1. H. MAINAUD DURAND on behalf of the CLIC active pre-alignement team with 3D views and data from Hubert Gerwig, Richard Rosing and Juha Kemppinen Pre-alignment status MDI meeting, 02/09/2011

2. 2 SUMMARY Monitoring of QD0 Study on cam movers on a 5 DOF setup

3. 3 Monitoring of QD0 Concept 4 Reference Rings (RR) located at each extremity of QD0, supported from outer tube 6 radial spokes per RR RR spoke Line of sight for alignment systems In two steps: A monitoring of the position of QD0 w.r.t RR thanks to proximity sensors. (initial calibration of their position performed on a CMM) A transfer of the position of RR thanks to 6 spokes to alignment systems. By combination of redundant information, the position of the center of 4 RR is computed.

4. 4 Monitoring of QD0 Concept: alignment systems RasNik RasCLIC laser + beam expander diffraction plate pixel image sensor

5. 5 Monitoring of QD0 Latest results: choice of material RR and spokes in Zerodur

6. 6 Monitoring of QD0 Latest results : design of RR RR: 6 gage blocks with flat surface, glued between the 2 rings Simulations concerning RR : deformation ~ 1 μm. As we will perform relative measurements, no impact

7. 7 Monitoring of QD0 Latest results : design of spokes Squares rods in zerodur (6 mm x 6 mm), with a length of 200 mm, glued together (final length 1 m) At the RR extremity of spoke: a hard stainless steel precision ball, pressed against the reference surface of gage block of RR (a screwing concept using torque screw is being studied. Each spoke is supported by a square aluminium pipe. Flexo, made of silicon rubber will be the link between spoke and pipe, allowing that no radial force is applied, except the load of the bar itself.

8. 8 Monitoring of QD0 Latest results : status At the « non-RR » extremity of spoke: RasCLIC and RasNik system will be tested on two beam test modules (169/S-029)

9. 9 Monitoring of QD0 Latest results : status First tests will concern the assembly of 1m of zerodur rods: guiding, then heating / thermal expansion behavior

10. 10 Monitoring of QD0 Integration

11. 11 SUMMARY Monitoring of QD0 Study on cam movers on a 5 DOF setup

12. 12 Monitoring of QD0 Why a 5 DOF mock-up to validate cam movers? In order to have a better knowledge of cam movers and algorithms of repositioning For the MB quads of Main linac and BDS, we are looking for a resolution and repeatability of adjstument never reached before (below 1 μm). These requirements are not fulfilled on other facilities where cam movers are installed (LCLS @ SLAC, SLS @ PSI). Cam movers were validated on a 1 DOF setup (where a repeatibility below 1 μm) was reached, but the setup was too rigid to measure resonant frequencies. (Target on the 5 DOF mock-up: first resonant frequency > 50 Hz, in order to be compatible with stabilization requirements).

13. 13 Monitoring of QD0 Description of 5 DOF mock-up

14. 14 Monitoring of QD0 Cam movers Configuration: 5 cam movers in order to provide 5 DOF A kinematic mount interface below the common support of MB quad support providing a unique solution of interface 4 interface with ground for higher stiffness Cam movers from SLS Upgraded SLS cam movers: (optimization of clearances and links between parts) Cam movers from ZTS vvu Kosice: A more rigid structure Higher gear ratio (Worm gearbox ratio = 60, bearing reducer ratio = 85) Different worm gear and stepper motor The stepper motor and the worm gear unit are coupled to the cam shaft via a zero backlash bearing reducer instead of a planetary gear A high resolution absolute rotary angle encoder from Renishaw is directly mounted on the cam shaft

15. 15 Monitoring of QD0 Latest results Blank assembly of the setup Resolution of displacements: According to the manufacturer, the cam mover’s movement resolution is 3.8’’. Based on this, the 5 DOF setup theoretical resolution in translations is below 1µm and in rotations below 1µrad. The cam movers were not calibrated before the blank assembly of the 5 DOF setup so the control algorithm cannot be fully exploited. Therefore it was not possible to test the resolution of re- adjustment of all translations and rotations separately. First tests do however indicate that the re-adjustment resolution of translations are below 2 µm. But area very noisy: standard deviation of WPS measurements ~ 1.3 μm. Eigenfrequencies measurements: Before concrete is added around the plates Several natural frequencies were measured below 50 Hz, coming from the mechanical plates and their anchoring screws (see edms report n°1152988 from Mechanical Measurement Lab). A RMS integrated level close to 9 nm at 1 Hz was computed; this confirmed that the area is too noisy for our measurements.

16. 16 Monitoring of QD0 Next steps Find a new area Calibration of cam movers Remounting of 5 DOF setup, with higher rigidity of mechanical plates Determination of the first resonant frequencies of the support Extrapolation at MDI case