Measurementofchargecollec1oninirradiatedminiaturesensorsfortheupgradeofATLASPhase-II

Striptracker

Vladimir Cindro Jožef Stefan Institute, Ljubljana, Slovenia

VladimirCindro,HSTD1110-15December2017,Okinawa,Japan

OnbehalfofITkcollaboraBon

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S.H.Abidi,A.A.Affolder,M.ArraBa,V.Cindro,B.Ciungu,K.DeKe,Z.Dolezal,C.Escobar,V.Fadeyev,C.Garcia,I.M.Gregor,K.Hara,L.B.A.Holmes,P.Kodys,G.Kramberger,J.Kroll,C.Lacasta,V.Latonova,D.Madaffari,I.Mandić,M.MikesBkova,M.Mikuž,M.Minano,

K.Nakamura,R.S.Orr,D.Rodriguez,E.Rossi,U.Soldevilla,J.Suzuki,R.Teuscher,Y.Unno,S.Wada

Outline

•  MoBvaBon•  IrradiaBons•  C/VandI/Vmeasurements•  CCEmeasurementswithAlibavasetup•  EdgeTCTmeasurements•  Conclusions

VladimirCindro,HSTD1110-15December2017,Okinawa,Japan 2

Fluences in ATLAS ITk: •  Strips:4barrellayersand6forwarddisks(165m2)40cm≤r≤100cm•  PeakinstantaneousluminosityuptoL=7.51034cm-2s-1(pile-up≈200)•  ThepredicBonsofparBclefluencesandionisingdosesfortheITklayoutassumean

integratedluminosityof3000i-1:•  Stripsensorswith75.5μmpitchinbarrelandrangingfrom69μmto85μmin

disks

Themaximum1MeVneutronequivalentfluencesforthebarrelandstripend-capdetectorsarepredictedtobe2.81014cm2and8.21014cm2,respecBvely.InaddiBonasafetyfactor1.5isrequired!Stripsatr>40cmèneutronshavethelargestcontribuBontotheNIEL!

VladimirCindro,HSTD1110-15December2017,Okinawa,Japan 3

VladimirCindro,HSTD1110-15December2017,Okinawa,Japan 4

Theminiaturesensorswithn-stripsinp-bulk:•  miniaturesensorsproducedbyHammamatsuonthesamehigh

resisBvityFZ6inchwafersasprototypesoffullsizeR0(thefirstringinATLASstripendcap)sensors(previouspresentaBon)

•  outerdimensionof10mm2x10mm2,≈325μmthick•  104readoutstrips,8mmlong•  threedifferentpitchestomatchthevariaBonofpitcheson"Stereo

Annulus“sensors•  75.5μm(default)•  70μm(narrow)•  84μm(wide)•  ACandDCcoupled

•  distributedtodifferentlabsforirradiaBons,electricaltestsandchargecollecBonmeasurements•  irradiaBonswithprotonsanddistribuBontolabs•  CV/IVmeasurements/Prague•  protonirradiatedCCEmeasurementsinJapanandValencia•  neutronirradiatedCCEandTCTmeasurementsinLjubljana•  distribuBonofwork:

Miniaturesensors:

pirrad CYRIC(Japan) nirrad Ljubljana C/VI/V Prague JapanCCEp Japan ValenciaCCEn,EdgeTCT Ljubljana

VladimirCindro,HSTD1110-15December2017,Okinawa,Japan 5

IrradiaBonswith70MeVprotonsatCYRIC(Japan):

•  temperature≈-15°C•  scanningwithsamplemovement•  irradiaBons≈1hr•  dosimetryusingAl27(p,3pn)Na24

spallaBonreacBon•  damagefactorfromRD50(1.47)•  equivalentfluenceuncertainty10%•  3fluences:5.6,11and22x1014neqcm-2•  storageinthefridgeawerirradiaBon

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IrradiaBonswithneutrons:

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

50.0

0 5 10 15 20 25

Tem

pera

ture

(C)

Time (min)

pt100_1

pt100_2

NTC

•  TRIGAreactoratJožefStefanInsBtute,Ljubljana

•  damagefactor≈0.90forfastneutrons•  irradiaBonflux≈1.61012neqcm-2s-1atfull

power(250kW)•  uncertaintyoffluences±10%•  equivalentfluences:5x1014,1015and2x

1015neqcm2

•  Approx.2hoursatRTbefore1stCCEmeasurement

TemperatureduringtheirradiaBon

Fluxperunitoflethargy(èlnE)indifferentexperimentalchannelsK.Ambrožičet.al.AppliedRadiatonandIsotopes130(2017)140-152

TotalLeakageCurrent:Pre-andpostprotonirradia1onATLAS12EC

non-irrad.

2.2E15neq/cm2

1.1E155.6E14

T=-20°C

T=+20°C

•  Smoothbehaviourupto600V/1000V•  Nobreakdownvoltageobservedinmeasuredinterval•  Leakagecurrentincreaseswithincreasingfluence

• Totalnumberofsensortested126:• ProtonIrradiaBons:Karlsruhe,Birmingham,CYRIC• Temperaturenormalizedto-15°C,I(T-15)=I(TM)*(T-15/TM)2*exp[-E/2kB*(1/T-15-1/TM)],withE=1.2eV• Sensorsannealed80minutesat60°C• Currentnormalizedto1cm2area;• AcBvearea-Innerdimensionofbiasring=>A(EC)=0.69cm2,A(barrel,A12EC)=0.637cm2

• Alfa(+20°C)=4e-17A/cm,temperaturecorrecBoncoefficientbetween+20°Cand-15°C:33

• LeakagecurrentsofnewA12EC(R0)sensorsareconsistentwithA12A,A12MandA07

Leakagecurrentpercm2ofprotonirradiatedmini’sComparisonA12A,A12M,A07andA12EC

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CVCharacteris1csforFullDeple1onVoltage(FDV)es1ma1on:Pre-andpostprotonirradia1onATLAS12EC–R0

Non-irradiatedsensors:•  FDV=280-290V(ρ=3.1kΩcm)•  CbulkatfulldepleBonis25pF

Irradiatedsensors:•  “FDV”increasedupto600Vat2.2e15neq/cm2

•  increaselowerthanexpectedfromgc=0.01cm-1≈1500V•  fluence

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CCEmeasurements(Alibavasetup)•  basedonanalogueBeetlechip•  25nspeakingBme•  40MHzclock•  90Srsource•  differentcoolingsystems(coldbox,PelBer)•  triggeringwithscinBllator•  samese�ngsofAlibavainalllabs(kazu.ini)•  normalizaBontoMIPMPV–23100e-hpairsin

300μmofdepletedunirradiatedsilicon(77pairs/μm)

90Srsource

holder

coolingblockphotomulBplier

Alsupportinthermalcontactwithcoolingblock

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Neutronirradiatedsensors–before(dashed)andawer(solid)annealing80minat60°C:

•  annealingincreasescharge•  nodifferencefordifferentpitchesandvoltagesbelow800V•  widerpitchgiveshighersignalbeforeannealingatthehighestfluenceandabove800V–indicaBonofmulBplicaBon•  thiseffectdisappearsawerannealing(decreaseofspacecharge)

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Longtermannealingat60°C:

•  shortterm-decreaseofspacechargeandtrappingimprovesCCEexceptatvoltagesabove1000VwheremulBplicaBondisappears•  longterm-mulBplicaBonathighervoltagesincreasescharge

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Fluencedependenceneutrons:

-  dashedline–beforeannealing-  solidlineawerannealing80minat60°C-  annealingimprovesCCEexceptatthe-  highestfluence-  Widerpitch–moremulBplicaBon!

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ComparisonwithA12:

R0ACdefsensorsfulllinesA12dashedlines

-A12(measuredin2014)

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Protonirradiatedsensors:

•  notannealedsamples-dashedlines•  annealedsamples-fulllines

•  80minannealingat60°Cincreasescollectedcharge

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Fluencedependence

•  protonscauselessdegradaBonofsignalthanneutronsatsameNIELfluence

•  @700Vsignalabove12keoinstripITk(withoutsafetyfactor)

•  @500Vsignalabove9keo

ITklargestfluence

EdgeTCTmeasurements:

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•  raiseofsignalèvelocity(Efield)profile•  integralofsignalèchargeprofile

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ComparisonR0–ATL12–beforeirradiaBon

ROsensorswerenotpolished!BothsensorshavesameacBvethickness–300μmResultsconsistentwithhigherresisBvity(lowerFDV)ofR0materialcomparedtoA12

Velocityprofile(belowdepleBon:) Chargeprofile(abovedepleBon)

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ComparisonR0–ATL12–awerirradiaBonwithneutrons:

Φ=51014ncm-2 è

ChargeprofileVelocity(Efield)profile

Φ=21015ncm-2

•  A12nominalresisBvity3.1kΩ,R0nominalresisBvity3.5kΩ•  A12andR0aremoresimilaratthehighestfluence–indicaBonofacceptorremoval

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Conclusions:

•  pitchvariaBondoesnotinfluencesignalupto800Vatallfluences

•  atthehighestfluencemulBplicaBonathighvoltages

•  widerpitchèmoremulBplicaBon

•  shorttermannealingimprovessignalatlowervoltages

•  protonscauselessdegradaBonofsignalthanneutrons

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Signal/Noise

MulBplicaBonincreasessignalfasterthannoiseValuesareforBeetlechip,shortstrips,lowtemperature!!