1

FP7 LEDPotential program to develop inertial sensors

Explore potential to achieve 0.1nm stability scale for the FD above a few Herz

A.Jeremie, C.Hauviller

2

2) Potential programme to develop inertial sensors. (Claude+Andrea) :

a) State of the art. b) Current limitations that need to be addressed to achieve 1nm above 1Hz and 0.1nm above 5Hz. c) Potential means to overcome these limitations. d) A rough idea of a potential schedule. It would be useful to keep in mind that we would like to use the sensors in the project. e) Resources needs and availability.

4) Potential programme to develop the software for the design of the module and to control the feedback. (Andrea)

3

State of the art inertial sensors

NI PCI-6052 Multifunction DAQ

Fast card Low noise card Compatible Matlab/Simulink (Softwares used for the algorithm)

nm stabilisation equipment exists

4

Feedback output: Actuator at the fixed-

part of the beam

State of the art inertial sensors

Free-fixed configuration close to the detector

5

« Passive » rubber:

- Enhance the perturbation around a given frequency fc

- Damp perturbations above fc

« Active » :- Active isolation in the frequency range enhanced by the passive material

Transfer function for passive material

frequency

fc

TMC Isolator

=>start building a prototype combining Passive and Active isolation

6

Electrochemical motion sensor

• Special electrolytic solution

• Four platinum mesh electrodes ( 2 anodes and 2 cathodes )

• An external acceleration creates a differential pressure across the channel and forces the liquid to move with velocity V. Ions move to the electrodes .

SP500 sensors from EENTEC• 0.0167 to 75 Hz

• Non magnetic

• 20KV/(m/s)very sensitive!!

IntroductionHigh frequency sensor VE13

Low frequency sensors

1 Tesla testing

PMD scientific has promised to send us 2 prototypes; conditions not yet finalised => work together on sensor development

7

Spring

Cantilever

Electrodes, Test Mass

RF IN

RF Out

SLAC sensor development with Joe Frisch

• BeCu spring (high tensile strength, non magnetic): Pre-bent; Simulation of creep fluctuations indicate <1 nm noise

• Thermal effects very large!! ~10-8 C corresponds to (0.1Hz) noise limit• Eddy currents from variations in solenoid field produce non-negligible

eddy current forces on these conductors

8

Inertial Sensor Development

• Develop in lab a new sensor as SLAC did: not us! We don’t have the necessary resources for that at LAPP!

Would need an electrical/instrumentation engineer for that

• Keep an eye on commercial developments and contact companies:-sensors: PMD scientific, PCB scientific-actuators: Cedrat and PI

=>Milestones: over the whole period of program =>Human resources: PhD? for 3 years plus supervisor (50%?)=>Financial resources: 2 sensors/year: between 4000-20000 euros each

actuators: 1000 euros each

9

FD stability

Things we don’t know:

What is the FD configuration? Saclay?Is it normal or superconducting? (M.Aleksa’s work: Sm2Co17)How close to detector? MDI issues=> free-fixed or fixed-fixed configuration?What is needed for CTF3 test: in preliminary proposal text it is said that a mechanical equivalent could be used…FD issues not for CTF3?

2 pieds 23 41,543 pieds 62,38 79,834 pieds 119,33 133,565 pieds 191,63 213,073200200 900 1700 2500

500 1700 3000300 1300 2200 3200

répartition des pieds en mm Premières fréquences en Hz800 2700

Needed for a test:

-FD (real or mock)-support (what configuration?)-sensors/actuators-feedback loop (see next presentation)

10

Reflections on FD stability for ATF2 (B.Bolzon):

•Beam repetition rate: 1Hz at beginning=>beam-based feedback 0-0.1Hz (at best!)•CLIC Stacis 2000 table works best between 1-50Hz=> even amplifies vibrations below 1Hz!•Rigid mount preferred to have coherent movement with Beam-Rigid mount preferred to have coherent movement with Beam-shape Monitor (Shintake)shape Monitor (Shintake)•CLIC Stacis 2000 block in free floating configuration (250Hz), but in fixed configuration (60Hz). Still OK.

11

LHC Low ß LHC Low ß QuadrupoleQuadrupole

Vessel socket vs jack base

• the transverse mode structure already visible at the interface between the jack and the concrete pad, but not in the floor• the enlarged contact surface produces significant benefits on the dynamic stability of the module

Effect of the support foundationEffect of the support foundation

Vessel socket vs floor

the results of the measurements on this short quadrupole cryostat look promising for the use of the alignment jacks for the ILC linacs, after suitable modifications

R.Amirikas, A.Bertolini

12

Resources needed

Human resources:Mechanical engineer for design of support from Europe: 36 monthsMachine shop: 6 monthsAutomatics engineer (see next presentation)Sensor and actuator, MDI study: PhD? together with module support?

Material resources:dedicated sensors: between 4000-20000 euros eachactuators: 1000 euros eachmaterial for support construction: 10000 euros

Milestones:the two-beam scheme being the main subject to demonstrate for 2009/2010, the FD stability can go over the 5 years of the program.

=>construction of test stand until 2009 with specifications well understood=>tests during 2009/2010