Halide Scintillator Growth & Characterization for Rare Decay Search Presented by Gul Rooh Kyungpook...

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Halide Scintillator Halide Scintillator Growth & Growth & Characterization for Rare Characterization for Rare Decay Search Decay Search Presented by Presented by Gul Rooh Gul Rooh Kyungpook National University Kyungpook National University Republic of Korea Republic of Korea

Transcript of Halide Scintillator Growth & Characterization for Rare Decay Search Presented by Gul Rooh Kyungpook...

Page 1: Halide Scintillator Growth & Characterization for Rare Decay Search Presented by Gul Rooh Kyungpook National University Republic of Korea.

Halide ScintillatorHalide Scintillator Growth & Characterization Growth & Characterization

for Rare Decay Searchfor Rare Decay Search

Presented byPresented by

Gul RoohGul Rooh

Kyungpook National UniversityKyungpook National University

Republic of KoreaRepublic of Korea

Page 2: Halide Scintillator Growth & Characterization for Rare Decay Search Presented by Gul Rooh Kyungpook National University Republic of Korea.

OutlineOutline

• Crystal growing and characterizationCrystal growing and characterization• IntroductionIntroduction• Properties of an ideal scintillation crystalProperties of an ideal scintillation crystal• Crystal growth system by CzochralskiCrystal growth system by Czochralski• γ-ray spectroscopy systemγ-ray spectroscopy system• Grown crystals using Czochralski method at KNUGrown crystals using Czochralski method at KNU• New Czochralski for oxide scintillatorsNew Czochralski for oxide scintillators• Bridgman MethodBridgman Method• CeBrCeBr33 crystal grown by Bridgman method crystal grown by Bridgman method • CeBrCeBr33 crystal for 2 crystal for 2ββ+, +, KKββ+ + andand 2K2K decay searchdecay search

Page 3: Halide Scintillator Growth & Characterization for Rare Decay Search Presented by Gul Rooh Kyungpook National University Republic of Korea.

Crystal growing & characterizationCrystal growing & characterization

Kyungpook National Univ. Kyungpook National Univ.

Pukyong National Univ.Pukyong National Univ.

Dague Health CollegeDague Health College

• Application for radiation detector & medical Application for radiation detector & medical imagingimaging

• Application for the rare decay experimentApplication for the rare decay experiment1.1.Double beta decayDouble beta decay2.2.Dark matter searchDark matter search

Page 4: Halide Scintillator Growth & Characterization for Rare Decay Search Presented by Gul Rooh Kyungpook National University Republic of Korea.

IntroductionIntroductionTo develop new scintillation detectors To develop new scintillation detectors • • Determine optimum crystal growing conditions for Determine optimum crystal growing conditions for the single crystalsthe single crystals • • Confirmation of the crystal structures using XRDConfirmation of the crystal structures using XRD • • Measurement of the emission spectraMeasurement of the emission spectra • • Measurement of the scintillation propertiesMeasurement of the scintillation properties

Pulse height spectra for different radioisotopesPulse height spectra for different radioisotopes Light yieldLight yield Proportionality curve Proportionality curve Energy resolution Energy resolution Fluorescence decay timeFluorescence decay time αα//ββ ratio ratio

Page 5: Halide Scintillator Growth & Characterization for Rare Decay Search Presented by Gul Rooh Kyungpook National University Republic of Korea.

Important properties of an Important properties of an ideal scintillation crystalideal scintillation crystal

• High Density and atomic number (Z)High Density and atomic number (Z)

• High Light output ->good energy resolutionHigh Light output ->good energy resolution

• Decay time Decay time (duration of the scintillation light pulse)(duration of the scintillation light pulse)

• Mechanical and optical propertiesMechanical and optical properties

• Radiation damage hardnessRadiation damage hardness

• CostCost

Page 6: Halide Scintillator Growth & Characterization for Rare Decay Search Presented by Gul Rooh Kyungpook National University Republic of Korea.

Crystal growth system by Crystal growth system by CzochralskiCzochralski

Pt BAR & Pt WIRE

SEED

ALUMINA TUBE

WINDOW

CRYSTAL

R.F. COIL

THERMO COUPLE

Pt CRUCIBLE

FIRE-BRICK

Outside Inside

Page 7: Halide Scintillator Growth & Characterization for Rare Decay Search Presented by Gul Rooh Kyungpook National University Republic of Korea.

Czochralski crystal growth Czochralski crystal growth processprocess

WeighingWeighing

CuttingCutting

GrowingGrowing3 mm/hr 25 rpm in Ar3 mm/hr 25 rpm in Ar

PolishingPolishing10 10 10 mmⅹ ⅹ10 10 10 mmⅹ ⅹ 33

Page 8: Halide Scintillator Growth & Characterization for Rare Decay Search Presented by Gul Rooh Kyungpook National University Republic of Korea.

Grown crystals using Grown crystals using Czochralski & Bridgman Czochralski & Bridgman

method at KNUmethod at KNU

PbClPbCl22:Eu:Eu

CsICsI PbClPbCl22

CsSrClCsSrCl33

CsClCsCl33:Ce:Ce

LaClLaCl33:Ce:Ce

SrClSrCl22:Eu:Eu

BaBaxxSrSr1-x1-xClCl22

Page 9: Halide Scintillator Growth & Characterization for Rare Decay Search Presented by Gul Rooh Kyungpook National University Republic of Korea.

γ-ray spectroscopy γ-ray spectroscopy systemsystem

Crystal PMT

400 MHzFADC

High VoltageComputer

RootRoot Dark BoxDark Box

FADCFADC

Pre-AmpPre-Amp

OscilloscopeOscilloscope

Page 10: Halide Scintillator Growth & Characterization for Rare Decay Search Presented by Gul Rooh Kyungpook National University Republic of Korea.

CsClCsCl33:Ce:Ce with with 137137Cs Cs γγ-- rays rays

By Jinho MoonBy Jinho Moon

Page 11: Halide Scintillator Growth & Characterization for Rare Decay Search Presented by Gul Rooh Kyungpook National University Republic of Korea.

LaClLaCl33:Ce:Ce3+ 3+ with with 137137CsCs γγ-- rays rays

By Jinho MoonBy Jinho Moon

Page 12: Halide Scintillator Growth & Characterization for Rare Decay Search Presented by Gul Rooh Kyungpook National University Republic of Korea.

Energy resolution & light yield of Energy resolution & light yield of the SrClthe SrCl22:Eu:Eu2+2+ depending on Eu depending on Eu2+2+

concentrationsconcentrations

By Jinho Moon By Jinho Moon

0.1 0.2 0.3 0.4 0.5 0.6 0.7

6

8

10

12

14

En

erg

y R

eso

luti

on

( %

)

Concentrations of Eu2+ ( mol% )

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.70.0

0.5

1.0

1.5

2.0

Lig

ht

Yie

ld /

Lig

ht

Yie

ld o

f C

sI(T

l)

Concentrations of Eu2+ (mol%)

Page 13: Halide Scintillator Growth & Characterization for Rare Decay Search Presented by Gul Rooh Kyungpook National University Republic of Korea.

New Czochralski for Oxide New Czochralski for Oxide scintillatorsscintillators

• Today we have new czochralski for bigger crystals and Today we have new czochralski for bigger crystals and high melting point powders i.e. Oxides.high melting point powders i.e. Oxides.

• It is under observation for the temperature controlling.It is under observation for the temperature controlling.

10 times bigger

Page 14: Halide Scintillator Growth & Characterization for Rare Decay Search Presented by Gul Rooh Kyungpook National University Republic of Korea.

Bridgman Method

Page 15: Halide Scintillator Growth & Characterization for Rare Decay Search Presented by Gul Rooh Kyungpook National University Republic of Korea.

CeBrCeBr33 by Bridgman Method by Bridgman Method

• Short decay time <20nsShort decay time <20ns• Good energy resolution (5% FWHM)Good energy resolution (5% FWHM)

By Sejin RaBy Sejin Ra

Page 16: Halide Scintillator Growth & Characterization for Rare Decay Search Presented by Gul Rooh Kyungpook National University Republic of Korea.

Relative light yield of CeBrRelative light yield of CeBr33 single crystal with Bialkali PMTsingle crystal with Bialkali PMT

Page 17: Halide Scintillator Growth & Characterization for Rare Decay Search Presented by Gul Rooh Kyungpook National University Republic of Korea.

CeBrCeBr33 for 2 for 2ββ++,, KKββ+ + and 2K decayand 2K decay searchsearch

• 136136Ce has Q-value = 2400keV Ce has Q-value = 2400keV • Natural abundance =0.185%Natural abundance =0.185%• Exp: calculated half life for 0Exp: calculated half life for 0vv

6.9x106.9x1017 17 yrs (2yrs (2ββ++) ) (By Bernabei e(By Bernabei et.alt.al)) 3.8x103.8x1016 16 yrs (Kyrs (Kββ+ + ) ) (By Danevich e(By Danevich et.alt.al)) 6.0x106.0x1015 15 yrsyrs (2K) (2K) (By Danevich (By Danevich et.alet.al))

• Under investigation for rareUnder investigation for rare decaydecay search at Y2L lab.search at Y2L lab.

• SrClSrCl22(Pure) single crystal for EC/(Pure) single crystal for EC/ββ+ + (Presented by J.H.So)(Presented by J.H.So)

Page 18: Halide Scintillator Growth & Characterization for Rare Decay Search Presented by Gul Rooh Kyungpook National University Republic of Korea.

SummarySummary

• To develop new halide scintillators for nuclear & To develop new halide scintillators for nuclear & high energy physics experiments & medical high energy physics experiments & medical imaging.imaging.

• Crystal growth system by CzochralskiCrystal growth system by Czochralski• γ-ray spectroscopy systemγ-ray spectroscopy system• Some developed crystals by CZ technique at KNUSome developed crystals by CZ technique at KNU• New CZ for Oxides and bigger crystals growthNew CZ for Oxides and bigger crystals growth• Bridgman MethodBridgman Method

• CeBrCeBr33 crystal scintillation properties and for the crystal scintillation properties and for the

study of rarestudy of rare decay searchdecay search

Page 19: Halide Scintillator Growth & Characterization for Rare Decay Search Presented by Gul Rooh Kyungpook National University Republic of Korea.

• Number of nuclei of Ce in GSO:Ce =4.1 × 1019

• Emission wavelength of CsI:Tl =540nm

Page 20: Halide Scintillator Growth & Characterization for Rare Decay Search Presented by Gul Rooh Kyungpook National University Republic of Korea.

CeBr3

200 250 300 350 400 450 500 550

0.0

0.2

0.4

0.6

0.8

1.0

Excitation

em : 235 nm

Emission ex

: 368 nm

Inte

nsit

y (

Arb

.Un

it)

Wavelength (nm)