1. Park Kang Soon Seokyeong Univ. Status of the RENO WIN09 @ San Clemente, Pelugia Sep. 14-19, 2009

2. New Reactor Neutrino  13 Experiment  Lower background - Improved detector design - Increased overburden  CHOOZ : R osc = 1.01 ± 2.8% (stat) ± 2.7% (syst)  Larger statistics - More powerful reactors (multi-core) - Larger detection volume - Longer exposure  Smaller experimental errors - Identical multi detectors → Obtain ~1% precision !!!

3. Detection of Reactor Neutrinos data from CHOOZ hep-ex/0301017v1 (1) 0.7<E prompot <9MeV (2) 5<E delayed <11MeV (3) 1μs<ΔT <200μs e + energy n capture energy

4. ExperimentsLocation Thermal Power (GW) Distances Near/Far (m) Depth Near/Far (mwe) Target Mass (tons) Double-CHOOZFrance8.7280/105060/30010/10 RENOKorea16.4290/1380120/45016/16 Daya BayChina11.6360(500)/1985(1613)260/910 40  2/80 Comparison of Reactor Neutrino Experiments

5. RENO Collaboration 11 institutions and 40 persons  Chonnam National University  Dongshin University  Gyeongsang National University  Kyungpook National University  Pusan National University  Sejong University  Seoul National University  Sungkyunkwan University  Seokyeong University  Institute of Nuclear Research RAS (Russia)  Institute of Physical Chemistry and Electrochemistry RAS (Russia) +++ http://neutrino.snu.ac.kr/RENO

6. Summary of Construction Status 03~10, 2007 : Geological survey and tunnel design are completed. 05, 2008 ~ 02, 2009 : Completion of tunnel construction Hamamatsu 10” PMTs have been ordered. (expect to be delivered from Nov. 2009) SK new electronics are ready. 09, 2009 : Steel containers are ready to be assembled. Acrylic containers and mechanical structure are under construction. ( will be done at the end of Nov. 2009 ) Liquid scintillator handling system is being designed in detail. Mock-up detector (~1/10 in volume) is made in Oct. 2008.

7. Schematic View of Underground Facility 100m300m 70m high 200m high 1,380m290m Far Detector Near Detector Reactors

8. Design of Tunnels Experimental hall Detector Wing tunnel(L) Wing tunnel(C) Detector Wing tunnel(C)

9. Construction for the Far Tunnel (July, 2008) (Aug, 2008) (92m) (Sep., 2008) 그림 1) 원거리 입구 모습 Done !

10. Construction for the Near Tunnel (40m) (Oct., 2008) (90m) (Oct., 2008) (Sep., 2008)(July, 2008) Tunnel head (Dec., 2008) Done !

11. Construction for Experimental Hall Done !

12. RENO Detector Inner Diameter (cm) Inner Height (cm) Filled withMass (tons) Target Vessel 280320Gd(0.1%) + LS 16.5 Gamma catcher 400440LS30.0 Buffer tank 540580Mineral oil64.4 Veto tank840880water352.6 total ~460 tons 421 PMTs in total

13. Buffer tank Proceeding of construction by NIVAK Co. Korea Almost done Swing method of construction Cover leak test with water & oil Buffer Veto

14. Acrylic container Proceeding of construction by KOATECH Co. Korea It will be completely done at the end of Nov. Target Gamma catcher A half of targetBanding acrylic plate

15. Electronics  Use SK new electronics (all hardwares are ready) Conceptual design of the system

16. Mockup Detector Target + Gamma Catcher Acrylic Containers (PMMA: Polymethyl Methacrylate or Plexiglass) TargetDiameter61 cm Height60 cm Gamma Catcher Diameter120 cm Height120 cm BufferDiameter220 cm Height220 cm Buffer Stainless Steel Tank

17. Mockup Detector Assembly Being under fine tuning the energy calibration with MC

18. Gd Loaded Liquid Scintillator  Recipe of Liquid Scintillator : Aromatic SolventFlourWLSGd-compound LABPPO (3g/L) Bis-MSB (30mg/L) 0.1% Gd+TMHA (trimethylhexanoic acid)  Optical parameters are checked up.  R&D on LAB(Linear Alkyl Benzene) properties : C n H 2n+1 -C 6 H 5 (n=10~14) High Light Yield : not likely Mineral oil(MO) replace MO and even Pseudocume(PC) Good transparency (better than PC) High Flash point : 147 o C (PC : 48 o C) Environmentally friendly (PC : toxic) Components well known (MO : not well known) Domestically available: Isu Chemical Ltd.

19. Raw/MCDataProductionModulesReconstructionModulesUserAnalysisModulesUserntuples RACFrameWork default modules data input and output, database access for run configuration and calibration Has talk-to function for changing input parameters without recompiling Addition of modules by user Modules can be set as filter module for selecting events Easy to use and build in RENO software environment R Analysis Control RENO Analysis Control

20. J μ [cm -2 s -1 ] [GeV] Far200 m8.5×10 -5 65.2 Near70 m5.5×10 -4 34.3 Calculation of Muon Rate at the RENO Underground Muon intensity at the sea level using modified Gaisser parametrization + MUSIC or Geant4 (the code for propagating muon through rock)

21. Systematic Errors Systematic Source CHOOZ (%) RENO (%) Reactor related absolute normalization Reactor antineutrino flux and cross section 1.9 < 0.1 Reactor power 0.7 < 0.4 Energy released per fission 0.6 < 0.1 Detector related H/C ratio 0.8 0.1 Target mass 0.30.1 Positron energy 0.8 0.05 Positron geode distance 0.10.0 Neutron capture (H/Gd ratio) 1.0 < 0.3 Capture energy containment 0.40.1 Neutron geode distance 0.10.0 Neutron delay 0.40.1 Positron-neutron distance 0.30.0 Neutron multiplicity 0.50.05 combined2.7 < 0.6

22. Calculation of Background Rates due to Radioactivity Concentration 40 K (ppb) Concentration 232 Th (ppb) Concentration 238 U (ppb) 40 K [Hz] 232 Th [Hz] 238 U [Hz] Total [Hz] Rock4.33(ppm)7.58(ppm)2.32(ppm)1.067.140.999.19 LS in Target 0.0010.0010.0010.900.090.261.25 Target Contatiner 0.0080.050.0080.080.060.030.17 LS in Gamma Catcher 0.0010.0010.0011.520.130.382.03 Gamma Catcher Container 0.0080.050.0080.070.040.030.14 LS in Buffer 0.0010.0010.0010.08 ~ 0 ~ 00.030.11 Buffer Tank 0.060.90.90.030.100.200.33 PMT13.6208.549.42.505.232.9910.72 Total~24

23. RENO Expected Sensitivity 10x better sensitivity than current limit New!! (full analysis)

24. GLoBES group workshop@Heidelberg – Mention’s talk SK  m 2

25. Status Report of RENO  RENO is suitable for measuring  13 (sin 2 (2  13 ) > 0.02)  RENO is under construction phase.  Geological survey and design of access tunnels & detector cavities are completed → Tunnel construction has been finished in February, 2009.  International collaborators are being invited.  Data –taking is expected to start in mid 2010.