Results in Neutrino Oscillations from SuperKamiokande I

1
Current Status of RENO
(Symposium on Physics of Massive Neutrinos
May 20-22, 2008, Milos, Greece)
Soo-Bong Kim Seoul National Univ.
2
New Reactor Neutrino q13 Experiment

• CHOOZ Rosc 1.01 2.8 (stat) 2.7 (syst)

• Larger statistics
• - More powerful reactors (multi-core)
• - Larger detection volume
• - Longer exposure

? Obtain 1 precision !!!

• Smaller experimental errors
• - Identical multi detectors

• Lower background
• - Improved detector design
• - Increased overburden

3
Detection of Reactor Neutrinos
data from CHOOZ hep-ex/0301017v1
4
RENO Collaboration

• Chonnam National University
• Dongshin University
• Gyeongsang National University
• Kyungpook National University
• Pusan National University
• Sejong University
• Seoul National University
• Sungkyunkwan University
• Institute of Nuclear Research RAS (Russia)
• Institute of Physical Chemistry and
  Electrochemistry RAS
  
• (Russia)
• http//neutrino.snu.ac.kr/RENO

5
(No Transcript)
6
Schematic Setup of RENO at YeongGwang
7
Google Satellite View of YeongGwang Site
8
Schematic View of Underground Facility
9
Schedule
10
Comparison of Reactor Neutrino Experiments
11
Summary of Construction Status

• 0310, 2007 Geological survey and tunnel design
  are completed.
  
• 0512, 2008 Tunnel construction
• Hamamatsu 10 PMTs are considered to be
  purchased.
  
• (expect to be delivered from March 2009)
• SK new electronics are adopted and ordered.
• (will be ready in Sep. 2008)
• Steel/acrylic containers and mechanical structure
  will be ordered soon.
  
• Liquid scintillator handling system is being
  designed.
  
• Mock-up detector (1/4 in length) will be made in
  June, 2008.
  

12
Rock sampling (DaeWoo Engineering Co.)
Rock samples from boring
13
Rock quality map

• Near detector site
• tunnel length 110m
• overburden
• height 46.1m

14
Stress analysis for tunnel design
15
(No Transcript)
16
Detector Design with MC Simulation

• RENO-specific MC simulation based on
  GLG4sim/Geant4
  
• Detailed detector design and drawings are
  completed

• Detector performance study Detector
  optimization with MC
  
• - Gamma catcher size
• - Buffer size
• - photo-sensor coverage (no. of PMTs)
• - neutron tagging efficiency as a function
  of Gd concentration

• Reconstruction(vertex position energy) program
  written

• Systematic uncertainty sensitivity study

• Background estimation

17
RENO Detector
total 460 tons
18
RENO Detector
19
Electronics

• Use SK new electronics

(will be ready in Sep., 2008)
20
Source Driving System
21
Prototype Detector Assembly
Acrylic vessels
Inner acrylic vessel
Mounting PMTs
Nitrogen flushing of LS
assembled prototype
Filling with liquid scintillator
22
Mockup Detector
Target Gamma Catcher Acrylic Containers
(PMMA Polymethyl Methacrylate or Plexiglass)
Buffer Stainless Steel Tank
23
MC of Mockup Detector
60Co
137Cs
24
Gd Loaded Liquid Scintillator

• Recipe of Liquid Scintillator

• Recipe with various mixture performance (light
  yield, transmission attenuation lengths),
  availability, cost, etc.
  
• Design of purification system flow meter
• Long-term stability test
• Reaction with acrylic?
• RD on LAB

25
Synthesis of Gd-carboxylate
Rinse with 18MO water
Dryer
26
RD with LAB
CnH2n1-C6H5 (n1014)
Light yield measurement

• High Light Yield not likely Mineral oil(MO)
• replace MO and even Pseudocume(PC) probably
• Good transparency (better than PC)
• High Flash point 147oC (PC 48oC)
• Environmentally friendly (PC toxic)
• Components well known (MO not well known)
• Domestically available Isu Chemical Ltd. (????)

PC100 LAB100 PC40 PC20 LAB100 PC20
N2 LAB60 LAB80
MO80
27
Measurement of LAB Components with GC-MS
28
Reconstruction vertex energy

• Reconstructed vertex ? 8cm at the center of
  the detector

• Energy response and resolution

29
Reconstruction of Cosmic Muons
30
Calculation of Background Rates due to
Radioactivity
31
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)
32
Systematic Errors
33
RENO Expected Sensitivity
10x better sensitivity than current limit
34
GLoBES group workshop_at_Heidelberg Mentions talk
35
Status Report of RENO

• RENO is suitable for measuring q13 (sin2(2q13)
  0.02)

• Geological survey and design of access tunnels
  detector cavities are completed ? Civil
  construction will begin in early June, 2008.

• RENO is under construction phase.

• Data taking is expected to start in early 2010.

• TDR will be ready in June of 2008.

• International collaborators are being invited.