1. Structure stacking alignment tolerances CLIC Workshop 2015 26-30 January 2015 CERN Anastasiya Solodko, on behalf of the CLIC study team

2. Requirements 27/01/2015 2 Emittance preservation Requirements from luminosity N. Catalan Lasheras “Structure review follow-up”

3. Test structures 3 T18 (TD18) T24 TD24 TD24 SiC TD26 CLEX TD26 CC TDxx CC next structures… A. Olyunin A. Samoshkin 27/01/2015

4. #ParameterValue, mm 1Iris shape0.005 2Face plane position0.002 3Face plane perpendicularity 0.002 4Outer diameter80±0.002 5Flatness, face A0.001 6Flatness, face t+g from A0.001 Disc parameters Tolerances of individual disc 4 27/01/2015

5. Assembly of the disc stack 5 Assembly process Straightness measurements before and after bonding Pressure application for bonding Alignment measurements before and after bonding -discs dimensional control at factory (shape accuracy, flatness and Ra) -Final dimensional control at CERN -Alignment on dedicated V-shaped column -Verification of the assembly (before and after bonding) with a measurement column: straightness and tilt. 0.002 Pressure  0.1 MPa P= F/S 27/01/2015

6. Alignment tooling Column Mitutoyo 600mm (1.1 + 0.6L µm) Camera Vision Equipment for: -measurement of external diameter of discs; -straightness measurement of disc stacks; -angular positioning of discs using a reference line. Comparator (±0.5 µm) with gage blocks 0.002 V-shaped column 27/01/2015 6

7. Environment (since 2012)  Assembly of the structures is done in air-conditioned room with air-filtering which corresponds to a «salle blanche».  The room is equipped with leak detector of H 2 and of N 2 27/01/2015 7

8. Clamping during measurement -Flatness measurement on both sides of the disc; -Measurement of the iris profile in four sections; -Measurement of four “nose” profiles. Tolerances of individual disc 8 27/01/2015 Flatness Iris profile “Nose” profile

9. Straightness measurements before and after bonding 9 Before bondingAfter bonding Measurements can be done for six or more generatrix. Measurements can be done for one/two generatrix due to: -position of the structure in the v-shape column; -position of the bonding/alignment tools; -position of damping waveguides; -position of engraved numbers. 27/01/2015

10. The beam axis deviation of the accelerating structure can be considered as accumulated deviation of different parameters of each individual disc in assembly. Possible imperfection during assembly 1. Bowing due to faces orientation 2. Disc-to-disc transverse misalignment Bowing due to disc slips 3. Bookshelving errors Avoided errors thanks to the use of the vertical V-shaped column: Tolerances of assembly 10 27/01/2015

11. Disc-to-disc transverse misalignment can be calculated as a difference between two discs having for outer diameter MMC * and LMC *. The deviation X - axis deviation in case the MMC disc and Y - in case the LMC disc, both are in contact with V-shaped support. The resulting “light-blue” cylinder diameter is the MAX axis deviation. V-shaped support X Y (calculated from tolerances) Resulting (MAX) cylinder Ø 2xY mm ~ 3µm * Maximum and Least Material Condition Tolerances of assembly 11 27/01/2015

12. Old bonding tooling 12 EDMS #1078997 Straightness measurements before/after bonding 27/01/2015 -T18 N1; -Ø45 mm. Assembly in V-shaped column Pressure application January 2010 New bonding tooling – in October 2010

13. Old bonding tooling. Transportation to the oven 13 Straightness measurements before/after transportation -T18 N2; -Ø45 mm. EDMS #1058936 Transport of accelerating structure in its cover Accelerating structure in laminar flow Accelerating structure after transport January 2010 27/01/2015 New bonding tooling – in October 2010

14. Results (TD26 CLEX N5) 14 External diameter measurements Difference between min and max values is 5 µm Straightness measurement before bonding 27/01/2015 Pressure application for bonding Pressure  0.1 MPa P= F/S NEW

15. 15 Straightness measurement after bonding 27/01/2015 Results (TD26 CLEX N5)

16. 16 Diameter deviation 27/01/2015 Results (TD26 CLEX N5)

17. Alignment data 17 Eleni Zisopoulou 27/01/2015 Old bonding tooling

18. Conclusion and actions 27/01/2015 18 1. Change of the tooling resulted in better tolerances before/after bonding; 2. Before bonding measurements can be done for two generatrix because of the position of the structure in the v-shape column, the position of the tooling and the position of engraved numbers; 3. After bonding measurements can be done for six generatrix; 4. New bonding tooling will be designed which will allow: A. to measure more generatrix before bonding; B. to use a small oven (the oven is integrated in assembly room see slide N7); 5. More systematic measurements have to be done: A. Several generatrix; B. The same place (before and after bonding); C. Data: straightness profile, straightness value etc. have to be properly analysed and stored; 6. Possibility to use a new more modern column for straightness measurement.

19. 27/01/2015 19 Many thanks to Serge for his precise and excellent work! Thank you for your attention!