Depfet Evo meeting. D. Moya IFCA (CSIC-UC) FOS based displacement sensors for PXD-SVD movements measurements.

_Outline — Omegas layout. — Calibration set-up — Calibration results — Compare simulation/experimental results — Outlook D. Moya, Depfet evo meeting, January. 17th 20122

_Development of FOS based displacement sensors 3D. Moya, Depfet evo meeting, January. 17th 2012  Design a transducer to allow us to transform FBGs strain in displacement (FBG-s embedded in an special geometry composite structure (omega)  Some designs done for PXD-SVD ( with integration problems, news?)  After first mechanical dummies manufactured, first omega prototype ( with FBG embedded) has been manufactured at INTA.  The decided design was the first proposed ( 20 mm length mechanical dummies)  Two different layout ( only with carbon fiber layers and with Glass fiber layers)  Unidirectional carbon fiber / glass fiber fabric manufactured first

_Development of FOS based displacement sensors 4D. Moya, Depfet evo meeting, January. 17th 2012  First omega prototype manufactured with three FBG sensors embedded: FBG sensors Fibers ingress Fibers egress  Two sensors are positioned in the outer and inner layer of the omega (point of maximum strain / maximum resolution)  One sensor in the middle layer to compensate temperature (point of minimum strain)  The temperature can be compensated with the difference in the measurement of bottom and top sensor)

Micrometric Stage _Development of FOS based displacement sensors 5D. Moya, Depfet evo meeting, January. 17th 2012  The omega has been calibrated using a micrometric stage OmegaFBG sensor interrogation unit

_Omega First measurements 6D. Moya, Depfet evo meeting, January. 17th 2012  The omega has been calibrated using a micrometric stage Time ¼ s Botton Top Mid. Temp. Wavelength change nm Temperature ºC

_Omega First measurements 7D. Moya, Depfet evo meeting, January. 17th 2012  The obtained displacement resolution is about 1 um  The relation is lineal in the range +1mm to -1 mm  The temperature can be compensated by difference between the top and bottom sensor  The omega will be tested in Santander again to measure the reaction and have redundancy in the results obtained.

_Temperature sensitivity 8D. Moya, Depfet evo meeting, January. 17th 2012  Measurements to different temperatures  The sensibility of the omega to temperature is very low  The temperature compensation must be studied in more detail

_Simulation/Experimental results 9D. Moya, Depfet evo meeting, January. 17th 2012  Good agreement between experimental and simulation results  Difference could be explained by a different position of the fiber inside the layout Displacement (mm) Bragg wavelength Shift (pm)

Summary 10D. Moya, Depfet evo meeting, January. 17th 2012  First omega prototype manufactured  Has been calibrated to different temperatures  Good intrinsic resolution (about 1 micron), BUT final accuracy limited by systematic effects (study of self- conpensating temperature algorithm, still on going) and linear range ( ±1mm)  Next Steps  Study in more detail temperature compensation  Recalibrate at IFCA ( measure strain-displacement-reaction at different humidity and temperature conditions)  Radiation hardness and sensitivity will be studied during the next months