Liquid Scintillator R&D for RENO Lee, Jaison For RENO Collaboration

Contents  Introduction  RENO Detector  Liquid Scintillator Formulation  Gd Loaded LS  Long Term Stability  Radiopurity  LS Purification and Handling System  Summary

AromaticOilFluorWLSGd-compound PC(Pseudocumene) PXE LAB Mineral oil Dodecane Tetradecane LAB PPO BPO Bis- MSB POPOP 0.1% Gd compounds with CBX or BDK Introduction General Compositions of Liquid Scintillator (LS) Other Experiments  KamLAND : PC(20%)+Dodecane(80%)+PPO  Chooz :  Palo Verde : PC(40%)+M.O.(60%)+PPO+bis-MSB+Gd

 Anti-neutrino Target (Gd loaded) - Light Yield ↑ : Good Scintillating Material - Attenuation Length↑ : Transparency ↑ - Stability↑ : Compatible with Acryl Vessel - # of free Proton ↑ : H/C ↑ - Systematic error ↓ : Well understanding mono-molecule, Radiopurities ↓  Gamma Catcher - Light Yield ↑ : Good Scintillating Material - Attenuation Length ↑ : Transparency↑ - Stability↑ : Compatible Acryl Vessel - Systematic error ↓ : Radiopurities ↓ Introduction

 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  INR/IPCE 러시아 그룹 (Gd powder 생산 ) 과 공동연구 : 2 회 방문연구 수행 Introduction

 - catcher buffer PMT surface 1.4m1.6m 0.6m veto 0.7m 1m 0.177m Target RENO Detector Target : LS + Gd (0.1%) Gamma Catcher : LS Buffer : M.O. Veto : Water Inner Diamet er (cm) Inner Height (cm) Thicknes s (mm) Filled with Volume (m 3 ) Mass (tons) Target vessel Gd(0.1%) +LS Gamma catcher LS Buffer tank Mineral oil Veto tank water201.8

화학식 H: C M.W. (g/mol) Density (g/ml) Boiling Point Flash Point 도 기타 decane C10H cps 국내생산 ( 이수화학 ) 장점 dodecane C12H tetradecane C14H PC C9H (0.876)16948 인체, 환경유해성 최고. 낮은 FP 문제 LAB C6H5 (CnH2n+ 1) cps 나라, 회사마다 quality uncertainty. R&D 결과 없 음. 무해성 PXE 생산지문제 ( 일본생산 ) MO CnH2n+2, n=10-44 ~0.8 ~ Np 개수 불확실성 PC20dod PXE20dod >80 PC20MO PC40MO 여러 solvent 에 대한 일반적 성 질

PC 와 Mineral oil/Dodecane 대용으로 사용할 수 있는 LAB(Linear Alkylbenzene) 의 분자 구조식 PC/PXE + Dodecane 의 대용으로 LAB 사용 가능성 연구 High Light Yield : not likely Mineral oil(MO) replace MO and even Pseudocume(PC) probably Good transparency: better than PC High Flash point : 147 o C (PC : 48 o C) Environmentally friendly (PC : toxic) Components well known, Mineral Oil : not well known Domestically available: Isu Chemical Ltd. Light yield measurement PC100% LAB100% PC40% PC20% LAB100% PC20% N2 LAB60% LAB80% MO80% C n H 2n+1 -C 6 H 5 (n=10~14)

LS Formulation

PPO (g/ ㅣ )LY (arb unit)±  Purified LAB(100) + varying PPO  PPO 3g/l 일 때, LY saturation LAB100 + PPO3g/l  PC 보다 PPO 가 잘 녹지는 않는다 RENO 측정 (LAB100) 1g PPO 2g PPO 3g PPO 4g PPO 5g PPO 6g PPO 7g PPO 10g PPO 20g PPO PPO Concentration

Bis- MSB(mg/l) PPO(1):bis- MSB ratio LY(arb unit)± / / / / /60 601/ / /  bis-MSB 양 증가에 따른 LY 최적값을 찾을 수 있다  LAB100+PPO3g/l+bis-MSB30mg/l  60mg 이 넘어가면, solubility 가 나빠짐 Baseline: LAB100PPO3g/l + varying bis-MSB 0mg/l 10mg/l 20mg/l 30mg/l 40mg/l 50mg/l 60mg/l 100mgl 200mg/l 1/100 1/15 bis-MSB Concentration

Gd Loaded LS

Gd Loaded LS

Long Term Stability of LS

Radiopurity of LS

Schematic Design for LS Purification and Handling System N2N2 Detector P LS P GdLS P MO P pump micro filter flow meter mass flow meter valve 200L 1~2 L/min W.E.

Summary

Back Up

공대정 C n H 2n+1 -C 6 H 5 (n=10~14) n=10 n=11 n=12 n=13 LAB Component with GC-MS n 성분비 (%)

 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 w/o Gd