STABILISATION WG MEETING 1121th FEBRUARY 2013

CTC SUMMARY

The research leading to these results has received funding from the European Commission under the FP7 Research Infrastructures project EuCARD

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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

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CERN S.Janssens (Fellow) 100%K.Artoos (50%)Designers: R. Leuxe, C. Eymin (jobs)

A. Gaddi, H. Gerwig, F. Ramos LS1

MBQ stabilisation + nano-pos.Sensor development

Pre isolator studies

LAPP/Symme

A.Jeremie, G.Deleglise 20%Additional physicist requestedL. Brunetti (70%), J.Allibe (=> July 2013)G. Balik (=> Sept. 2014), J.P. Baud 40%S. Vilalte (20%)SYMME: B. Caron

Final focus stabilisationSensor development

ASL (ULB)

Chr. Collette , D. Tshilumba, J. Amar (PhD, Master students)“Brains back to Brussels” Grant until end 2013 (could be extended)

Controller designs MBQ & Final FocusSensor R&DNetworking

CEA/IRFU

F. Ardellier DesagesM. Fontaine, N. Pedrol-Margaley(no %, K contract finished)

Optical measurement methodsCalibration standardMeeting at CEA to be planned

Manpower + collaborationstatus

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Final focus stabilisation

40 to 100 ton pre-isolatorFrequency 1-2 Hz

CAM based alignment system

Cantilever 50 Hz

Active stabilization system

IP Beam based feedback

So far no link was made between all systems (control)

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Ongoing work FF

• IP Beam based feedback• Mechanical stabilisation

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Ongoing work FF

• Precise model• Noise of sensors limits stability reached

1. Tests with other sensor Guralp 3ESP+ Better noise curve than Guralp 6T- More difficult transfer functionImplementation ongoing- Size of sensor

2. Development sensor (patent)

Prototype 1 ready and being testedMiniaturized prototype 2 end of MarchApril: testing on active support

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Ongoing work FF

• Study of active cables to damp cantilever

(CLIC/ILC) + possibility positioning+ improves transfert function+ Improves stiffness against direct forces- Implementation of cables in push pull detectorChristophe showed possible control strategies and

showed 3 limitations due to:1. Sensor tilt to horizontal coupling2. Flexible connections between sensor and actuator3. Flexible support

Advice to have an intermediate soft support (20Hz)

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Ongoing work FF

What is needed to damp/influence peak of pre-isolator mode?

S. Janssens

Comparison several strategies

Velocity feedback xp Combination x and xp feedback

Issues pre-isolator: 1. Ground motion at 1 Hz > 12 m is not coherent (LHC GM measurements), active damping and transmissibility reduction at 1 Hz is needed2. Compliance too high, demonstrated with small airflow3. Maximum 1 µrad roll allowed for luminosity4. Cantilever is huge lever arm, requiring even higher resolution on pre isolator actuators

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Ongoing work FFS. Janssens

PID on xp + activ stab. Possible transfer function between ground and QD0 + no drift at low freqPossibility to change Preisolator position!!!No noises or filters in it!!!!

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Final focus stabilisation

Open points:1. QD0 inside detector ? No decision next two years2. Mechanical Design pre isolator is linked to having the magnet inside the detector or not3. Noise model near particle detector should be studied/measured. Coherence ?4. For FF go from integrated RMS to integrated luminosity, model and test different solutions5. Make the link between the two FF and between FF and BDS and MBQ for multiple d.o.f.6. 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 modelsStudy existing hardware components: contact industry for existing components

We need to set a clearer target for FF

Further Research proposal (tender/inhouse)

Research goals1. 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

Requires a student

K.Artoos, Stabilisation WG , 21th February 2013

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MBQ: build 3 modules “best available design”

Functional performance testing + development time: Study and try assemblyRequires controlled stable environment (Temperature, Vibrations, Access)Demonstration feasibility + ultimate performance stab. + positioningWater cooling + powering magnet

Test module location not adapted for this.Magnetic measurements and fiducialisation

Type 1 Test module with dummy magnetIntegration in test module, connections to other modules, robust show case, transport, …Demonstration alignment and stabilization but not representative for CLIC tunnel

Type 1 ISR

Type 4 ISR

Type 1 CLEX

Type 4 Test module

MBQ modules upgradable (bolted together, no welds).

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Main beam quadrupole stabilisation

Design and end of drafting MBQ type 1 stabilisation for ISR tests + CLEX, Testmodule:     Week 11Fabrication type 1: 1.5 monthStart assembly type 1: end of April,  Assembly 1 weekController electronics type 1 ISR ready : end of AprilTesting 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 MarchFabrication 1.5 monthStart assembly type 4: Middle of May, assembly 1 week.Controller electronics type 4 ready: end of MayTesting type 4 ISR stabilisation: June, July

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Combine with alignmentPresentation Juha

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Sensor developments

• 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

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GM measurements

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

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Main open points

• QDO inside detector?• Radiation hardness: Can not go

without shieldingNo 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?

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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 summerNeeds 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