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