollution analysis of the WD (using APA in the SEM) and SS piece at CERN.

19

Furnace qualification procedure• Automatic Particle Analysis module of the software (Aztec) used for the

Energy Dispersive X-Ray Spectroscopy (EDS) analysis call “Features”.• Identification of particles by grey level (shape is also possible).

• How it works?• Definition of an “Area” the surface of our Witness Disc• This area is composed by “fields” the individual images needed to cover the full

disc. It is possible to cover between 70-80% of the disc

20

• Field each of the individual regions that compose the area.

• Each field will detect features in grey level.

• The image has to be characterized to determine lighter or heavier elements.

Field

Furnace qualification procedure

21

• Apart from the detection limits intrinsic to the EDS analysis, it is possible to set limits to the analysis: • Particles > 50 µm• If more than 100 features per field

• Manually it took 8h for 50 particle analysis covering 1% of the surface of the WD. Now we can analyse up to 18000 particles and 80% of the surface disc.

• However the procedure does not save time because the post treatment data is very time consuming but he reproducibility and reliability of the test is highly improved.

Furnace qualification procedure

22

Conclusions

• The post-mortem analysis of TD26-N1 is suggesting that bonding parameters (weight and high temperature) are not optimized.

• Deformation on the disc has been observed on the flatness and vertical shape of the waveguide.

• TD31 is ready for assembly.

• Klystron based structure delayed for production

• TD26 Halves: • Tooling design completed

• Mechanical drawings almost ready. We are expecting to launch production soon.

• Furnace qualification procedure: updated and improved.

23

Ready for questions

24

Thank you for your attentionNuria Catalan Lasheras

Anastasiya Solodko

Kamil Tomasz Szypula

Serge Lebet

Enrique Rodriguez Castro

Sergio Gonzalez Anton

Hikmet Bursali

Joel Sauza Bedolla