1. 2007/Oct/18~19KPS@JEJU1 Liquid Scintillator R&D for RENO Lee, Jaison For RENO Collaboration

2. 2007/Oct/18~19KPS@JEJU2 Contents  Introduction  RENO Detector  Liquid Scintillator Formulation  Gd Loaded LS  Long Term Stability  Radiopurity  LS Purification and Handling System  Summary

3. 2007/Oct/18~19KPS@JEJU3 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  Palo Verde : PC(40%)+M.O.(60%)+PPO+bis-MSB+Gd

4. 2007/Oct/18~19KPS@JEJU4  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

5. 2007/Oct/18~19KPS@JEJU5  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

6. 2007/Oct/18~19KPS@JEJU6  - 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 28032012 Gd(0.1%) +LS 19.715.4 Gamma catcher 4004408LS35.227.5 Buffer tank 5405804 Mineral oil 76.959.2 Veto tank 74078015water201.8

7. 2007/Oct/18~19KPS@JEJU7 화학식 H: C M.W. (g/mol) Density (g/ml) Boiling Point Flash Point Viscosity @20 도 기타 decane C10H22 142.290.73174460.92cps 국내생산 ( 이수화학 ) 장점 dodecane C12H262.17170.340.7493216.271 tetradecane C14H30 198.39220.76725399 PC C9H121.33120.20.89(0.876)16948 인체, 환경유해성 최고. 낮은 FP 문제 LAB C6H5 (CnH2n+ 1) 233-2370.86275-3071305-10cps 나라, 회사마다 quality uncertainty. R&D 결과 없 음. 무해성 PXE C16H181.12210.30.9882951455.2cSt@40 생산지문제 ( 일본생산 ) MO CnH2n+2, n=10-44 ~0.8 ~110 10- 80cSt@40 Np 개수 불확실성 PC20dod80 2 0.78 PXE20dod80 1.96 0.80 >80 PC20MO80 0.857 PC40MO60 0.866 여러 solvent 에 대한 일반적 성 질

8. 2007/Oct/18~19KPS@JEJU8 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)

9. 2007/Oct/18~19KPS@JEJU9 PPO (g/ ㅣ )LY (arb unit)±30 1444.7 2618.7 3649.4 4634.3 5630.9 6579.4 7577.2 10542.7 20505.1  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

10. 2007/Oct/18~19KPS@JEJU10 Bis- MSB(mg/l) PPO(1):bis- MSB ratio LY(arb unit)±30 00668.7 101/300714.7 201/150855.8 301/100917.5 401/75904.4 501/60 601/50873.9 1001/30 2001/15845.1  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

11. 2007/Oct/18~19KPS@JEJU11 Gd Loaded LS + LS 는 solvent 로 유기 용액을 사용. Gd 자체는 유기 용액에 loading 이 안됨. + GdR 3 로 제작해서 사용. R = 2MVA (2 Metyl Valeric Acid) Russia Group 에서 제작하기로 함. + 제작 순서가 중요. 1. GdR 3 + stabilizer : 잘 섞일 때 까지 흔들어줌. 2. Solvent 를 전체 제작 분량에 10% 정도 넣어서 다 녹임 : magnetic stirring 필요 3. 다 녹아서 투명해진 것이 확인 되면 나머지 Solvent 를 넣는다. 주의 : Solvent 를 먼저 넣으면 Gd Loading 이 안 된다. + 적정을 하여 Gd 의 농도를 정확히 측정할 수 있다. ( 0.1% ) Russia 에서 제작한 GdR 3

12. 2007/Oct/18~19KPS@JEJU12 Long Term Stability of GdLS -Samples for long term stability LT 1 : PC100 + 2TOPO + Gd0.1% LT 2 : PC100 + 3HR + Gd0.1% LT 3 : PC100 + 0.1MTBP + Gd0.1% LT 5 : PC20 + dod80 + 2TOPO + Gd0.1% LT 6 : PC20 + dod80 + 3HR + Gd0.1% LT 9 : LAB100 + 2TOPO + Gd0.1% LT10 : LAB100 + 3TOPO + Gd0.1% LT13 : LAB100 + 2TOPO + Gd0.2% LT14 : LAB100 + 3TOPO + Gd0.2% etc… - This test are on going.

13. 2007/Oct/18~19KPS@JEJU13 Radiopurity of LS Gd-LS 의 Radiopurity Level 은 매우 중요함 Systematic Uncertainty 에 직접적인 영향을 줌 Sensitivity 에 영향을 줌 Raidopurity 조건 : ~ 1 Hz 정도의 single rate 초 미량의 Radiopurity 측정은 매우 어려움 측정 radio-active material  232 Th, 238 U, 40 K 측정 방법  ICP-MS, NAA, HP-Ge, etc,. 측정 분해능  일반적인 측정기기는 분해능이 낮음 측정 장소  국내 및 국외 측정 가능한 모든 곳을 고려

14. 2007/Oct/18~19KPS@JEJU14 Radiopurity of LS Sample 238 U 232 Th 40 K Mineral Oil (KBSI) < 5x10 -10 < 2x10 -9 0.8x10 -6 LAB (non-purified) (SNU)ND0.15 LAB (column purified) ND0.33 LAB (vacuum column (VC) purified) ND0.20 LAB (3 times VC purified) ND0.12 LS (LAB+PPO+bis-MSB) column purified ND Detection Limit Th, U < 0.1 ppb (10 -10 g/g) - >10 -12 g/g of radioactivity is required for reducing accidental background. - Now we are measuring radioactivity of LS using ICP-MS at Russia and Japan. - If necessary, LS will be purified further by special methods. (e.g. water extraction)

15. 2007/Oct/18~19KPS@JEJU15 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.

16. 2007/Oct/18~19KPS@JEJU16 진입터널 Wing tunnel LS 공간 Control room LS Handling System in Tunnel

17. 2007/Oct/18~19KPS@JEJU17 Summary  We are doing LS R&D for RENO.  The composition of LS has been optimized.  Gd is successfully loaded to LS, and its concentration can be measured by titration.  We decided the LS formulation for Mockup detector.  We continue to test the long tem stability of LS.  We are designing the LS purification and handling system.  We are going to adapt the results of R&D to Mockup.

18. 2007/Oct/18~19KPS@JEJU18 Back Up

19. 2007/Oct/18~19KPS@JEJU19 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 (%) 107.17 1127.63 1234.97 1330.23

20. 2007/Oct/18~19KPS@JEJU20  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

21. 2007/Oct/18~19KPS@JEJU21 Gd 적정 방법 + 필요한 물품 : 비커, 증류수, GdLS, indicator, buffer solution, EDTA, 적정용 뷰렛 Indicator (Xylenol Orange): 보라색 -> 노란색으로 변함 Buffer solution: 수소이온 농도를 일정하게 유지하려고 하는 용액 EDTA (EthyleneDiamineTetraAcetic acid): Gd 와 높은 반응성 1. 비커에 증류수를 20ml 가량 넣는다. 2. GdLS 를 2ml 넣는다. 3. Buffer solution 2ml + indicator 4 drop : 비커에 담긴 용액이 엷은 보라색을 띈다. 4. 용액의 색이 노란색으로 변할 때까지 EDTA 추가 V EDTA * C EDTA = V GdLS * C GdLS 적정 전의 색끝났을 때의 색 지시약 EDTA Buffer solution 적정용 뷰렛