reno liquid scintillator r&d daejung kong (knu) kps spring meeting, april 19, 07 경북대,...

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


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


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:


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


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


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


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


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


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


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


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


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


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)


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


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)

http://en.wikipedia.org/wiki/Image:Gas_chromatograph.png


Measurement of LAB Measurement of LAB componentscomponents

LAB : (C6H5)CNH2N+1


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


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


w/o N2 flushing

w/ N2 flushing

Effect of Nitrogen flushing & Effect of Nitrogen flushing & purificationpurification

Light YieldLight Yield


100%82% 96%

N2 flushing is crucial

Effect of Nitrogen flushing & Effect of Nitrogen flushing & purificationpurification

Light YieldLight Yield


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 !!!

reno liquid scintillator r&d daejung kong (knu) kps spring meeting, april 19, 07 경북대,...

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