PRE-ALIGNMENT for CDR CTC meeting

1. PRE-ALIGNMENT for CDR CTC meeting Hélène MAINAUD DURAND, BE/ABP/SU, 06/04/2010

2. Determination of the position of the components in a general coordinate system Outline = Pre-alignment + Repositioning • Determination of the position of the components • Review of the possible solutions • Strategy towards the feasibility • General concept of re-positioning • Baseline • Strategy towards the feasibility • Special case of the Final Focus • Conclusion • Proposed pre-alignment solution for CDR • Studies for the TDR

3. Determination of the position of the components Geodetic Reference Network (GRN) Metrologic Reference Network (MRN) Support Pre-alignment Network (SPN) Alignment and fiducialisation of each component on the supports (AFC)

4. No solution answering the requirements exists yet! Status of the different solutions Metrologic Reference Network (MRN) • Stretched wire, modelized in vertical with HLS system • Long range RASCLIC (NIKHEF) • Multi-point alignment system based on laser beam. Support Pre-alignment Network (SPN) • Stretched wire • RASNIK, short range RASCLIC (NIKHEF) • Multi-point alignment system based on laser beam. Alignment and fiducialisation of each component on the supports (AFC)

5. Status of the different solutions Pre-alignment solutions from NIKHEF RASCLIC RASNIK • Drawbacks: • Vacuum flanges on long distances (replaced by helium flushing) • 3 point alignment system  because of non regular distances along main linac, the creation of sub-network is needed. • Not easy at all to establish a formal collaboration with NIKHEF

6. Status of the different solutions Laser Alignment Multipoint Based- Design approach (LAMBDA) • Technical note concerning the concept proposal in progress • Preliminary study concerning the mechanical shutters will start soon • Definition of the subject for a doctorate student in progress

7. Status of the different solutions Stretched wire solution • Concept of MRN to be validated in the TT1 facility

8. Status of the different solutions Stretched wire solution • Two types of WPS

9. Status of the different solutions Strategy towards the feasibility • Only one solution ready for CDR : stretched wire + WPS • It is not mandatory to define the technology concerning the WPS now • cWPS: • design of a new mechanical interface and associated calibration bench  improve the accuracy (target : accuracy < 5 μm) • cost study to be launched for 50 000 units. • oWPS: • definition of the next generation under progress • Several studies launched to address the drawbacks of the WPS and stretched wire • Development of a concept allowing to stretch a wire without access to the sensors and the wire protection • A method was found to stretch two wires in the same optical sensor (to be validated on long distance) • Test of a concept to modelize the wire measuring its frequency • Determination of the local deviation of vertical (so to have a perfect knowledge of the geoïd)

10. Repositioning Baseline MB Quad DB and MB girders Hypotheses • Motorized displacements along 5 DOF • Range ± 3 mm • Resolution: 0.5 micron • Motorized displacements along 3 DOF • Range ± 3 mm • Resolution < 0.5 micron Solution Cam movers CTF2 concept, with linear actuators Issues • No existing cam mover with the required resolution, and high 1st frequency (> 50Hz) • Repositioning algorithm • Kinematics (internal friction, clearances, transmission between girders) • Resizing needed due to higher loads • Constraints from other systems (waveguides, vacuum)  New design and validation for both solutions

11. Repositioning Strategy MB Quad // cam movers DB and MB girders // linear actuators Validation of a SLS type cam mover (1 DOF mock-up) Re-installation of CTF2 repositioning solution Validation of on a 5 DOF mock-up Validation on a pre-alignment mock-up • Design of a new cradle (MME design office) • 9 high resolution linear actuators to be ordered this week (ZTS) • 5 high resolution cam movers to be ordered this week (ZTS) Validation on the two beam module prototype Validation on the two beam module prototype • DR approved by the finance commitee • Market Survey to be prepared and sent Cost for 5 cam movers (one support): 52.5 kCHF Cost for 3 linear actuators (one girder): 42 kCHF

12. Case of the final focus • Determination of the position of QD0w.r.tother components of the BDS (500 last meters) •  stretchedwire + WPS. (stretchedwire of 500m, demonstrated in TT83) • Remaining issues: • 10 microns (rms) concerning the position of the zero of QD0 • Integration • Monitoring of the position of one QD0w.r.t the other: •  Solution based on RASNIK system, through the detectors (usingdeadspacebetween detector areas) • Remaining issues: • Perform simulations to find the best configuration • Validate the proposed solution • Repositioning solution: cammovers for 5 DOF • Remaining issue: • Integration

13. Summary: proposed solution for CDR Determination of the position of the components:  stretched wire + WPS sensors for MRN and SPN Repositioning:  MB quad: cam mover  Girders: high precision linear actuators

14. Summary: alternative studies for TDR • Determination of the position of the components: •  In collaboration with NIKHEF (definition of the WP under progress): • Design of a short range / long range solution adapted for CLIC requirements • Integration of the short range solution on the two beam module prototype • Inter-comparison of the long range solution in TT1 / TZ32 tunnels •  Validation of the concept of the multi-point laser based solution Repositioning:  Validation of the concept of articulation point with cam movers