MECHANICAL STABILISATION OF CLIC QUADRUPOLE MAGNETS VIBRATION STABILIZATION

MECHANICAL STABILISATION OF CLIC QUADRUPOLE MAGNETS VIBRATION STABILIZATION AND NANO POSITIONING 17. 10. 2017 K. Artoos

MECHANICAL STABILISATION OF CLIC QUADRUPOLE MAGNETS 2008 -2017 K. Artoos , C. Collette (ULB), M. Esposito, C. Eymin, P. Fernandez Carmona , S. Janssens (NIKHEF), R. Leuxe, H. Mainaud Durand, M. Modena CEA IRFU A. Jeremie, J. Allibe, L. Brunetti, J. -P. Baud, G. Balik , G. Deleglise, S. Vilalte, B. Caron, C. Hernandez, M. Fontaine D. Tshilumba, J. Spronck, J. Herder

3 48 km Main beam q Vert. Beam size 1 nm at IP q Hor. Beam size 40 nm at IP q Beam every 20 ms q 2 x 2000 MB Quadrupole magnets Challenges: q Beam emittance preservation Alignment of components Quadrupole magnet stability ~40 nm 1 nm

Ground motion 4 20 km See talk Michael

Luminosity, beam size and alignment 5 Integrated r. m. s. displacement Possible mitigation techniques: • Alignment (17 µm / 200 m) • B. P. M. + dipole correctors f • B. P. M. + Nano positioning • Seismometers + Dipole correctors • Mechanical stabilization with seismometers Requirements Mechanical stability: Vertical MBQ 1. 5 nm at 1 Hz Vertical Final Focus 0. 2 nm at 4 Hz Lateral MBQ, FF 5 nm at 1 Hz 5 nm at 4 Hz BUT Final requirement is Integrated Luminosity

Vibration Isolation Strategies 6 Earth quake protection Big Physics projects Space Chip manufacturing (Lithography) Daily life Big civil engineering projects S. Janssens, P. Fernandez, A&T Sector Seminar, Geneva, 24

Passive Isolation Strategies 7 Passive Isolation Transmissibility Isolation Trade off between magnification at resonance and isolation S. Janssens, P. Fernandez, A&T Sector Seminar, Geneva, 24

Passive Isolation Strategies 8 Effect of support stiffness [m/N] • Watercoolin g • Accoustics • Ventilation Transmissibility Compliance Soft support : Improves the isolation Make the payload more sensitive to external forces Fa S. Janssens, P. Fernandez, A&T Sector Seminar, Geneva, 24

requirements stabilisation support 9 Stiffness-Robustness Applied forces (water cooling, vacuum, power leads, cabling, interconnects, ventilation, acoustic pressure) -Compatibility alignment -Transportability/Installatio n Available space Accelerator environment (AE) Integration in two beam module. High radiation 620 mm beam height Stray magnetic field Integration in cantilever tube FF

Active Isolation Strategies Feedback control principle S. Janssens, P. Fernandez, A&T Sector Seminar, Geneva, 24 Novemb

Practical application 11 Very Soft (1 Hz) Soft (20 Hz) Stiff (200 Hz) • Pneumatic actuator • Electromagnetic in parallel • Piezoelectric actuator in series with stiff element • Hydraulic actuator with a spring (flexible joint) • Piezo actuator in series with soft element (rubber) k~0. 01 N/µm k~1 N/µm COMPARISON + Broadband isolation - Stiffness too low - Noisy C. Collette Piezo k~100 -500 N/µm + Extremely robust to forces + Fully compatible with AE + Comply with requirements S. Janssens, P. Fernandez, A&T Sector Seminar, Geneva, 24 - Noise transmission + Passive isolation at high freq. + Stable - Low dynamic stiffness - Low compatibility with alignment and AE

Concept for MBQ Actuating support 12 • Inclined stiff piezo actuator pairs with flexural hinges (vertical + lateral motion) (four linked bars system) • X-y flexural guide to block roll + longitudinal d. o. f. + increased lateral stiffness. Flexural pins

Concept for MBQ Actuating support 13 Piezo stack actuators q q Resolution: 0. 15 nm Stiffness : 480 N/ m Stroke: 15 µm Blocking force: 12. 5 k. N

Combined FB + FF 14 Transmissibility S. Janssens, P. Fernandez, A&T Sector Seminar, Geneva, 24

Concept demonstration actuator support with staged test benches 15 Collocated pair EUCARD deliverable Type 1 Seismometer FB max. gain +FF (FBFFV 1 mod): 7 % luminosity lo (no stabilisation 68 % loss) X-y proto

RMS ratio 16 S. Janssens, P. Fernandez, A&T Sector Seminar, Geneva, 24

Long Term Stability 17 Objective S. Janssens, P. Fernandez, A&T Sector Seminar, Geneva, 24

Stabilization milestones 18 Objective 1. 5 nm r. m. s. General purpose PXI Analogue controller Membrane July 2009 Feedbac k FB + FF Hybrid controller Tripod June 2010 Type 1 September 2011 Custom cables and shielding Analogue = less latency 3. 5 nm Ratio: 1. 5 1. 2 nm Ratio: 1. 8 0. 8 nm Ratio: 2. 5 Remote configurable Board optimization 0. 7 0. 5 nm 0. 3 nm 0. 6 nm nm Ratio: 1 Ratio: 6 Ratio: 5 Ratio: 3 S. Janssens, P. Fernandez, A&T Sector Seminar, Geneva, 24 9

Controller electronics: Hybrid 19 Local electronics ADCs digitize signals For remote monitoring Communication to remote control cente with optical fiber 2 analogue chains + positioning offset Configurable parameters Gain Feedforward Gain Feedback Lag pole and zero frequencies Lead pole and zero frequencies Output offset (positioning) Feedforward low pass filter frequency S. Janssens, P. Fernandez, A&T Sector Seminar, Geneva, 24 SPI

Status CLIC Nano. Stabilisation 2017 20 • Stabilisation re-demonstrated in 2015 with hybrid electronics (remotely controlled) on real type 1 prototype (Stef Janssens)

Vibration sensor Inertial mass 21 Stabilisation Michelson Stabilised LASER Also PACMAN subject : P. Novotny

Integrated luminosity simulations 22 Commercial Seismometer No stabilization 68% luminosity loss Seismometer FB maximum gain 13% (V 1) Seismometer FB medium gain 6% (reduced peaks @ 0. 1 (V 1 mod) and 75 Hz) Seis. FB max. gain +FF 7% Custom Inertial (FBFFV 1 mod) Reference mass Inertial ref. mass 1 Hz (V 3 mod) 11% Courtesy J. Snuverink, J. Pfingstner et Stef Janssens K. Artoos, Stabilisation WG , 21 th February 2013 Inertial ref. mass 1 Hz + HP filter 3%

Nano positioning 23 « Nano-positioning» feasibility study Modify position quadrupole in between pulses (~ 5 ms) Range ± 5 μm, increments 10 to 50 nm, precision ± 0. 25 nm • Lateral and vertical • In addition/ alternative dipole correctors • Use to increase time to next realignment with cams

X-y prototype: Demonstration Nano positioning Resolution, precision, accuracy 24 Capacitive sensor 3 beam interferometer Actuators equipped with strain gauges Optical incremental encoder

X-y positioning: Study precision, accuracy and resolution 25 The precision required (0. 25 nm): • demonstrated with optical rulers • in a temperature stable environment , in air • for simultaneous x and y motion. • Still increase speed

Comparison sensors 26 Sensor Resolution Main + Main - Actuator sensor 0. 15 nm No separate assembly Resolution No direct measurement of magnet movement Capacitive gauge 0. 10 nm Gauge radiation hard Mounting tolerances Gain change w. Orthogonal coupling Interferometer 10 pm Accuracy at freq. > 10 Hz Cost Mounting tolerance Sensitive to air flow Orthogonal coupling Optical ruler 0. 5*-1 nm Cost 1% orthogonal coupling Mounting tolerance Small temperature drift Possible absolute sensor Seismometer (after K. Artoos, Stabilisation WG , 21 th February 2013 < pm at higher For cross calibration Rad hardness sensor head not known Limited velocity displacements

Displacement sensors 27 + actuator gauges, interferometer + seismometers (calibration)

Status CLIC Nano. Positioning 2017 28 David Tshilumba (PACMAN) • Upgraded the type 1 MBQ prototype • Removed resonances < 100 Hz • Demonstrated required accuracy in Leitz infinity CMM • Demonstrated required precision • Developed controller to move magnet 50 nm in 20 ms Workpackage stabilisation now «on

Conclusions 29 CLIC MBQ required stability was demonstrated in a lab environment on the smallest MBQ Type 1 Nano positioning was also demonstrated on type 1. Large scale implementation and in radioactive environment still requires an R&D effort.

Performance limitations of a mechatronics system Freely adapted from J. Moerschell 30 Noise • • • Temperature Electrical noise (Johnson, …) Electromagnetic noise SEU Digitalisation, quantisation Spurious noise, cross talk Material • • Elasticity, elastic limit, stress limit Damping Fatigue Ageing (Radiation, Curie-T, humidity) Mechanics • • • Dimensions, mass, stiffness Range Degrees of freedom Precision guidance Modal behaviour Control • • • Non linearity Bandwidth, instabilities Control delay Parameter uncertainties Controller authority, collocation

Mass/Actuator Resolution/ Range/k/ Bandwidth 31 A Bandwidth is limited by • Actuator slew rate Amplitude Remark about load compensating springs: Force Range Load compensation reduces range + bandwidth Improves resolution * Frequency

Machine precision vs size C. Collette 32 Te ch no log ica l li m ita tio n fo r l ar ge r c om po ne nt s K. Artoos, Stabilisation WG , 21 th February 2013