cea dsm irfu sis 9th stabilization meeting status of pole tips measurement

CEA DSM Irfu SIS

9th stabilization meeting

Status of pole tips measurement

CEA DSM Irfu

Status

• Choice of the measurement device– Requirements– Tests results– Chosen sensor configuration

• Pole tips measurement on CERN mock-up (dec. 2010)– Measurement configuration– Solutions to be studied

• Preliminary tests at Saclay– Glue tests– Reflecting surface– Mechanical support– Measurement intent on IPHI mockup

• Planning

25/09/2008 -MichelFontaine- CLIC Stabilisation ("pied de page" et "date" -> onglet menu Affichage/En-tête) 2

CEA DSM Irfu25/09/2008 -MichelFontaine- CLIC Stabilisation ("pied de page" et "date" -> onglet menu Affichage/En-tête) 3

Choice of the measurement device : requirements

– Requirements :

– Characteristics to be described

Amplitude accuracy 1nm and <

Amplitude resolution 0.1 nm and <

Frequency range 1 to 100 Hz

Measurement frequency >400 Hz

Maximum velocity 1 m.s-1

Ability to cross a 60mm long hole in the yoke Max 6mm diameter

Interferometer’s type Michelson, Fabry-Pérot, Doppler…

Acquisition system Analog/digit - I/O

Other parameters acquisition requirement Temp, press, hygrometry, etc…

Reflecting surface λ/? Reflection necessary for optimal measurement

Measurement distance range 0 to …? m

Other requirements Protection, vacuum conditions, influence of magnetic fields, etc…


Choice of the measurement device : tested sensors

Instrument

Characteristics

RENISHAW ATTOCUBE SIOS POLYTEC FIBER

VIBROMETER

INTERFEROMETER TYPE

Michelson Fabry Pérot Michelson Doppler

Differential mode Yes No No Yes

Distance measurement range

0 to 0.6m 0 to >1m according to the sensor

According to the sensor

According to the focusing lens range

Special requirement

Protection from turbulences



To be determined

Cost (k€) 70 to 100 30 to 50 40 40 to 60

Validation No No Yes No


Choice of the measurement device : POLYTEC fiber vibrometer tests results

90 100Hz

1p

10p

100p

1000p

10n

100n

1µ

10µ

m

Geophone_VVibrometerCap Sensor

100 .0 [H z ] 2 .3e-7 [m ] 0 .0 [s ]

90 100Hz

1p

10p

100p

1000p

10n

100n

1µ

10µ

m

Geophone_VVibrometerCap Sensor 100 .0 [H z ]

1 .6e-8 [m ] 0 .0 [s ]

90 100Hz

1p

10p

100p

1000p

10n

100n

1µ

10µ

m


100 .0 [H z ] 3 .2e-9 [m ] 0 .0 [s ]

1 10Hz

1p

10p

100p

1000p

10n

100n

1µ

10µ

m


10 .0 [H z] 1 .9e-7 [m ] 0 .0 [s ]

1 10Hz

1p

10p

100p

1000p

10n

100n

1µ

10µ

m


10 .0 [H z] 1 .8e-8 [m ] 0 .0 [s ]

1 10Hz

1p

10p

100p

1000p

10n

100n

1µ

10µ

m


10 .0 [H z ] 1 .9e-9 [m ] 0 .0 [s ]

100 Hz

BadGood

ampl 230nm ampl 16nm

ampl 3.2nm

ampl 190nm ampl 18nm

ampl 1.9nm

Capacitive senson

Geophone

Vibrometer

10 Hz

Tests results on CERN bench (graphics by M. Guinchard)

Impossibility to have a measurement result at 1 Hz : sensor rejected

CEA DSM Irfu

Choice of the measurement device : chosen sensor configuration

• Available configurations


Commercial config.

Reflector type Max. speed

Resolution (nm)

Range measurement (mm)

Connected sensors per acquisition unit

Price (k€)

Triple axis SP-TR

λ/10 mirror 0.8 0.1 to 1 according to working distance

0 à 2500 1 40

Adjustable focus LSV

All type of reflecting surface

1.5 0.1 240 à 2500 3 25

Mono-axis SPS

All type of reflecting surface

λ/10 mirror for max. resolution

1.5 0.3 30 à 70, 240 3 20

• Chosen configuration (02/08/2010 meeting CR-MF/2010-1990a) :

• 3 axis working on differential mode or independently• Angle measurement available ±0.3 mrad• Beams distances 13mm• I/O analogical or digital-32bit mode (atmosphere correction factor included

on digital mode only)


Pole tip measurement on CERN mockup : measurement configuration

1

32

1- measurement on yoke 3- measurement on pole2- measurement on pole

(2-3) horizontal wave propagation on pole tip

(1-2) and (1-3) vibration measurement between yoke and pole tip

1

32

1

32

Measurement conditions Purpose Results

No controlled vibration See cultural noise influence on pole tips

FFT spectrum

Calibrated vibration on yoke See propagation on yoke and poles

FFT spectra and propagation diagrams

Calibration vibration on girder See girder’s influence on transmitting vibrations

FFT spectra and propagation diagrams

3 measurement positions

CEA DSM Irfu

Pole tips measurement on CERN mockup : solutions to be studied

• All tests can be performed before on a similar device at Saclay


Supporting sensor

Drilling hole (angle and diameter)

Reflecting surface (glued or polished?)

Girder and actuators for controlled movements

CEA DSM Irfu

Preliminary tests at Saclay : glue tests and reflecting surface choice

• Purpose : – Verify that no damping due to the glue alter the

displacement measurement– Choose the glue type (wax, araldite, other?)– Time effects on glue– Test :


Signal comparison

OK : mirror glued

NO: surface to be polished

CEA DSM Irfu

Preliminary tests at Saclay : mechanical support design

Mechanical problem Option chosen for Saclay test

Vibrometer support Glued or tightened on the yoke or independent

Reflecting surface mounting Mirror glued on an invar made wedge

Hole drilled in yoke Ø3mm wished, test on a vibrometer next Thursday


CEA DSM Irfu

Preliminary tests at Saclay : measurement intent IPHI mockup


Reflecting surface and glue tests

Vibration transmission tests

Sensor mechanical

interface

Hole diameter test


Planning

Task J F M A Ma Ju J Ao S O N D J F M

Sensor bought and delivered

Reflector and sensor tests

Mechanical interface design

Measurements on IPHI mockup

Design and fabrication of mechanical interface for CERN mockup

1 point measurement on CERN mockup

N points measurement on CERN mockup

CEA DSM Irfu

Next steps

• Hole diameter test on Thursday

• Sensor device order march-april

• Sensor delivery 12 weeks after (?)

• Mirrors and wedges bought in march


cea dsm irfu sis 9th stabilization meeting status of pole tips measurement

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