reno liquid scintillator r&d daejung kong (knu) kps spring meeting, april 19, 07 경북대,...
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RENO Liquid Scintillator R&D
Daejung Kong (KNU)
KPS Spring Meeting, April 19, 07
경북대 , 경상대 , 동신대 , 부산대 , 세종대 , 서울대 , 서울시립대 , 성균관대 , 전남대 , INR/IPCE ( 러시아 )
Introduction Gd-LS R&D Purification Summary and plan
Target - LSc + Gd
Gamma catcher - LSc
Buffer - Non Scinti.
Veto - Water
Shielding
pνe
e+e-
γ(0.511MeV)
γ(0.511MeV)
n
Gd
γ
γ γ
γ
Egå ~8MeV
30μs
prompt signal
Delayed signal
Core component
Liquid Scintialltor for RENO
Gadolinium Large neutron X-section, BKG rejection (coincidence)
Liquid Scintillator High light output, good optical properties,
Long term stability, H/C, Radiopurity
2007 KPS spring Meeting 3
Gd+Liquid Scintillator R&D
Liquid Scintillator R&D 에서 수행하는 사항들 :
- 구성물질의 조합과 배합 비율 결정
- 빛 방출량 측정
- 투광도 및 흡광도 측정
- purification system
- 주기적 측정에 의한 장기적 안정성 검사
- 변색 여부 검사
- 아크릴의 거부 반응 여부
Liquid Scintillator 의 일반적 구성 물질 :
Aromatic Oil Fluor WLS Gd-compound
PC(Pseudocumene), PXE, LAB
Mineral oil, Dodecane, Tetradecane, LAB
PPO, BPO
Bis-MSB, POPOP
0.1% Gd compounds with CBX or BDK
2007 KPS spring Meeting 4
Chooz Palo Verde
Gd Gd(NO3)3 Gd2O3
Loading Methods
Dissolved in hexanol + LS Converted to carboxylate + LS
Light degradation
0.4 % / day 0.03 % / day
Remarks Unstable Turned Yellow
Stable still usable
Lesson and R&D about Gd-LS
Gd loading is a key issue
Gd loading is not trivial Experienced Russian Group (INR) joined 6
months stable Gd-LS R&D with INR
2007 KPS spring Meeting 5
Gd compound structure
R1
3+Gd
R2
O
OO
O
O
O
HC-
C-
H
C-H
R1 R1
R2
R2
Gd3+
R
O
OO
O
O
O
C
C
C
R
R
C C
O- H+
O
R
H
H
R C CH2 R 2C
O O
GdCBX GdBDK
-diketonates: Carboxylic acids:
2007 KPS spring Meeting 6
Liquid Scintillator R&D 현황
R&DSafety
와환경문제
Domestic Availability
Remarks
LAB100 RENO/Daya bay Much less toxic
YES Inexpensive, 환경 친화적
PC20Dod80 Daya Bay/RENO toxic NO Expensive
PXE20Dod80 Double Chooz Less toxic NO Unstable claimed by Daya bay
PC20MO80PC40MO60
Palo VerdeChooz toxic Available Components?, purification
2007 KPS spring Meeting 7
Optimization of Fluor and WLS Optical properties (absorption,..) Measurement of Gd concentration purification (transparency, radio-purity) Measurement of LS components Light output - Nitrogen flushing effect
RENO Gd (un)loaded LS R&D 현황
2007 KPS spring Meeting 8
Solvent : LAB 1g PPO2g PPO3g PPO4g PPO5g PPO6g PPO7g PPO10g PPO20g PPO
Optimization of PPO, bis-MSB Concentration
Purified LAB(100) + varying PPO PPO 3g/l 일 때 , LY saturation
0mg/l 10mg/l 20mg/l 30mg/l 40mg/l 50mg/l 60mg/l 100mgl 200mg/l
LAB100+PPO3g/l+bis-MSB30mg/l
2007 KPS spring Meeting 9
Beer-(Lamvert-Bouguer) law
= 0.4343 (L/(A420-Amin))
L: cell path length A: absorption at 420nm
정제 전
정제 후
정제방법 (Al2O3 adsorption)
LAB( 이수화학 ) 흡광도 [Abs] 조사
2007 KPS spring Meeting 10
LAB has lower optical absorption, better attenuation length
100% LAB and PC have similar light outputs
We got similar results with BNL & Daya Bay experiment
100%82%96%
Absorption spectra Light output spectra
Performance of Gd in PC & LAB
Gd loaded Gd unloaded
2007 KPS spring Meeting 11
Sample
Composition(ligand) [Gd](%)
Remarks
첨가물
1 *3HR 0.109 HR(0.92m)
2 *3TBP 0.108 TBP(0.5m)
3 *2TOPO 0.118 TOPO(99%)
4 *3TOPO 0.110 TOPO(99%)
측정 결과
indicatorbuffer solution
EDTA
① PH> 5 에서 Gd 은 EDTA 와 반응도 높다
② EDTA 는 indicator 와 반응해 , 보라색에서 노란색으로 색깔 변화③ VEDTA * CEDTA = Vsample * Csample
Indicator
GdLSBuffer solution(PH>5)
Gdbuffer solution
(PH>5)
Gd 농도 측정 방법
2007 KPS spring Meeting 12
적정횟수 Gd Concentration (%)
1 0.096
2 0.096
3 0.094
측정 Attenuation length (m)
1 5.65
2 6.18
3 6.19
Note LS 관련 약품을 살 때는 모두 고순도를 구입해서 사용해야 ( 특히 , PPO, ligand) If not, additional purification will be needed
Abs
최종 샘플 흡광도 [Abs], att, 농도 조사
2007 KPS spring Meeting 13
정제 전 (m) 정제 후 (m)
PXE 1.0 1.3
Dodecane 15.2 16.2
PC 5.9 8.2
MO 9.7 N/A
LAB (batch1) 9.5 15.2
LAB (batch2) 7.7 14.7
Attenuation Length of different solvents before/after purification
2007 KPS spring Meeting 14
Transmittance of two different batch samples of LAB
B1 B2
정제 전후 차이 없음 정제 후가 better
정제 전B1 > B2투광도 : batch 에 따라 다소 차이
정제 후B1 = B2투광도 batch 에 무관
2007 KPS spring Meeting 15
Optimal ratio of LAB and Alumina for purification
- Optimization• Find optimal ratio of LAB and Al2O3 • Using column adsorption method, take purified LAB for each time, naming as batch1, batch2,… total 10 batches.• Measure the absorption spectrums and calculate the attenuation lengths (at 420 nm) of each batch 1:5 (alumina : LAB)
2007 KPS spring Meeting 16
Radiopurity level 10-13 g/g (Th, U, K) : Daya Bay/Double Chooz
S/N > 100 (DB, DC)
RENO rediopurity level 측정 : ICP-MS( 기초과학지원연구소 )
정제 방법 개선 후 정밀도가 높은 장비로 측정 예정
Radiopurity level in LS Radiopurity level in LS
K [g/g] Th [g/g] U [g/g]Mineral Oil 0.77x10-6 < 2x10-9 < 5x10-10
From Daya Bay TDR
2007 KPS spring Meeting 17
Radiopurity level 10-13 g/g (Th, U, K) : Daya Bay/Double Chooz
S/N > 100 (DB, DC)
RENO rediopurity level 측정 : ICP-MS( 기초과학지원연구소 )
정제 방법 개선 후 정밀도가 높은 장비로 측정 예정
Radiopurity level in LS Radiopurity level in LS
K [g/g] Th [g/g] U [g/g]Mineral Oil 0.77x10-6 < 2x10-9 < 5x10-10
From Daya Bay TDR
2007 KPS spring Meeting 18
Gas Chromatography (GC) with Mass Spectrometry (MS)Gas Chromatography (GC) with Mass Spectrometry (MS)
Measurement of LAB Component using GC-MS
Motivation : calculation of # of proton, H/CLAB : (C6H5)CNH2N+1
Gas Chromatography Mass Spectrometry (MS)Gas Chromatography Mass Spectrometry (MS)
2007 KPS spring Meeting 19
Measurement of LAB Measurement of LAB componentscomponents
LAB : (C6H5)CNH2N+1
2007 KPS spring Meeting 20
C16H26 C17H28 C18H30 C19H32
7.17% 27.63% 34.97% 30.23%
LAB components with GC-LAB components with GC-MSMSLAB : (C6H5)CNH2N+1
# of H [m-3] = 0.631 x 1029
H/C = 1.66
2007 KPS spring Meeting 21
KF-50 KF-70
Measurement of Mineral Oil Measurement of Mineral Oil componentscomponents
Difficult to figure out Component of M.O
* KF-50,KF-70 : 서진화학 M.O
2007 KPS spring Meeting 22
w/o N2 flushing
w/ N2 flushing
Effect of Nitrogen flushing & Effect of Nitrogen flushing & purificationpurification
Light YieldLight Yield
2007 KPS spring Meeting 23
100%82% 96%
N2 flushing is crucial
Effect of Nitrogen flushing & Effect of Nitrogen flushing & purificationpurification
Light YieldLight Yield
2007 KPS spring Meeting 24
Summary and Plan
Current Gd (un)load LS R&D Status
Investigation of Solvents, Fluors
LS mixing procedure developed
Purification method developed
Start Gd loading into LS with Russian Group
Long term R&D Plan
Investigation of radiopurity
Developing mass production techniques (purification, filling, etc.,)
Long term stability R&D (Light Yield, optical properties)
Stability is the most important !!!