Status onMONALISA

presented by D. Urner

6th stabilization day

9. June 09

Progress on mechanical setup

• Double bellow system:

Vacuum

~1.4 bar pressure

SMC ITV1050Pressure Regulator

to compressedAir supply(~2.0 bar)

Vent

SMCPSE510PressureSensor

SMCPSE511PressureSensor

SMC ECC-PNAL2

Controller

• Idea: Generated Force is proportional to sum of pressure in inner and outer bellow system. – Find Point where force is zero

• Use commercial control system.

Active Double Bellow

Progress on mechanical setup

• Double bellow system:– development geared

towards minimal force system

– development with Platine Prcision Ltd. started Sep 08

– full assembly of double bellow to double flanges this week

– shipped to Oxford by end of week

Mechanical Vacuum system:

1st mode frequency: 266Hz.

• FEA shows very high resonance frequencies

• 2cm aluminium plate bolted to M30 taped holes in Shintake table

• Entire structure made from aluminium.

• Bellows: – actual bellows: stainless

steel 316L– flanges: stainless steel: 304L

1st mode frequency:162 Hz.

How to insert optics

• Insert optics platform– rests on very thin

aluminium floor– essential a square

piece of carbon-fibre loaded peak (plastic) holding retro-reflectors

– easy to change to different (optics) geometries

Calibration Study

• Does system self-calibrate?– This means: calibration by making measurements at

many locations. e.g: Photogrammetry does this– Can partially self-calibrate– Some DOF poorly determined

• What is the effect of calibration errors?– Effect is to introduce a scale error into displacement

measurements– Simulated a “minimal” calibration scenario:

“Calibration” = Where are these components located on their mounting plate?

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1mm uncertainty in component locations

0.3% scale error for vertical motion

Calibration Study

• What is the effect of calibration errors?– Effect is to introduce a scale error into displacement

measurements– Simulated a “minimal” calibration scenario:

– e.g vibrations with amplitude 1μm would be limited in reconstructed accuracy to 3nm from calibration

– a long-term shift of 100 μm would be limited in reconstructed accuracy to 300nm

“Calibration” = Where are these components located on their mounting plate?

Sh

inta

ke M

oni

tor

mo

un

ting

pla

te

QD

0

mo

un

ting

pla

te

1mm uncertainty in component locations

0.3% scale error for vertical motion

MONALISA at CLIC

• Start with 3 vertical lines– launch heads will be produced for KEK and CLIC by end of year– Need vertical tubes, ideally of 200 mm diameter

• Later add horizontal measurement – Need 200 mm horzontal tube– As much space at intersection as we can get.