Main beam Quad Stabilisation: Status of the stabilisation test program at CERN CLIC-stabilization day S. Janssens Contribution to slides by: C. Hauviller, C. Collette, S. Janssens, M. Guinchard, A. Jeremie, A. Slaathaug, M. Guinchard S. Janssens, CLIC stabilization day

Requirements Stability Values in integrated r.m.s. displacement at 1 Hz C. Collette Final Focus quadrupoles Main beam quadrupoles Vertical0.1 nm > 4 Hz1 nm > 1 Hz Lateral5 nm > 4 Hz5 nm > 1 Hz S. Janssens, CLIC stabilization day

CERN option: Steps toward performance demonstration Step 1:Stabilisation single d.o.f. with small weight(“membrane”) Step 2: Stabilisation single d.o.f. with type 1 weight(“tripod”) Step 3:a. Inclined leg with flexural joints b. Two inclined legs with flexural joints c. Add spring guidance d. Test equivalent load per leg Step 4:Stabilization of type 4 (and type 1) Main beam Quadrupole S. Janssens, CLIC stabilization day

CERN option: Steps toward performance demonstration 1. Stabilisation single d.o.f. with small weight(“membrane”) 1.2 nm First result: S. Janssens, CLIC stabilization day Membrane: Technology test bed First experience with controllers Good first results (old)

1. Stabilisation single d.o.f. with small weight(“membrane”) S. Janssens Feedback 5.5 nm down to Hz Feedback CERN option: Steps toward performance demonstration Feed back Improved feedback: 10 Hz ~0.3 (Improved from 0.5) Integrated RMS 1Hz Improvements under investigation

1. Stabilisation single d.o.f. with small weight(“membrane”) CERN option: Steps toward performance demonstration Details theoretical model: Matlab Standard control loop design Plant G: Membrane Sensor H: Geophone Controller D: Control G Test several sensors Test Vibration isolation systems

1. Stabilisation single d.o.f. with small weight(“membrane”) CERN option: Steps toward performance demonstration Theory vs measurement: Transferfunction Measurement better< 2 Hz Phase Diff. > 40 Hz Conclusion: Model is good representation 2-40 Hz Differences between theory and Measurements are under investigation

Option CERN: Rigid support and active vibration control Bonus: possibility to nano position the Quadrupole Ref. D. Schulte CLIC-ACE4 : “Fine quadrupole motion” “Modify position quadrupole in between pulses (~ 5 ms) “ S. Janssens Experiment set-up Signal from PXI to actuator 10 nm, 50 Hz Openloop Measured with PI capacitive gauge S. Janssens, CLIC stabilization day Requirements Range: 20 μm Precision: 2nm

Option CERN: Rigid support and active vibration control Bonus: possibility to nano position the Quadrupole Ref. D. Schulte CLIC-ACE4 : “Fine quadrupole motion” “Modify position quadrupole in between pulses (~ 5 ms) “ S. Janssens S. Janssens, CLIC stabilization day Result: Noisy step function ->caused by PXI Actuator follows input signal Precision < 2nm

CERN option: Steps toward performance demonstration 2. Stabilisation single d.o.f. with type 1 weight(“tripod”) actuator 2 passive feet Tripod 50 kg mass (proportional type 1) Piezo actuator 2 passive feet Feedforward Geophone Feedback Geophone Controller in Labview Prepared for next stages in design

CERN option: Steps toward performance demonstration 2. Stabilisation single d.o.f. with type 1 weight(“tripod”) actuator Preliminary result Expected Tripod first results 10Hz tf ~0.5 Simulation done with transfer function for tt1 -> Close to 1nm up to ~ 1.5 Hz Computer model is being built Characterization and improvements under research S. Janssens 2 passive feet

CERN option: Steps toward performance demonstration 3. Stabilisation two d.o.f. with type 1 quadrupole weight (“tripod”) 3a. Inclined leg with flexural joints 3b. Two inclined legs with flexural joints 3c. Add a spring guidance 3d. Test equivalent load/leg y x Load compensation Precision guidance Reduce degrees of freedom Reduce stress on piezo Status: Launch first prototype flexural hinges Status: Modelling Goal: start tests March 2010 Goal: start tests May 2010 (Status: start design) S. Janssens, CLIC stabilization day

CERN option: Steps toward performance demonstration 4. Stabilisation of type 4 (and type 1)CLIC MB quadrupole proto type Results Tests 1 to 3 Cost analysis (number of legs= cost driver) Stress and dynamic analysis Range nano-positioning Resolution # degrees of freedom Design for the 4 types Goal: start assembly and testing on type 4 prototype summer 2010 Results autumn 2010 Lessons learnt step 1 to 3 S. Janssens, CLIC stabilization day

Stabilization: Steps toward performance demonstration Sensor Research CERN: Guralp T6D seismic Geophone: nm Integrated RMS 1 Hz Magnetic field Radiation ->standard electronics in the tunnel suffers high failure rate (Sophie Mallows Thomas Otto CLIC Two-Beam Module Review )CLIC Two-Beam Module Review Other possibilities: Accelerometer (ex. ENDEVCO model 86, PCB 393B31) Optical seismometer STS-1 experiment (IRIS) … S. Janssens, CLIC stabilization day Optical STS-1 ENDEVCO STS-2 PCB

Stabilization: Steps toward performance demonstration Sensor Research Optical seismometer STS-1 experiment (IRIS) S. Janssens, CLIC stabilization day Optical STS-1 Optical STS-1 experiment: Laser light with retro reflectors Seismic mass with leaf-spring Very low noise levels Accelerator environment -> ?

Stabilization: Steps toward performance demonstration Seismometer STS-2 (IRIS) S. Janssens, CLIC stabilization day Guralp T6 Range: 0.1 – 100Hz Poles: 6 Range: – 15 Hz Poles: 11 poles No noise info yet Guralp STS-2 Sensor Research

Stabilization: Steps toward performance demonstration Guralp T6 S. Janssens, CLIC stabilization day Optical STS-1 Membrane Rootlocus (z-transform) Guralp T6 Membrane Model: H = Guralp T6 Root locus in z-transform (f = 5000 Hz) 6 poles due to Geophone Complex to stabilize with Controller Sensor Research

Stabilization: Steps toward performance demonstration Seismometer STS-2 (IRIS) S. Janssens, CLIC stabilization day Rootlocus (z-transform) STS-2 Membrane Membrane Model: H = STS-2 Root locus in z-transform (f = 5000 Hz) 11 poles due to STS-2 Much more complex to stabilize STS-2 Sensor Research

Stabilization: Steps toward performance demonstration ENDEVCO accelerometer S. Janssens, CLIC stabilization day Optical STS-1 Rootlocus (z-transform) STS-2 Membrane Membrane Model: H = Endevco Accelerometer (requested) Root locus in z-transform (f = 5000 Hz) 2 poles due to Accelerometer Much more easy to stabilize ? Sensor Research

Stabilization: Steps toward performance demonstration S. Janssens, CLIC stabilization day Optical STS-1 Guralp : 0.1 Hz PCB: ~10 Hz Endevco+Amplifier: ~2 Hz ENDEVCOPCB PSD A.Slaathaug M. Guinchard Sensor Research

Stabilization: Steps toward performance demonstration S. Janssens, CLIC stabilization day Optical STS-1 PCB Guralp T6STS-1 (opt)STS-2ENDEVCOPCB Noise level++?- Hz) Accelerator Environment - ??? Stabilization complexity Nothing meets requirements -> We all have a problem -> Research needed in Sensors Sensor Research

Conclusions CERN: Stabilization 1.2 nm at 1 Hz reached with membrane First tripod tests look promising Very low background technical noise required with present results Several steps to be taken before final design CERN: Positioning Nano positioning demonstrated Sensors Research needed for Sensors used in an accelerator environment S. Janssens, CLIC stabilization day