Stabilisation status and integrated simulations

1. Stabilisation status and integrated simulations A.Jeremie

2. FF stabilisation • Criteria to give a direction of study: • 0.15nm above a few Hz (4Hz to compare to previous studies) for the mechanical stabilisation • 0.1nm at 0.1Hz for the integrated study (including mechanical stabilisation, pre-isolator, beam feedback, Adaptive feedback)

3. LAPP and SYMME contribution to a “stable” CLIC accelerator Beam Physics Daniel Schulte Accelerating structures Technical design Hermann Schmickler Costing CTF3 CLIC Beams Ctee CLIC Technical Ctee Activity 4: Integrated feedback => Choice of controller, overall performance B.Caron and A.Latina Activity 1: Stabilisation technology => Sensors, actuators, stabilisation system (incl.feedback, electr.) A.Jeremie and K.Artoos Activity 2: Apply to MB quad => MB quad simulations and measurements K.Artoos Activity 3: Apply to FF quad => QD0 proto measurement, integration (hardware + beam physics) L.Gatignon Integration, simulations, physics A.Latina Stabilisation WG K.Artoos MDI WG L.Gatignon A.Jeremie 10/01/2011

4. Activity 1Stabilisation technology =>Sensors, actuators, stabilisation system (incl.feedback, electr.)

5. Stabilisation technology What we need Issues Commercial sensors studied, some identified, but still need to work with accelerator Commercial actuators working in the nm resolution are often limited in force and fragile Find real time systems ( + electronics) that have a sufficient range and resolution • Need to measure nm in accelerator environment without disturbing the structure • Need to act on the structure to be stabilised (several kg) • Feedback for vibration control

6. Specific to MDI What we need Issues “absolute” sensors large compatibility with the other components in crowded space Compromise between total range and resolution Non-vibrating QD0 => measurements on future prototype • Very compact system to fit inside the detector • Very tight vibration criteria

7. Instrumentation (measure, act, control) Need to be light, compact, lowfrequency, nm, rad hard, resistant to magneticfield Passive and active isolation Real time material

8. Sensors We had identified 3 types of sensors for “absolute” measurement: • Endevco (piezo accelerometers): manufacturing discontinued, replaced by Wilkoxon; seem a little less performing but OK; need to test=> but low signal to noise ratio at low frequency • Güralp (geophones): our sensors had been sent for calibration and repair (some re-centering) but some confusion has delayed the return of the sensors. Should be back today. => but big and heavy • SP500 (chemical sensors): decided with Kurt that LAPP will re-examine them (for comparison, we prefer to have the Güralp before starting). => seem to degrade with time • Will we need to develop a dedicated sensor? If we get the French ANR financing, a new partner will look into this issue.

9. Sensors • Inside the LAPP stabilisation system, for compactness reasons, “relative” sensors have been chosen, the “absolute” measurement being done at a more “practical” location. PI D-015 240mm

10. Actuators In the past, because of “historical” contacts, we decided with Kurt that CERN concentrate on PI actuators and LAPP on Cedrat actuators for performance evaluation. • For the stabilisation “feasibility” demonstration we used APA60S • For the stabilisation system, we use PPA10M. CERN is using PI actuators, but in addition have made an extensive mechanical, flexural joint and rigidity study to avoid any shear Our stabilisation system uses elastomer for guidance.

11. I/O Acquisition system • We have started the stabilisation system instrumentation tests with dSPACE 16 bit system. • For the initial tests, sufficient for the measurements, but will need to study an upgrade. • An electronics engineer will help us (very small part time…!) during the tests.

12. First tests in Annecy Mid-lower magnet Lower electrode of the capacitive sensor V-support for the magnet 1355mm Elastomeric strips for guidance 240mm Fine adjustments for capacitive sensor (tilt and distance) Piezoelectricactuator below its micrometric screw 2mV=0.1nm IWLC2010 Geneva 2010 A.Jeremie Next step: add feedback

13. Status • Stabilisation system has moved to SYMME for feedback implementation tests. • Room has been better adapted to the measurements • Real Time dSPACE system is in place • Additional sensors are being installed (there was only one for initial evaluation tests, now the 4 planned sensors have arrived) • Tests start now

14. Activity 2:Apply to MB quad => MB quad simulations and measurements Not MDI… so will skip this activity Although experience gained through this activity will benefit MDI Some planned measurements have to be adapted to recent changes in pole procurement: imminent discussion with Kurt

15. Activity 3:Apply to FF quad => QD0 proto measurement, integration (hardware + beam physics)

16. Hardware integrationWhat it looks like in the CDR H.Gerwig + N.Siegrist

17. Beam trajectory control( also activity 4) Preliminary!!!!! • Preliminary results, not checked nor digested… • Just to show what we are working on: a more complete presentation will come in due time • Comparison FB, AFB and noise • Pre-isolator used (very similar to initial filter used) • Independent optimisations: each FB has it’s own optimal parameters • Compare “CMS” GM and “B” GM

18. Comparisons done in simulations Pre-isolator is used in all simulations The following GM and noise curves are used: CMS B noise 13 pm

19. Summary of integrated rms at 0.1Hz Preliminary!!!!! • The red color indicates that the simulation has been done using ground motion from CMS. The green one corresponds to the model B generated by PLACET. • FB: “classical” PLACET feedback • AFB: FB + Annecy Adaptive feedback • PID: Parameter optimisation for comparison • APID: PID + adaptive PID

20. Some sample figures Preliminary!!!!! PSD and RMS with PLACET optimization, pre-isolator and AFB. PSD and RMS with PLACET optimization, 13pm white noise, pre-isolator and AFB.

21. Planned activities • Tests on stabilisation system with 4 sensors are starting now (validate sensors, actuators, feedback and electronics) until at least June 2011 • Work on chemical sensors (calibration, noise measurements, contact manufacturer and users, long term stability measurements) June 2011 and more? • Start thinking of set-up to test sensors in accelerator environment • Work on the integrated simulation: when results digested, decide with Daniel and Andrea L. what to include in CDR (before the 2011 CDR correction deadline!)