Performance Evaluation of SiPM Performance Evaluation of SiPM Arrays under Strong Magnetic Arrays under Strong Magnetic

FieldsFieldsS España1, G Tapias2, L M Fraile1, J L Herraiz1, E Vicente1,3,

J M Udias1, M Desco2, J J Vaquero2

1Grupo de Física Nuclear, Dpto. Física Atómica, Molecular y Nuclear, Universidad Complutense, Madrid, Spain 2Unidad de Medicina y Cirugía Experimental, Hospital General Universitario Gregorio Marañón, Madrid, Spain 3Instituto de Estructura de la Materia, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain

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IntroductionIntroduction

SiPM (G-APD, MPPC, …) have many advantages compared to APD and PMT:

•High gain•Low Voltage•Fast Timing•Compact size•Low cost•Compatible with magnetic fields

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Calorimeter Tests of SiPMsCalorimeter Tests of SiPMs

CALICE-HCAL (ILC): CAlorimeter for the Linear Collider Experiment

CALICE-HCAL (ILC): CAlorimeter for the Linear Collider Experiment

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GoalsGoals

• Previous results: Previous results:

SiPMs (1 × 1 mmSiPMs (1 × 1 mm22))

• New results:New results:

2 x 2 SiPM array (6 × 6 mm2 x 2 SiPM array (6 × 6 mm22))

Strong Magnetic Field (7 Tesla)Strong Magnetic Field (7 Tesla)

1 mm1 mm

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MaterialsMaterials

VendorVendorActive Active

area (mmarea (mm22))Number of Number of

PixelsPixelsPixel Pixel

size (size (μμm)m)PDE PDE (%)(%)

Hamamatsu

(2 × 2 array)6 × 6

3600/

element50 5050

Single crystalSingle crystalCrystal matrixCrystal matrix

4 × 44 × 4

10 10 × 10 × 20 mmmm33 LYSO LYSO 1.5 x 1.5 x 12 mm1.5 x 1.5 x 12 mm33 LYSO LYSO

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Bruker BioSpec 70/20 USR7 Tesla

LIM – Hospital Gregorio Marañón

MaterialsMaterials

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Experimental SetupExperimental Setup1.- Single crystal1.- Single crystal

LYSO crystal (10 × 10 × 20 mm3) LYSO crystal (10 × 10 × 20 mm3)

22Na22NaSiPM covers 36% SiPM covers 36%

of scintillator baseof scintillator baseSiPM covers 36% SiPM covers 36%

of scintillator baseof scintillator base

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Pulse ShapePulse Shape

NO preamplifierNO preamplifierNO preamplifierNO preamplifier

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Gain vs VoltageGain vs Voltage

T=20ºC

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Gain vs TemperatureGain vs Temperature

Bias = 69.0 V

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Dynamic RangeDynamic Range

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Energy spectra Energy spectra 2222NaNa

ΔE@511 keV = 14%ΔE@511 keV = 14%

Bias = 69.0 VT = 20ºC

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Experimental SetupExperimental Setup2.- Crystal matrix2.- Crystal matrix

4 × 4 LYSO matrix (1.5 × 1.5 × 12 mm3) 4 × 4 LYSO matrix (1.5 × 1.5 × 12 mm3)

18F18F

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Flood Field ImageFlood Field Image

•18F• 68.2 V - 20ºC• 5·105 counts• SoftwareAnger logic

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Flood Field ImageFlood Field Image

•18F• 68.2 V - 20ºC• 5·105 counts• SoftwareAnger logic Peak to valley ratio = 10:1

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Crystal Energy SpectrumCrystal Energy Spectrum

•18F• 68.2 V - 20ºC• 3·104 counts/crystal

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Energy Resolution @ 511keVEnergy Resolution @ 511keV

FWHM (%) 0 Tesla 7 Tesla

Center 11.2 11.9

Center Edge row 14.1 14.4

Corner 21.7 21.4

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ConclusionsConclusions

• The 2 × 2 SiPM array from Hamamatsu shows very good suitability for its use in the presence of strong magnetic fields.

• Monitoring of Temperature and Voltage is needed to correct gain variations.

• Combination with LYSO crystals shows potential to obtain energy resolution below 10% @ 511 keV.

• The 4 × 4 crystal array of 1.5 mm pitch size was perfectly resolved with negligible differences at 0 and 7 Tesla.

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Future SiPMsFuture SiPMs

1 × 4 channels array1 × 4 channels array1 × 4 mm1 × 4 mm22

1 × 1 mm1 × 1 mm22 / channel / channel 25/50/100 μm

4 × 4 channels array4 × 4 channels array16 × 16 mm16 × 16 mm22

3 × 3 mm3 × 3 mm22 / channel / channel25/50/100 μm