napoli, 17 settembre 2012 salvatore buontempo infn napoli on behalf of the fos4cms group cnr napoli...

Napoli, 17 Settembre 2012

Sensori a Fibre Ottiche nell'apparato sperimentale CMS

al CERNSalvatore Buontempo

INFN Napoli

on behalf of the FOS4CMS Group

CNR Napoli

Uni SannioBenevento

Uni Federico II Napoli

ATOMKIDebrecen (Ungheria)

NIKIETMosca(Russia)

OptoSmartNapoli

CERNGinevra(Svizzera)

Napoli, 17 Settembre 2012 2

FOS and CMS/HEP

Fiber Optic SensorCommunity(academic and

industrial partners)

SIF XCVIII Congresso Nazionale

CMS Collaboration @ CERN

FOS4CMS Group

FOS4HEP Project


Outline• FBG concept

• Overview of FOS sensors in CMS

• FOS Infrastructure in CMS

• Temperature measurements in CMS with FOS Silicon Tracker Bulkheads CMS Underground cavern (UXCsite) Cathod Strip Chamber (CSC-ME4/1) Pixel Luminosity Telescope (PLT)

• Strain measurements in CMS with FOS• Hadron Forward Calorimeter support

• Additional CMS T and strain FOS installations planned in 2013 LS1 • T on RPC Forward• Strain on YE4 disk• T and Strain on new central Beam Pipe

• Development of new sensors for HEP based on FBG technique(FOS4HEP)

• Relative Humidity• T and Strain Measurement in Cryogenic environment



Fiber Bragg Grating (FBG) Concept

4

effB n2

Where:neff is the effective refractive index of the fiber,

Λ is the grating pitch and

λB is the reflected Bragg wavelength.

TEMPERATURE CHANGE

Thermal expansion for Termo-optic effect for

STRESS

Elasto-optic effect forDirect Strain for

effn

effn




5

Temperature Sensitivity ≈10pm/°K

@ λB=1550nm

T

STRAIN AND TEMPERATURE Sensitivity : FBG Spectral Response (Temperature)

FBG SPECTRAL RESPONSE: Temperature Shift




6

STRAIN AND TEMPERATURE Sensitivity: FBG Spectral Response (Axial Strain)

FBG SPECTRAL RESPONSE: Axial Strain Shift

Strain Sensitivity ≈1pm/με

@ λB=1550nm

ε



The Compact Muon Solenoid (CMS) experiment in CERN P5 site (Cessy - France)


FOS Sensors in CMS

• Sensors placed to the following areas in CMS (133 sensors):– HF region negative side (Raiser and Castor table 10 + 6 sensors)– Tracker bulkhead on both side (10 +10 sensor)– Experimental Cavern (60 sensors) in January 2011– PLT T-sensors (13 sensors) 2012– T/RH tests in the cavern/cooling plants, (12+12 sensors) 2012

in 2009

Aim:

• demonstrate feasibility in very hostile environment

• monitor mechanical deformations induced by field (HF-)

• monitor T in detector and in the environment



FOS infrastructure in CMS site

• A backbone of 72 fibers was installed between X1 near and S2C18

• New patchpanel is added to S2C18 • New 1U 16 channel interrogator in the

system


Service Cavern (USC)70 m underground

Detector Cavern (UXC)100 m underground

120 m fiber lenght distance

Second interrogator for additional 16ch being installed in these days

CMS today can read up to 2000 FBGs !


Temperature sensors on the Silicon Tracker Bulkheads



Position of BulkHead Temperature sensors

Positive side:


Goal:• check the T distribution on

bulkheadand along the cable tray • Compare T distribution before

(FOS) and after (electronic sensors) bulkhead


Position of BulkHead Temperature sensors

Negative side:


20 sensors installed in July 2009.

Installation time: 4 hoursAdditional cables: 1 fiber split in two to reach positive and negative bulkheads


2012 data


• 20 sensors running without any problem since July 2009 24h, 7/7. Only pause is due to Maintenance Winter shutdown (25 days in January).

• High radiation dose: no effect of LHC ON/OFF, no aging detected so far• High Magnetic Field (3.8T): no effect of B field ON/OFF • No interference with other subdetectors and electronics close by


Comparison of FOS and Tracker sensors



Temperature sensors in the UXC cavern



Additional T sensors in UXC

16

• Additional 60 FBG T sensors were installed in 2011 in UXC,positioning a single fiber (2km long ) in 3 days:

- 23 sensors on wall near side- 3 sensors on wall +Z side- 23 sensors on wall far side- 8 sensors on shaft far side- 3 sensors on wall -Z side

FOS operation in CMS


Shalf - far side

17

16.4

16.4

16.6

16.9

16.8

17.1

17.5

18.6

All values in °C



UXC T monitoring in CMS control room panel



Temperatures in 2012

YB0 YB Gap-3YB Gap+3

Shaft

X0

Far Side on Balcony

Near Side on Balcony

HF+ HF-

Top of shaft feels the summer…

-END

+END



Temperatures in Shalft open

Shaft


Shalf open

zoomzoom

zoom

Happens at the same time (every day a bit later than before): Direct sunlight effect on top shaft sensor S7 !

S7

S8

S6

S5

S4

S3

S2

S1


Temperature sensors on Cathod Strip Chamber (ME+4/1)



ME+4/1 temperatures

Goal:measure T on electronic frame

(not cooled and cooled areas) vs the beam collision rate


Very fast Installation :1h to install a Y splitter one of

existing fiber and put 2 new T sensors on the new fiber


ME+4/1 temperatures

Result : No T effect on CSC electronics induced by beam on/off nor by beam interaction rate



PLT (Pixel Luminosity Telescope) Temperature measurements



T on PLT

~ 10 cm


Goal:Monitor T on PLT electronic card vs beam collision intensityin an independent mode.

LHC pipe

FBG installation VERY close to LHC beam pipe, in a very forward region(very high radiation dose mostly due to non ionising particles)


Parasitic use of esisting DAQ optical links

No additional FOS clear fibers were installed in the PLT Zone

Instead of installing a new monomode clear fiber dedicated for FOS, we tried to use a spare PLT DAQ existing optical link

PLT link goes directly to USC, therefore only a short patch cable had to be installed in USC between the PLT and FOS racks

In addition FC/APC connectors had to be changed to MU (only MPO-MU fanouts are accessible)



T on PLTNear Side(Array1)

Array could be installed without any problem.


Spectrum is as clear as it was read out close by interrogator PLT monitor in CMS control room


PLT hybrid temperatures



PLT hybrid temperatures in 2012

• ~2 degC T drift since march (beam ON)• On/off status has no effect on T drift• Cavern T looks quite stable• PLT warms up?• Any other effect? ... Still under evaluation



Strain measurements on Forward Hadronic Calorimeter



Position of CASTOR Platform sensors


Castor detectordismounted in Dec 2011

Monitor the mechanical effect


Position of sensors on the Raiser


IP side(positive)

Not IP side(negative)


End 2011-2012 dataset – Raiser

La

st r

am

p d

ow

n in

20

11

La

st r

am

p d

ow

n in

20

11

Fir

st

ram

p u

p i

n M

arc

h

Fir

st

ram

p u

p i

n M

arc

h



10/2011-2012 dataset – Green Platform

La

st r

am

p d

ow

n in

20

11

Fir

st

ram

p u

p i

n M

arc

h

• Lower and upper sensors behave different with (2011) and without (2012) Castor Detector



Ramp up — Raisers non IP side

Near side Far side(grey lines: last two rampups in 2011)


B field result: simmetric Extension effect on both sidesVery visible effect of CASTOR removal


Near side Far side

Ramp up — Raisers IP sideVery visible effect of CASTOR removal

(grey lines: last two rampups in 2011)

(grey lines: last two rampups in 2011)SIF XCVIII Congresso Nazionale

B field result: simmetric Compression effect on both sides


Ramp up — Green platform

Near side Far side(grey lines: last two rampups in 2011)


Very visible effect of CASTOR removalon UP sensors


Ramp down — Raisers non IP side

Near side Far side(grey lines: last three rampdowns in 2011)


Visible effect of CASTOR removal


Near side Far side

Ramp down — Raisers IP side

Visible effect of CASTOR removal

(grey lines: last three rampdowns in 2011)

Fast dump (green line) did not diverge from the slow dump behavior



Ramp down — Green platform

Near side Far side(grey lines: last three rampdowns in 2011)


Very visible effect of CASTOR removalon UP sensors


0mm

compression

extension

displacement

Strainε~80 µm/m Strain

ε~ -50 µm/m

0mm

13 (10) mm

Rear ofCASTOR

BPSupport13,36m

0.5÷1.5mm5mm (4.5mm)

13mm

@ 3.8T

1.5mm


Strain Monitoring : Green Platform vs B field

S


Strain Monitoring : Green Platform vs B field

In the conditions without B fieldthe calculations done using FOS datacorrespond to those done withPrevious ANSYS analysis.

In B field conditions FOS data are theonly source of info about real force induced by B field.

B field simulations are available butit is very difficult to include all the effectsof present metallic structure.


Conclusion: the Collar Platform and the Table are strong enough; all displacement of ForwardZone depends on raiser tower deformation only.

Fibers on the Collar Platform and on the Table

S5;S6;S7;S8T3

S2

S1;S2;S3;S4T1;T2

S1S3

S4

Strainε~50 µm/m


CMS survey report confirmed the displacements

@ 3.8T

1.9mm1.3mm

-1.4mm

4.4mm

Data by Joao Antunes


Additional CMS T and strain FOS installations planned in 2013 LS1



Temperature sensors on RE4



T measurement on RPC endcap disks

1.4m 1.0m

2.0m


Goal: monitor T on RPC strips for each of 72 detector chambers in a disk endcap


RPC FOS Array Layout2 independent arrays:Array R2: 36 FOS 1.4m distant each,

tails 8m each with connectors on both ends

Array R3: 36 FOS 1.8m distance each,tails 6m each with connectors on both ends

Lambda distribution in each array should allow to have 72 picks (36 R2 + 36 R3) uniformly distributed in 80 nm bandwidth (to be checked)

On each array :Max attenuation on sensor n.36 (last) is 10 dB

On arrayR2+array R3 in serial mode: Max attenuation on sensor n.72 (last) is 20 dB

No magnetic element in FOS packaging and splicing.

1.4m1.0m

2.0m Array R2

Array R3



Installation Layout

Two arrays installed on each disk with both connectors on the near side rack panel (4 connectors on each disk)

4 clear fibers + 2 spare to be positioned from each disk up to disk 1 rack panel = 18 fibers for each endcap (all in near side passing in mini cable chain)

18 + 18 = 36 clear fibers to be positioned from disk 1 up to CMS FOS patch panel in X1. Path being discussed with Integration Office.

CMS FOS RackDisk 1

RE2RE3

RE4


In total: additional 72x6= 432 T sensors to be installed and read out


Strain on YE4 disk



YE4 shielding disk

Strain sensors on the YE4 disk (2x18 sensors)

to monitor deformations induced by B field



Strain and T on new CMScentral beam pipe



New CMS Beam Pipe

• Strain and Temperature sensors along the new beampipe (4x10 sensors)• We intend to monitor the sag with strain sensors on top and bottom of pipe• We will monitor the T distribution along the beam pipe• Very high radiation dose



Development of New Sensors for HEP based on FBG technique

(FOS4HEP)



Cladding Core

Bragg Grating

Buffer

FBG sensor


Coating Material


By using a functionalized coating material,i.e. mechanically sensible to the variationsof the parameter to monitor


Relative Humidity sensors for CMS Tracker



NEEDS AND REQUIREMENTS FROM CERNFOR RELATIVE HUMIDITY SENSORS

• 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 • Reliable reading across long distances

• High long term stability and/or possibility of an easy remote recalibration• Radiation resistance to dose up to 1 Mgy

CapacitiveSmall Size

Inexpensive3 wires for each RH measuring point

Accuracy of 3,5%RHResponse time 15s

Minimum operation temperature -40°CNOT Radiation hard

HIH 4000 series by HoneywellMiniaturized humidity sensors used at CERN

Precon HS2000 Hygrometrix HMXCapacitiveSmall SizeEasy in use

Direct reading of Dew PointNOT radiation hard

Sensitive to B fields

Resistive Small size

Tolerant to radiationsExtremely low response

Complex chain of read-out over long distances

Highly not linear signalNOT AVAILABLE on the market any more

OUR SOLUTION: Fiber Optic Sensors based on FBG

technology • Multiplexing capability (Reduction of cabling complexity) • Radiation hardness capability



..Use of FBG as RH sensor is not new in literature..

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 polyimide film

• Bare FBG is insensitive to humidity.

• Use of sensitive material as coating of the FBG to induce a mechanical effect

Sensing principle

RHSTSRHTfmeasured RHTB %),(_

POLYIMIDE COATING

FBG2 coatedRH SENSOR

FBG1 uncoatedT- SENSOR

Temperature compensation is needed RH SENSOR COUPLED TO T SENSOR

TBmeasuredBRHB ___ Lambda variation only due to RH variations


Calibrations of FOS-RH sensors

RH-FOS’s readings very compatible to SHT15_RH!!

Calibration based on the data provided by the analogic reference sensors

(SHT15_RH)

0 500000 1000000 1500000 2000000 2500000 3000000 3500000 4000000

15

20

25

30

35

40

45

50

55

60

65

70

RH

(%)

t(sec)

F6_RH_1 cal based on SHT15 F6_RH_2 cal based on SHT15 F6_RH_3 cal based on SHT15 F6_RH_4 cal based on SHT15 SHT15

1) RH tests in climatic chambers (controlled in temperature)2) Installation of 3 boxes with RH FOS in CMS site (cooling plant)We are presently working on the calibrations of 80 RH FOS sensors• RH FOS are providing VERY good results in first real environment application

in CMS UXC site• If correctly calibrated they are reproducing quite well data from reference

sensors, but they are radiation hard !!

E.g. Calibration of Array F6-RH-1_4 in BOX A



Additional CERN FOS projects triggered by FOS4CMS group

(for more detail see also Prof. L. Rossi talk tomorrow)



CRYO Temperature sensors

a base material with a large thermal expansion coefficient

at cryogenic temperature needs to be selected

FBG sensitivity 8 - 12 pm/K @ room T< 0.1 pm/K below 40 K

0 50 100 150 200 250 300-25

-20

-15

-10

-5

0

Temperature [K]

Wav

eleng

th sh

ift [n

m]

warm up Teflon

warm up PMMA2warm up PMMA1

Potential use of FOS for temperature monitoring• in very extreme value ranges (max. 700 °C and min 1.9 K)

• with high precision and fast response (aim to locate rapidly possible hot spot)

• over long distances: Superconducting links (power transmission cables to be cooled with Helium gas up to 20 K between the LHC tunnel and the surface)

Reduction of instrumentation and improvement of workplace safety in the

upgraded tunnel

Polymers are the best candidates


CRYO Strain sensors

• To monitor the strain and the strain distribution of the coils and of the magnet structure during assembly, cool down, powering and warm up

• To monitor the strain variation during assembly, cool down powering and warm up

• To detect quenches

Low heat in-leak into the bath and less wires needed in comparison with the standard strain

gauges

Temperature and stress profile from winding to operation for new generation

SC magnets: challenge for Nb3Sn materials that is STRAIN SENSITIVE

FBG sensors and strain gauges glued on the Aluminum shell of the magnet

Quench monitoring

Potential use of FOS for strain


Additional fields of interest

for FOS technique:We have a clear expression of interest from CMS Collaboration

for additional application of fiber sensors for:

• Magnetic field measurement

• Gas detection

• Vibration monitoring

• Radiation monitoring / Dosimetry



Conclusions• FOS4CMS project started in 2009 and is rapidly expanding year by year

At present we have about 150 sensor running without ANY problem since 3 years

24h, 7/7, T and strain monitoring in hostile environment without any problem We have installed a facility ready to handle 32 fibers (about 2000 sensors) fully

compatible with CERN software standard We have already received requests for additional 700 sensors to be installed in

next year of maintenance/upgrade (RPC, YE4, new beam pipe, tracker)

• R&D on new fields of application of FBG technique with custom coating are giving

very positive and interesting results Relative Humidity sensors for low range and high precision have been produced

in mass scale (100 pieces). Reliability is impressive. Calibration on goin.

Intallation in March 2013 in CMS Tracker. First prototypes for Cryo T and Cryo Strain are both giving very positive results

(see Prof. L. Rossi talk tomorrow onLHC upgrade)

• Additional requests from CMS and HEP for new fields of application of FOS technique



Conclusions

Optical Fiber Sensor Technology is becoming a new

reference standard in CMS and in HEP

Great example of interdisciplinary collaboration

between academic and industrial partners

FOS validation and impressive stable/reliable

results in very hostile environment (high radiation

and high electromagnetic field) will open more field

of application for technology transferSIF XCVIII Congresso Nazionale

napoli, 17 settembre 2012 salvatore buontempo infn napoli on behalf of the fos4cms group cnr napoli...

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