PRE-ALIGNMENT for CDR

CTC meeting

Hélène MAINAUD DURAND, BE/ABP/SU, 06/04/2010

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Determination of the position of the components Review of the possible solutionsStrategy towards the feasibility

General concept of re-positioningBaseline Strategy towards the feasibility

Special case of the Final Focus

ConclusionProposed pre-alignment solution for CDRStudies for the TDR

OutlinePre-alignment

Determination of the position of the components in a general

coordinate system

Repositioning

= +

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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)

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Status of the different solutions

Metrologic Reference Network (MRN)

Support Pre-alignment Network (SPN)

Alignment and fiducialisation of each component on the supports (AFC)

• Stretched wire, modelized in vertical with HLS system• Long range RASCLIC (NIKHEF)• Multi-point alignment system based on laser beam.

No solution answering the requirements exists yet!

• Stretched wire• RASNIK, short range RASCLIC (NIKHEF)• Multi-point alignment system based on laser beam.

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Status of the different solutions

Pre-alignment solutions from NIKHEF

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

RASCLIC RASNIK

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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

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Status of the different solutions Stretched wire solution

• Concept of MRN to be validated in the TT1 facility

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Status of the different solutions Stretched wire solution

• Two types of WPS

cWPS oWPS

Technology Capacitive Optical

Accuracy (μm) 7 10

Repeatability (μm) 1 7

Precision (μm) 1 7

Acq. Frequency (Hz) 100 0.1

Resistance to radiation 200 kGy (sensor)500 Gy (remote electronics)

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Wire Carbone peek Vectran

Sag (mm) for 200 m 76.5 mm 45.5 mm

Cost 5000 CHF 500 $

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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 nowcWPS:

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 wireDevelopment of a concept allowing to stretch a wire without access to the sensors and the wire protectionA 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 frequencyDetermination of the local deviation of vertical (so to have a perfect knowledge of the geoïd)

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Repositioning Baseline

MB Quad DB and MB girders

Hypotheses

Solution

Issues

•Motorized displacements along 5 DOF• Range ± 3 mm• Resolution: 0.5 micron

•Motorized displacements along 3 DOF• Range ± 3 mm• Resolution < 0.5 micron

Cam movers CTF2 concept, with linear actuators

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

Repositioning Strategy

MB Quad // cam movers

DB and MB girders // linear actuators

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 of a SLS type cam mover (1 DOF mock-up)

Validation of on a 5 DOF mock-up

Validation on the two beam module prototype

DR approved by the finance commitee Market Survey to be prepared and sent

Validation on a pre-alignment mock-up

Validation on the two beam module prototype

Re-installation of CTF2 repositioning solution

Cost for 5 cam movers (one support): 52.5 kCHF

Cost for 3 linear actuators (one girder): 42 kCHF

Case of the final focus

Determination of the position of QD0 w.r.t other components of the BDS (500 last meters)

stretched wire + WPS. (stretched wire 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 QD0 w.r.t the other: Solution based on RASNIK system, through the detectors (using dead space between detector areas)

Remaining issues: Perform simulations to find the best configuration Validate the proposed solution

Repositioning solution: cam movers for 5 DOF

Remaining issue: Integration

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

Summary: alternative studies for TDR

Determination of the position of the components: In collaboration with NIKHEF (definition of the WP under progress):o Design of a short range / long range solution adapted for CLIC

requirementso Integration of the short range solution on the two beam module

prototypeo Inter-comparison of the long range solution in TT1 / TZ32 tunnels

Validation of the concept of the multi-point laser based solutionRepositioning:

Validation of the concept of articulation point with cam movers