Neutron Damage of Camila Pazos - bndhep.net · BRANDEIS UNIVERSITY -Camila Pazos 0 0.002 0.004...

NeutronDamageofCCDsinATLASEndcap

CamilaPazosBrandeisUniversityJ.Bensinger, K.Hashemi,L.Simpson, R.Studley

RadSimWGMeetingMay21,2019

CCDsintheATLASendcapalignmentsystemcanexperienceabuildupofchargeinpixelsfromthermallygeneratedelectrons,calleddarkcurrent,causedbyneutrondamage.

WemeasurethedarkcurrentintheATLASCCDsandmodeltherelationshipbetweendarkcurrentandneutrondosewiththeequation

I = α D e(T−20°C)/(12°C) counts/px/mswhere,I isdarkcurrentincountsperpixelpermillisecondD istheneutrondosein1012 1-MeVNEcm-2 (Tn)T istemperatureincentigradeα isarateconstantthatdescribesthedarkcurrentgeneratedperneutrondose incounts/px/ms/Tn

Measurementsoftheamountofdarkcurrentinoursystemcouldbeusedasmeasureofneutronflux.

AlignmentSystem&CCDs

BRANDEISUNIVERSITY- CamilaPazos 221-May-19

3

Pre-ProductionExperiments

LowellExperiment:• In1998,fourTC255PCCDheadsweresubjectedtovaryingneutrondoses(between2.0Tnand8.0Tn)over9hourswithaneutronsourceatUniversityofMassachusettsatLowell.

PROSPEROExperiment:• Thefollowingyear,8TC255PCCDheadsweresenttothePROSPEROreactorinFrance.Theyreceivedneutrondosesbetween0.5Tnand10.0Tn.

BRANDEISUNIVERSITY- CamilaPazos

I = 0.28 D e(T−20°C)/(12°C) counts/px/ms

I = 0.26 D e(T−20°C)/(12°C) counts/px/ms

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NeutronDamageinATLAS

DataSetInformation• ImageswerecapturedwitheachCCDandanalyzedtofinddarkcurrentduetoneutrondamage.• Eachdatasetcontainsimagesfrom2670CCDs.• 30datasetscollectedbetween2016- 2018.• RecordtheaveragetemperatureintheATLAScavernforeachdataset.


20- 15- 10- 5- 0 5 10 15 20Z (m)10-

5-0

510X (m)

10-

5-05

10

Y (

m)

ATLAS Endcap CCD Map

20- 15- 10- 5- 0 5 10 15 20Z (m)10-

5-0

510X (m)

10-

5-05

10

Y (

m)

ATLAS Endcap CCD Map

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NeutronDamageinATLAS

• Wemeasuredalldarkcurrent(usingbrightpixels)presentinourCCDsinATLASonOctober16,2018.• ThedarkcurrentdecreaseswithdistancefromIPalongthebeamlineandradiusfromthebeamlineasexpected.


0

0.002

0.004

0.006

0.008

0.01

0.012

0.014

0.016

0.018

0.02

0 2 4 6 8 10 12 14 16 18 20 22 24Distance in Z (m)

0

2

4

6

8

10

12

(m)

2+y2 x

Radi

al D

istan

ce

counts/px/msOct16: Dark current by distance from IP

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NeutronDamageinATLAS- FLUGG


4-10

3-10

2-10

1-10

1

10

210

310

410

0 2 4 6 8 10 12 14 16 18 20 22 24 |z| (m)

0

2

4

6

8

10

12

r (m

)

)-1Simulated Neutron Dose (after 154 fb = 14TeVsFLUGG, )-2 1MeVNE cm12(10

0

0.05

0.1

0.15

0.2

0.25

0.3

0 2 4 6 8 10 12 14 16 18 20 22 24 |z| (m)

0

2

4

6

8

10

12

r (

m)

a(counts/px/ms/Tn) )-1 Dose (after 154 fb-2 1MeVNE cm12Oct16: Dark Current per 10

C°T = 24 = 14TeVsFLUGG,

= 0.104aavg = 0.247amax

= 0.037amin

http://young.web.cern.ch/young/RadiationMap/

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NeutronDamageinATLAS– GEANT4


4-10

3-10

2-10

1-10

1

10

210

310

410

0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 |z| (cm)

0

200

400

600

800

1000

1200

r (c

m)

)-1Simulated Neutron Dose (after 154 fb = 13TeVsGEANT4, )-2 1MeVNE cm12(10

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0 2 4 6 8 10 12 14 16 18 20 22 24 |z| (m)

0

2

4

6

8

10

12

r (

m)

a(counts/px/ms/Tn) )-1 Dose (after 154 fb-2 1MeVNE cm12Oct16: Dark Current per 10

C°T = 24 = 13TeVsGEANT4,

= 0.172aavg = 0.672amax

= 0.049amin

http://radsim.cern.ch/RadiationSimulation/G4_Run2_NIEL_0_1200_0_2400_1_78.txt

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0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 a

0

5

10

15

20

25

30

35

Num

ber o

f bin

s

value distribution by simluation useda

FLUGG = 0.104aavg

= 0.098amedian

GEANT4 = 0.171aavg

= 0.141amedian

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α Values- FLUGGvs.GEANT4

BRANDEISUNIVERSITY- CamilaPazos21-May-19

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NeutronSpectra


11-10 10-10 9-10 8-10 7-10 6-10 5-10 4-10 3-10 2-10 1-10 1 10 210 310 410 510 610 [MeV]kin E

310

410

510

610

710

810

910

1010

1110

1210

1310

1410-1/0

.2] @

1 fb

2/M

eV

) [1

/cm

kin

(E

10

/ d

log

Fd

kin Neutron Fluences vs. E = 13TeVsGEANT4,

= 0.672, |z| = 2160cm, r = 310cm a max = 0.049, |z| = 760cm, r = 460cm a min

= 0.141, |z| = 1120cm, r = 750cm a med

11-10 10-10 9-10 8-10 7-10 6-10 5-10 4-10 3-10 2-10 1-10 1 10 210 310 410 510 610 [MeV]kin E

310

410

510

610

710

810

910

1010

1110

1210

1310

1410-1/0

.2] @

1 fb

2/M

eV

) [1

/cm

kin

(E

10

/ d

log

Fd

kin Neutron Fluences vs. E = 13TeVsGEANT4,

closest to IP, |z| = 720cm, r = 200cm = 0.109a

farthest from IP, |z| = 2170cm, r = 1190cm = 0.214a

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Conclusion


• Wemeasureddarkcurrentin2670ATLASendcapCCDs.Usingsimulatedneutronfluxdata,wecalculateddarkcurrentperneutrondosereceived.Wecomparedthesemeasurementstotheresultsobtainedinpast,controlledexperiments:

Experiment α (count/px/ms/dose)

1998Lowell 0.28

1999PROSPERO 0.26

2018 ATLAS- FLUGG 0.104

2018ATLAS– GEANT4 0.172

21-May-19

Backup

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

0.2

0.22

0.24

0 2 4 6 8 10 12 14 16 18 20 22 24 |z| (m)

0

2

4

6

8

10

12 r

(m)

a

(counts/px/ms/Tn) )-1 Dose (after 154 fb-2 1MeVNE cm12Oct16: Dark Current per 10

C°T = 24

= 14TeVsFLUGG,

= 0.104aavg = 0.247amax

= 0.037amin

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NeutronDamageinATLAS- FLUGG


0

0.1

0.2

0.3

0.4

0.5

0.6

0 2 4 6 8 10 12 14 16 18 20 22 24 |z| (m)

0

2

4

6

8

10

12 r

(m)

a

(counts/px/ms/Tn) )-1 Dose (after 154 fb-2 1MeVNE cm12Oct16: Dark Current per 10

C°T = 24

= 13TeVsGEANT4,

= 0.172aavg = 0.672amax

= 0.049amin

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NeutronDamageinATLAS– GEANT4


Neutron Damage of Camila Pazos - bndhep.net · BRANDEIS UNIVERSITY -Camila Pazos 0 0.002 0.004...

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