XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 1/24 Optical fibre sensors for environmental
monitoring at LHC and SLHC experiments Fibre Optical Sensors (FOS)
applications Fibre Bragg Grating FOS (FBG) specificities First FBG
applications in HEP: T and measurements in CMS New R&D line:
FBG as Relative Humidity sensors Polyimide coated FBG as RH
sensors: experimental results N. Beni ( ATOMKI / CERN ); G. Breglio
( Federico II / Optosmart ); S. Buontempo ( INFN Napoli / CERN );
M. Consales ( Sannio ); A. Cusano ( Sannio / Optosmart ); A. Cutolo
( Sannio / Optosmart ); M. Giordano ( CNR Napoli / Optosmart ); P.
Petagna ( CERN ); Z. Skillasi ( ATOMKI / CERN )
Slide 2
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 2/24 Multipoint distributed sensor through
fibre grating Concept of Fibre Optical Sensor (FOS) - B [nm]
Reflectivity External medium Sensitive layer Single-mode optical
fiber P out =kR Film P in k is a constant R Film is the film
reflectance R film =f ( Film, d Film, ext ) Film is the complex
dielectric constant of the film d Film is the film thickness ext is
the external medium dielectric constant Single point sensor through
fibre tip coating
Slide 3
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 3/24 Main advantages of FOS technology For a
large number of environmental monitoring and industrial
applications fiber-optic sensor technology now offers several
advantages for significant metrological improvement through:
Immunity to electromagnetic interference Lightweight Possibility to
work in hard environments Intrinsic Radiation Hardness High
sensitivity, versatility and bandwidth Simple multiplexing Absence
of electronic circuitry in the measurement area This technology is
suitable for remote measurements and it is, by definition,
compatible with the fiber-optic communication networks
Slide 4
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 4/24 FOS fields of application Measured
parameters: Strain Temperature Vibration Refractive index Chemical
detection Humidity Electric and Magnetic field Integration with:
Metal oxide particle layers Nanoporous Polymers Carbon nanotubes 1
0.1 C Up to 1 MHz 10 -5 < 1 ppm < 1% Bandgap engineering
Microstructuration Tapering Application to: Structural health
monitoring Damage detection Aeronautic monitoring Geodetical
monitoring Enviromental monitoring Acoustic monitoring Railways
monitoring Photonic devices Micro-structured Fiber Gratings Tapered
Fiber Hollow core optical fiber Micro resonators Long period Fiber
Gratings
Slide 5
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 5/24 Examples of industrial applications
Slide 6
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 6/24 Fibre Bragg Grating FOS Reflected signal
Transmitted signal Cladding Core Source LED Where: n eff is the
effective refractive index of the fibre is the grating pitch B is
the reflected Bragg wavelength Any strain or temperature
perturbation experienced by the FBG results in a Bragg wavelength
shift 1, 2, n 1 2, n 1 /2n eff
Slide 7
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 7/24 Why FBG Sensors?
Slide 8
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 8/24 First use of FBG sensors in HEP: CMS ~
100 T or sensors placed in the following areas in CMS: HF region
negative side (Raiser and Castor table) Tracker bulkhead on both
sides (10-10 sensor) Experimental Cavern (60) ( in January 2011)
(in 2009) Aim: demonstrate feasibility follow mechanical changes
induced by magnetic field (HF-) Monitor the T distribution in front
of the Tracker (2011) monitor the cavern environment In the last
two years the CMS experiment at LHC accepted to pioneer the
application of FOS (FBG) to an HEP experiment
Slide 9
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 9/24 measurement during 2011 magnet ramp-up
Near side Far side
Slide 10
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 10/24 T distribution in front of the Tracker
Z- Z+ One year record of temperature measured by FBG follows the
activity of Tracker and provide information on the thermal mapping
of the critical area between the TK and the EE
Slide 11
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 11/24 Additional FBG to map T in the cavern
19.6 19.5 18.7---19.2 18.7 19.319.820.019.619.2 19.9
19.119.520.020.119.8 19.119.921.720.3 Z+Z- 19.519.719.4 19.2
---19.219.3 ---19.219.920.019.8 19.519.619.819.218.9
19.219.921.820.3 Z-Z+ Additional 60 FBG T sensors has been
installed in the experimental cavern in January 2011 : - 23 sensors
on wall near side - 3 sensors on ceiling +Z side - 23 sensors on
wall far side - 8 sensors on shaft far side - 3 sensors on ceiling
-Z side Some HOURS of work to install all of them! In the figures a
snapshot of the T distribution on the rack balconies is shown
Slide 12
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 12/24 A curiosity about T distribution in the
shaft 16.4 16.6 16.9 16.8 17.1 17.5 18.6 Shaft plug closed Shaft
FBGs are installed Daily temperature peak of the top sensor
appearing when shaft plug is open (every day a bit later than the
previous one): effect of direct sunlight discriminated surface
cavern
Slide 13
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 13/24 Humidity sensing issues in HEP Trackers
HUMIDITY SENSOR SPECIFICATIONS FOR HEP TRACKING DETECTORS Low mass
Small dimensions Insensitivity to magnetic field Operation at
temperature down to -40 C Response to the full range [0, 100]% RH
Reduced number of wires needed Radiation resistance to doses up to
1 MGy HIH 4000 series by Honeywell Small Inexpencive 3 wires for
each measuring point Accuracy of 3,5%RH Response time 15s Minimum
operation temperature -40C Not radiation resistant!!! CURRENTLY AT
CERN (typical)
Slide 14
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 14/24 Almost all miniaturized humidity sensors
presently available on the market are electronic sensors (mainly
capacitive-based, followed by resistive-based). Despite all
efforts, these sensors still fail to provide a complete set of
favourable characteristics, e.g., good linearity, high sensitivity,
low uncertainty, low hysteresis and rapid response time. For an
application in HEP detectors, one should add to this the
sensitivity to electro-magnetic noise pick-up, the suitability for
multi-point distributed measurements and the resistance to ionizing
radiations. Motivations for R&D on new RH sensors Nowadays
although important requirements on environmental control exist, in
particular for Trackers there is no miniaturized humidity sensor on
the market well suited for HEP detector applications
Slide 15
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 15/24 FBG as relative humidity sensor Bare FBG
is insensitive to humidity. Use of sensitive material as coating of
the FBG to induce a mechanical effect. Hygroscopic polymers swell
upon adsorption of water molecules. Sensing principle Absorbtion of
moisture by the polymeric coating Expansion of the coating
(swelling) Strain induced on the FBG Bragg wavelength shift
Realization of humidity sensor by coating the gratings with a
suited polymer. POLYIMIDE COATING FBG2 RH SENSOR FBG1 T- SENSOR
Temperature compensation is needed
Slide 16
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 16/24 Starting point: polyimide coating 2002
2005 Relative humidity range limited to 10 90 % RH Temperature
range limited to 10 65 C Completely unexplored effect of ionizing
radiations
Slide 17
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 17/24 RH testing / calibration facility @ CERN
Test section Thermally controlled liner Salt solution container (if
needed) External air circulation (dry + saturated air mixer) Closed
loop circulation (salt solution in box) Chilled mirror Ranges: 0%
RH 100% -20 C T +30 C Insulated confinement
Slide 18
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 18/24 Optoelectronic interrogation system
Slide 19
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 19/24 Custom fabricated polyimide coated FBG
Naked FBG outsourced under strict specifications In-house multiple
dip coating + oven curing cycles with PI2525 HD Microsystem Pyralin
Family 1 (thin): coating thickness = 8 mFamily 2 (thick): coating
thickness = 17 m
Slide 20
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 20/24 Low temperature & humidity
properties Family 1 (thin): coating thickness = 8 m (typical)
Family 2 (thick): coating thickness = 17 m (typical) S RH =0.42
pm/%RH7,.% S T =9.54 pm/C0.9% Temperature sensitivity: Humidity
sensitivity: S RH =2.09 pm/%RH19.6% S T =10.08 pm/C12.4%
Temperature sensitivity: Humidity sensitivity: NOTE: Time response
very (too?) slow at T < 0 C
Slide 21
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 21/24 First ionizing irradiation dose: 10 kGy
Family 1 (thin): coating thickness = 8 m Family 2 (thick): coating
thickness = 17 m Perfect peak invariance after first irradiation
Note: Honeywell HIH 4000 dies (no signal) after 10 kGy ionizing
irradiation dose
Slide 22
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 22/24 Further irradiation level: 50 kGy T = 20
C: before and after irradiation T = 0 C: before and after
irradiation -irradiation tests up to 50 kGy* show good radiation
resistance and suggest no further variation after the first level
(possibility of applying a pre-stress) * latest data at 100 kGy
confirm the observation
Slide 23
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 23/24 More technical details and results?
Relative Humidity Monitoring by Polyimide-Coated Fiber Bragg
Grating Sensors for High-Energy Physics Applications Accepted to
IEEE Sensors 2011 (Limerick-Ireland)
Slide 24
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 24/24 Further developments Continue
irradiation studies up to 1 MGy Perform tests at intermediate T
(accurate T dependence estimate) Accurate measurement of response
time in function of T Develop reliable packaging for field
operation Study different kind of polymeric coatings (epoxies?)
Feasibility of different gratings for direct humidity reading (LPG)
Create a real network among all FOS developments suited for HEP (
Full scale cryogenic thermometers, Magnetic field measurement,
Dosimeters, CFRP and Silicon embedded strain measurement, )
Resubmission of the FOS4HEP MC ITN proposal ONGOING 2012
FUTURE
Slide 25
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 25/24 (RESERVE SLIDES FOLLOW) THANK YOU FOR
YOUR ATTENTION!
Slide 26
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 26/24 RESERVE: and T discrimination in
FBG
Slide 27
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 27/24 RESERVE: and T discrimination in
FBG
Slide 28
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 28/24 RESERVE: and T discrimination in
FBG
Slide 29
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 29/24 RESERVE: and T discrimination in
FBG
Slide 30
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 30/24 RESERVE: and T discrimination in
FBG
Slide 31
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 31/24 RESERVE: FBG interrogation
Slide 32
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 32/24 RESERVE: FBG interrogation
Slide 33
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 33/24 RESERVE: FBG interrogation
Slide 34
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 34/24 RESERVE: FBG interrogation
Slide 35
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 35/24 RESERVE: FBG interrogation
Slide 36
XXIII International Symposium on Nuclear Electronics &
Computing Bulgaria, Varna, 12-19 September, 2011 Optical fibre
sensors for environmental monitoring at LHC and SLHC experiments -
Paolo Petagna (CERN) 36/24 RESERVE: FBG interrogation