N eutrino E xtended S ubmarine T elescope with O ceanographic R esearch
R eactor E xperiment for N eutrino O scillation Liquid Scintillator R&D
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Reactor Experiment for Neutrino Oscillation Liquid Scintillator R&D JS Park for RENO Collaboration □ Transparency □ High light yield □ Long term stability □ High radiopurity □ Safety matter □ Reasonable price □ Massive quantity available Liquid Scintillator ingredients : Base solvent + primary scintillating fluor + secondary wavelength shifter Effect of wavelength shifter Before After PMT sensitive region •Internal background material : 238 U, 232 Th, 40 K • PMT glass is dominant internal background material : ~10Hz • LS radioimpurity contribute to background : ~2Hz (10 -12 g/g) Sample Th U ICP- MS(g/g) 1.1E-12 8E-13 MC simulation of internal background E 4 L m sin ) 2 ( sin cos E 4 L m sin ) 2 ( sin 1 ) ( P 2 21 2 12 2 13 4 2 31 2 13 2 e e Introduction eta 13 measuring Experiment o Identical Detectors : Lower Experimental errors : ~1% level !! wer Reactors : 6-core rge Volume Detector : 15 tons wer Background : Increase overburden Reaction in the Detector Detector Configuration Inverse Beta Decay Delayed signal prompt signal e n p e Neutron captured by Gadolinium P n Gd Total E~8MeV Target : Gd-LS Catcher : LS Buffer : Mineral-Oil Veto : Water 4-cylindrical detector Base solvent For mixing Fluor Wave-length shifter PC , LAB MO, Dodecane PPO, BPO bis-MSB, POPOP General Elements of Liquid Scintillator Gd-CBX Liquid Scintillator Gd-CBX synthesis process Gd-CBX precipitated !! Reaction equation 1. RCOOH + NH 3 •H 2 O ->RCOONH 4 + H 2 O 2. 3RCOONH 4 (aq) + GdCl 3 *6H 2 O -> Gd(RCOO) 3 + 3NH 4 Cl Gd-CBX powder was rinsed with 18MΩ water for several times and dried in vacuum desiccator. We can check whether we truly make Gd-CBX power with FT-IR Spectroscopy. 1. No OH group (3200~3500) 2. No free acid peak (~1700) 3. We have Carboxylic peak (~1420, ~1580) Quality check pH 7.4 pH 6.5 pH 6.2 pH 6.0 pH 5 pH 9.7 pH 7.5 pH 7.2 OH group Free acid peak After reaction pH Neutralization pH □ Gd have large neutron capture cross section : ~49000 barn □ Gd needs to transform to Gd-CBX for loading into organic phase Gd to Gd-CBX Gd-CBX powder for RENO Detector FT-IR Graph Carboxylic peak No OH Group No Free Acid □ Final Gd-CBX powder □ After grinding, store in a petri dish Loading into LAB and purity □ We can load Gd-CBX into LAB by 0.1% (1g/L). □ ~ 95% of purity has been achieved. Required Properties LY saturated when PPO 3g/L and bis-MSB 30mg/L Bis-MSB PPO Fluor Optimization 20mL Liquid Scintillator Reference - CsI Crystal with3cm*3cm*3cm Compton edge Photo peak Light Yield Measurement Radioactive Background ICP-MS result of radioimpurity Using Cs source : 0.662MeV ~30us θ 13 Dominant θ 12 Dominant Near Detector Far Detector Survival probability with respect to baseline(L) Compton edge
description
R eactor E xperiment for N eutrino O scillation Liquid Scintillator R&D JS Park for RENO Collaboration. Gd have large neutron capture cross section : ~49000 barn Gd needs to transform to Gd -CBX for loading into organic phase. pH 7.4. pH 5. Compton edge. Photo peak. - PowerPoint PPT Presentation
Transcript of R eactor E xperiment for N eutrino O scillation Liquid Scintillator R&D
Reactor Experiment for Neutrino Os-cillation
Liquid Scintillator R&DJS Park for RENO Collaboration
□ Transparency□ High light yield□ Long term stability□ High radiopurity □ Safety matter□ Reasonable price□ Massive quantity available
Liquid Scintillator ingredients: Base solvent + primary scintillating fluor + secondary wavelength shifter
Effect of wavelength shifter
Before
After
PMT sensitive region
•Internal background material : 238U, 232Th, 40K
• PMT glass is dominant internal background material : ~10Hz
• LS radioimpurity contribute to background : ~2Hz (10-12 g/g)
Sample Th U
ICP-MS(g/g)
1.1E-12 8E-13
MC simulation of internal background
E4Lm
sin)2(sincosE4
Lmsin)2(sin1)(P
2212
122
134
2312
132
ee
IntroductionTheta 13 measuring Experiment□ Two Identical Detectors : Lower Experimental errors : ~1% level !!□ Power Reactors : 6-core□ Large Volume Detector : 15 tons□ Lower Background : Increase overburden
Reaction in the Detector Detector Configuration
Inverse Beta Decay
Delayed signal
prompt signal
enpe
Neutron captured by Gadolinium
P n
Gd Total E~8MeV
Target : Gd-LSCatcher : LSBuffer : Mineral-OilVeto : Water
4-cylindrical detector
Base solvent For mixing FluorWave-length
shifter
PC , LAB MO, Dodecane PPO, BPO bis-MSB, POPOP
General Elements of Liquid Scintillator
Gd-CBX
Liquid Scintillator
Gd-CBX synthesis process
Gd-CBX precipitated !!
Reaction equation
1. RCOOH + NH3•H2O ->RCOONH4 + H2O
2. 3RCOONH4(aq) + GdCl3*6H2O -> Gd(RCOO)3 + 3NH4Cl
Gd-CBX powder was rinsed with 18MΩ water for several times and dried in vacuum desiccator.
We can check whether we truly make Gd-CBX power with FT-IR Spectroscopy.1. No OH group (3200~3500)2. No free acid peak (~1700)3. We have Carboxylic peak (~1420, ~1580)
Quality check
pH 7.4
pH 6.5
pH 6.2
pH 6.0
pH 5
pH 9.7
pH 7.5
pH 7.2
OH group
Free acid peak
After reaction pH Neutralization pH
□ Gd have large neutron capture cross section : ~49000 barn□ Gd needs to transform to Gd-CBX for loading into organic phase
Gd to Gd-CBX
Gd-CBX powder for RENO Detector
FT-IR Graph
Carboxylic peak
No OH Group
No Free Acid
□ Final Gd-CBX powder□ After grinding, store in a petri dish
Loading into LAB and purity□ We can load Gd-CBX into LAB by 0.1% (1g/L).□ ~ 95% of purity has been achieved.
Required PropertiesLY saturated when PPO 3g/L and bis-MSB 30mg/L
Bis-MSB
PPO
Fluor Optimization
20mL Liquid Scintillator
Reference - CsI Crystal with3cm*3cm*3cm
Compton edge
Photo peak
Light Yield Measurement Radioactive Background
ICP-MS result of radioimpurity
Using Cs source : 0.662MeV
~30us
θ13 Dominant
θ12 Dominant
Near DetectorFar Detector
Survival probability with respect to baseline(L)
Compton edge
