news from stabilisation wg main beam quadrupole stabilisation
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News from Stabilisation WG Main Beam Quadrupole Stabilisation. News from LAPP . News from CEA. News from CERN. News from LAPP. Meeting 15 th July (Andrea, Claude, Kurt). MBQ Eigen mode analysis:. http://hal.in2p3.fr/in2p3-00480244/fr/. Report:. - PowerPoint PPT PresentationTRANSCRIPT
1K. Artoos CTC 27/07/2010
News from Stabilisation WGMain Beam Quadrupole Stabilisation
News from LAPP
News from CEA
News from CERN
2K. Artoos CTC 27/07/2010
News from LAPP
• Meeting 15th July (Andrea, Claude, Kurt)
• MBQ Eigen mode analysis:http://hal.in2p3.fr/in2p3-00480244/fr/Report:
Pole modal measurements ongoing
Free-free 279 Hz first bending frequency. Some uncertainties for supported MBQ (depends on boundary conditions). First bending modes around 250 Hz
• Active foot :PI capacitive gauges purchasedActuators installed + testedRole and behaviour elastomer not fully understood yetFirst stabilisation results foreseen in September
• More regular meetings LAPP/CERN planned from September on Closer collaboration to improve “critical mass”
• Cross check between seismometer and MONALISA
• Decision « baseline stabilisation MBQ » for CDR ?
3K. Artoos CTC 27/07/2010
News from IRFU CEA SACLAYPurchase of SIOS Triple axis interferometer 0.1 nm resolution
Borrowed device now available
Final delivery in September
Measurement through 3 mm hole confirmed
Measurement of pole tip vibrations with respect to yokeMeasurements vibrations coil and yoke water coolingCalibration actuators + hexapodCalibration tilt meters
Preparation measurements started (mirrors etc)
4K. Artoos CTC 27/07/2010
News from CERNOverall approach and work plan : See CTC # 22 Talk C. Hauviller
Claude HauvillerKurt ArtoosChristophe CollettePablo Fernandez CarmonaMichael GuinchardStef JanssensAndrey KuzminRaphael LeuxeAnsten Slaathaug
This talk: status, ongoing work and outlook
5
1. Stabilisation single d.o.f. with small weight (“membrane”)
End April CERN 2010
K. Artoos IPAC10
Steps toward performance demonstration RIGID option
Piezo actuator ( PI™): Resolution 0.1 nm Stiffness 24 N/µmMeasured vertical resonant frequency ~ 300 Hz
2.5 kg
Objective reached
6K. Artoos CTC 27/07/2010
Input from Pablo Fernandez Carmona:
Systematic study and improvement of noise levels:
Power supply seismometers
Cabling to seismometer
Noise level acquisition systemsNoise level output
Result last week on membrane:
0.6 nm at 1 Hz from 2 nm
1 nm at 1 Hz from 5 nm
P. Fernandez CarmonaS. JanssensC. Collette
« Nano-positioning »
Or “Modify position quadrupole in between pulses (~ 5 ms) “
“Range 10 μm, steps 10 to 50 nm, precision 2nm ”
Demonstration nano-positioning single d.o.f. :
For FREE
10 nm, 50 Hz
S. Janssens
Measured with capacitive gauge 0.1 nm resolution open loop
7K. Artoos IPAC10
< 1 Hz Beam based feedback: BPM + corrector dipoles
Remark: Measuring < 0.1 nm relative displacement
Catalogue products
Steps toward performance demonstration RIGID option
2. Stabilisation single d.o.f. with type 1 weight (“tripod”)
actuator
Preliminary result in noisy environment
S. Janssens
2 rigid feet
No flexural guide yet so can be improved
30 nm at 50 Hz
100 kg
Expected
Requirements for the actuating support
• Stiff• Degrees of freedom: 6 d.o.f. ?
• 0.1 nm resolution vertical• Precision and repeatability 1 – 2 nm
Flexural hinges instead of rotary joints
9K. Artoos IPAC10
Natural frequencies > 200 Hz
Parallel structure
Concept drawing
Piezo actuators
Blocking force 12.5 kNStiffness 480 N/μm *Resolution 0.15 nm
PI P-225.10
• Precise
Integrated sensor 0.3 nm
G
G
G
G
10K. Artoos IPAC10
Design 2 d.o.f. flexural hinge
Number and orientation of legs
K axial : ~ 300 N/μmK α : ~ 200 Nm/rad
Structural stiffness
Induced stresses in piezo
Inclination Resolution, structure stiffness, forces
Number # D.O.F. , COSTResonant frequency
Difficulty assembly
FE model with parameters available
11K. Artoos CTC 27/07/2010
Steps toward performance demonstration RIGID option
3. Stabilisation two d.o.f. with type 1 weight (“tripod”)
Test assembly done, this week assembly with real actuators
12K. Artoos IPAC10
Actuator pairs in same planeBlock longitudinal
Block Roll X- Y guidance
y v
Video modes singularity
13K. Artoos CTC 27/07/2010
Design x-y guide: statusConcept: hyperguided table with 8 flexural beams
Designing for a low x-y rigidity and high longitudinal and torsional rigidity
Type 1
14K. Artoos CTC 27/07/2010
Additional functions x-y guide:
• Add a direct measurement of the x-y displacement with respect to intermediate platform
To replace instrumentation in legsHas a zero position (reference mark on grating) !Sensitivity and noise level does not change with
position (unlike capacitive gauges)Less strict alignment requirements sensorCould become low cost for large serie
LIP 281 Linear encoder 1 nm/TTL
• Introduce the possibility to protect piezo actuators during transport
• Should make it possible to reduce the number of actuators.
• The x-y guides can be built together to form a girder around the magnet as the intermediate platform between alignment and stabilisation
15K. Artoos IPAC10
Alignment :
Stiffness other components: magnet and support
F. LacknerEccentric cams. First prototype based on SLS (PSI)
• Beam height reduced to 620 mm
• Alignment with Eccentric cams at Airy points
• Stabilisation actuator pairs above cams
Ground broadband excitation amplified at support and magnet resonances
16K. Artoos CTC 27/07/2010
Steps toward performance demonstration RIGID option
4. Stabilisation two d.o.f. with type 4 weight
Type 2 to type 4 will be an extension/duplicate of type 1.
Price enquiry for 6 actuators being prepared.
Too late for CDR draft end september.
17K. Artoos CTC 27/07/2010
Stabilisation control strategy Christophe ColletteStef Janssens
Comparison different control/sensor strategies
Contact with seismometer companies to produce a « inertial reference mass » to replace the broadband seismometers or to remove their inconveniences
To be presented in September ISMA conference + ref. MEDSI presentation 2010Force sensing methods at higher frequencies
Controller for 2 degrees of freedom for stabilisation and nano positioning.
Ongoing work:
Improvement stability + increase the performance
Model for 6 degrees of freedom type 4 for interaction with BBF.
Publication in Physical Review, special topics: accelerator and beam.
18C. Collette MEDSI
19K. Artoos CTC 27/07/2010
Sensor characterisation:
« Bungee table » for noise characterisation seismometers
Ansten SlaathaugMichael Guinchard
Characterisation and research noise and sensitivity seismic accelerometers, low noise amplifiers, Conditionners,…
Ongoing:
20K. Artoos CTC 27/07/2010
Vibration source characterisation:
Ongoing:
• Ground excitation by shaker with a known frequency/spectrum and amplitude and propagation measurement in different floors. • Planned measurements surface CMS for final focus
• As soon as MBQ prototype is available we can do measurements with water cooling: vibrometer + LASER interferometer will be available.
Michael GuinchardAnsten Slaathaug
• Possibility to do vibration measurements for module, but Measurement Lab highly loaded with other CERN projects: ressource critical.
• Planned measurements of efficiency passive damping systems for pumps etc.
21K. Artoos CTC 27/07/2010
Conclusions
Steady progress on steps towards demonstration of feasibility.
Not at the same pace as CDR. Importance to have convincing intermediate steps.The schedule is not always in our hands + too many CLIC meetings… (?)
The team put in place begins to pay off, important to keep continuity long enough (WP).
It would help to have a dedicated work space as can be found in other places doing this kind of work: temperature stable, low vibration back ground, « clean » electrical network, cooling water network, lifting and handling,…. ***