10/2007 M.Taborelli, TS-MME

Structure Manufacturing, Achievements and Challenges

M.Taborelli

-Technology-Shape accuracy-Surface quality-Assembly accuracy

Contributions of : G.Arnau-Izquierdo, A.Cherif, D.Glaude, R.Leuxe, J.Huopana, S.Mathot, CLIC study team

10/2007 M.Taborelli, TS-MME

Copper, disc structures

- Machining by diamond turning: shape accuracy of 2-3m in the iris region

-alignment of the discs on V-shaped marble before assembly in a stack: use external disc surface as reference.

-assembly by vacuum brazing (T up to 820C) or by bolting- no rf-damping by design

disc structures

10/2007 M.Taborelli, TS-MME

Ra = 0.05 m

disc structures

30 GHz copper structures: surface quality

Recrystallization after thermal treatment (vacuum brazing cycle at 820 C)

10/2007 M.Taborelli, TS-MME

Achieved accuracy for brazing assembly of disc structures: better than 5 µm

Bookshelfing: assembly on aslopeV-bench gives “tilted” discs

Smaller and random error: assembly on vertical V-bench, as a tower

5 μ

m

The type of error depends on the assembly procedure

disc structures

10/2007 M.Taborelli, TS-MME

Copper quadrant structures: example 30GHz

-machining by 3D milling: carbide tools or single crystal diamond tools

-alignment of the quadrants still under study

-assembly by bolting

-rf-damping implemented in the design

-target accuracy: 1 μm on shape!!!

quadrant structures

160 mm

53 mm

10/2007 M.Taborelli, TS-MME

Present specifications: 5 m shape tolerance (…..the best that can be done)

Accuracy: quadrant structures

10/2007 M.Taborelli, TS-MME

11.4 GHz Vg1 structure in production (11WDSQVg1)

300 mm

10/2007 M.Taborelli, TS-MME

Surface quality

Ra=0.02-0.2Ra= 0.2-0.4

Diamond millingConventional tools milling

1 mm 1 mm

0.01 mm 0.01 mm

quadrant structures

10/2007 M.Taborelli, TS-MME

Solvent cleaned

Vacuum baked 750C x 1h

Effect of thermal treatment

quadrant structures

Milled surface(carbide tools)

10 µm

10 µm

10/2007 M.Taborelli, TS-MME

Metrology on copper quadrants

Measurement: coordinate measuring machine, contact with 0.1N force, accuracy +/-3 µm (at CERN), scan pt. by pt. on the surface ………in parallel with RF low power control

quadrant structures

-4.5

-4

-3.5

-3

-2.5

-2

-1.5

21 22 23 24 25 26 27 28

[mm]

Zmeas

Znom

zerr10

Circular-thick

-4.5

-4

-3.5

-3

-2.5

-2

-1.5

17 18 19 20 21 22 23 24

[mm]

[mm

]

Zmeas

Znom

zerr10

HDS-thick

10/2007 M.Taborelli, TS-MME

Achieved shape accuracy, milled parts

quadrant structures

-0.035

-0.03

-0.025

-0.02

-0.015

-0.01

-0.005

0

0.005

0.01

0.015

0.02

0.025

0.03

0.035

HD

S10

HD

S60

HD

S6

HD

S11

HD

S6-

draf

t

HD

S-t

hick

Circ

-thi

ck

Circ

-thi

ck w

ave

mac

hin

ing

err

or

[mm

]

2004 2005 2006

OFE-copper

2007

meas.a

ccu

racy

**

*

10/2007 M.Taborelli, TS-MME

Alignment: “universal” test piece

-Balls and grooves (2 types, magenta and orange)-Elastic averaging shapes (green)-Pins (not shown)

-Metrology references are included

quadrant structures

10/2007 M.Taborelli, TS-MME

RF design of structures

Mech. design, fabrication, preparation

Test, analysis

CTF3 SLAC KEK

R&DMaterials,preparation

RF Model

The goal is the fabrication of 1 geometry in 4 months and 10 geometries per year; in 2007: 4 received (1 0rdered 2006) + 3 in fabrication

Production of structures