Stabilisation WG meeting 11 21 th February 2013 CTC summary

1. Stabilisation WG meeting 1121thFebruary 2013CTC summary The research leading to these results has received funding from the European Commission under the FP7 Research Infrastructures project EuCARD

2. Objectives meeting • Meet up • Manpower & collaboration status • Review status • Final focus status • MBQ stabilisation and Nano-positioning status • Other • Milestones 2013 • Make a list of open points + determine priorities • Share work load • Decide on follow up meetings • AOB

3. Manpower + collaborationstatus

4. Final focus stabilisation CAM based alignment system Active stabilization system IP Beam based feedback 40 to 100 ton pre-isolator Frequency 1-2 Hz Cantilever 50 Hz So far no link was made between all systems (control)

5. Ongoing work FF • IP Beam based feedback • Mechanical stabilisation

6. Ongoing work FF • Precise model • Noise of sensors limits stability reached • Tests with other sensor Guralp 3ESP • + Better noise curve than Guralp 6T • More difficult transfer function • Implementation ongoing • - Size of sensor • Development sensor (patent) Prototype 1 ready and being tested Miniaturized prototype 2 end of March April: testing on active support

7. Ongoing work FF • Study of active cables to damp cantilever • (CLIC/ILC) + possibility positioning • + improves transfertfunction • + Improves stiffness against direct forces • - Implementation of cables in push pull detector Christophe showed possible control strategies and showed 3 limitations due to: Sensor tilt to horizontal coupling Flexible connections between sensor and actuator Flexible support Advice to have an intermediate soft support (20Hz)

8. Ongoing work FF S. Janssens What is needed to damp/influence peak of pre-isolator mode? Comparison several strategies Velocity feedback xp Combination x and xp feedback Issues pre-isolator: Ground motion at 1 Hz > 12 m is not coherent (LHC GM measurements), active damping and transmissibility reduction at 1 Hz is needed Compliance too high, demonstrated with small airflow Maximum 1 µrad roll allowed for luminosity Cantilever is huge lever arm, requiring even higher resolution on pre isolator actuators

9. Ongoing work FF S. Janssens PID on xp + activ stab. Possible transfer function between ground and QD0 + no drift at low freq Possibility to change Preisolator position !!!No noises or filters in it!!!!

10. Final focus stabilisation Open points: QD0 inside detector ? No decision next two years Mechanical Design pre isolator is linked to having the magnet inside the detector or not Noise model near particle detector should be studied/measured. Coherence ? For FF go from integrated RMS to integrated luminosity, model and test different solutions Make the link between the two FF and between FF and BDS and MBQ for multiple d.o.f. Choice and performance fp actuators: noise curve, force autority? Mock-up construction pre isolator: decision : Not at the moment Increase quality and number of integrated models Study existing hardware components: contact industry for existing components We need to set a clearer target for FF

11. Further Research proposal (tender/inhouse) Requires a student Research goals • 1. Make a dynamic model of the system presented. For this model: • give the transfer functions between all degrees of freedom and the ground • make a table of all the modal frequencies and their decomposition in eigenvectors • graphical representation of the evolution of the modal frequencies and their decomposition for a changing γ from 0 up to 15 degrees which changes the position of mg,mQF1, mst, mstb, mQD0. • What is the effect of increasing the 1st mode to 20 Hz? • 2. Propose the best active damping (velocity feedback, Integrated Force Feedback,…) system which: • damps the 1st mode of Mpi critically • Reduces the 1st mode from 20 Hz to 1 Hz through active control • uses existing technologies compliant with the environmental parameters, • does decrease the drop off above 2ωpi in the transfer function between wpi and xpi, for the ground vibrations specified,due to noise or any other limitations (actuator or sensors). • Specify the number actuators/sensors (The 4 specified are a suggestion). • Is it better to use a global controller or have each leg have its own SISO controller and decouple them with joints? • Simulate the performance of the proposed isolation system in an environment with ground vibrations and applying actual sensor/actuator, sensitivity, noise and resolution. ~2 months ~5 months

12. MBQ: build 3 modules “best available design” Type 1 ISR Type 1 CLEX Functional performance testing + development time: Study and try assembly Requires controlled stable environment (Temperature, Vibrations, Access) Demonstration feasibility + ultimate performance stab. + positioning Water cooling + powering magnet Test module location not adapted for this. Magneticmeasurements and fiducialisation Type 1 Test module withdummymagnet Integration in test module, connections to other modules, robust show case, transport, … Demonstration alignment and stabilization but not representative for CLIC tunnel Type 4 ISR Type 4 Test module MBQ modules upgradable (bolted together, no welds). K.Artoos, Stabilisation WG , 21th February 2013

13. Main beamquadrupolestabilisation Design and end of drafting MBQ type 1 stabilisation for ISR tests + CLEX, Testmodule:     Week 11 Fabrication type 1: 1.5 month Start assembly type 1: end of April,  Assembly 1 week Controller electronics type 1 ISR ready : end of April Testing type 1 ISR stabilisation : May + June (2 months) Assembly type 1 for test module: second week of May. Design and end drafting MBQ type 4 stabilsiation for ISR tests/test module: End of March Fabrication 1.5 month Start assembly type 4: Middle of May, assembly 1 week. Controller electronics type 4 ready: end of May Testing type 4 ISR stabilisation: June, July

14. Combine withalignment Presentation Juha

15. Sensordevelopments • LAPP sensor (for FF and MBQ) NDA with CERN • ULB sensor • CERN “reversed engineering” sensors • Out sourcing vertical MBQ sensor in industry • (goal finish specification end march) • Requested sensor model confirmed by B. Caron for FF • + very useful feedback on specification

16. GM measurements • Vibration measurements test module • Vibration measurements pulsed dipole • CMS RB to RB measurements • Proposal SLAC (M. Oriunno) detector technical noise measurements

17. Main open points • QDO inside detector? • Radiation hardness: Can not go without shielding • No manpower to design and test radiation hard components. More logical at later stage? • Compatibility fast and large temperature changes • Stray magnetic fields: Amplitude vs frequency?

18. Conclusion meeting • Very good contact and exchange with clear openings for collaboration • No clear overall picture for Final Focus yet but several new data • Needs info about L* • Continue modeling and testing (LAPP, ULB) • Join manpower for modeling (including luminosity) • 2nd round end of summer • Needs more information on technical noise and GM model around detector • Planning for three stabilised and aligned MBQ in 2013 • Inertial sensors in pipeline • GM measurements ATF2, possible CMS measurements • Start point for list actions and open points • Stab WG meeting two times/year + “hands on “ meetings • Next WG meeting September