youngdo oh pohang university of science and technology (ydoh@postech.ac.kr) current status of reno...
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Youngdo OhPohang University of science and Technology
(ydoh@postech.ac.kr)
Current Status of RENONOW2008
(Conca Specchiulla, Italy)
RENO Collaboration
Chonnam National University Chonpook National University Dongshin University Gyeongsang National University Kyungpook National University Pusan National University Sejong University Seoul National University Sungkyunkwan University Pohang University of Science and Technology Institute of Nuclear Research RAS (Russia) Institute of Physical Chemistry and Electrochemistry RAS (Russia) +++ 12institutes, 39 members http://neutrino.snu.ac.kr/RENO
(Reactor Experiment for Neutrino Oscillation)
Located in the west coast of southern part of Korea ~400km from Seoul 6 reactors are lined up in roughly equal distances and span ~1.3 km Total average thermal output ~16.4GWth (2nd largest in the world)
Yong Gwang Nucleat Power Plant
Schematic Setup of RENO at YongGwang
Google Satellite View of YongGwang Site
Schematic View of Underground FacilitySchematic View of Underground Facility
Experimental Hall
Access Tunnel
Detector
(4m high ☓ 4m wide)
TunnelTunnel DetectorDetector
Schedule
Activities
Detector Design& Specification
Geological Survey& Tunnel Design
DetectorConstruction
Excavation &Underground Facility
Construction
DetectorCommissioning
2006 2007 2008 20093 6 9 12 3 6 9 12 3 6 9 12 3 6 9 12
We are here
Comparison of Reactor Neutrino Experiments
Experiments Location
Thermal Power
(GW)
Distances
Near/Far
(m)
Depth
Near/Far
(mwe)
Target Mass
(tons)
Double-CHOOZ France 8.7 280/1050 60/300 10/10
RENO Korea 16.4 290/1380 120/450 15/15
Daya Bay China 11.6 360(500)/1985(1613)
260/910 402/80
Rock sampling (DaeWoo Engineering Co.)Rock samples from boring
For chemical composition, density, radioactivity
• Near detector site: - tunnel length : 110m
- height : 46.1m
• Far detector site: - tunnel length : 272m- height : 168.1m
Rock quality map
Tunnel Design
연속체 안정성 검토
• 터널변위 및 응력해석
불연속체 안정성 검토
• 터널변위 및 응력해석
키블럭 안정성 검토
• 암반 블록파괴 검토
접속부 안정성 검토 확폭 및 수직터널 안정성 검토
• 터널변위 및 응력해석
콘크리트 구조 검토
• 구조물 안정성 검토 • 접속부변위 및 응력해석
Stress analysis for tunnel design
Tunnel Construction is on going ….
Near tunnel
Far tunnel
On-site office
Power Plant
50mFromentrance
Inner Diameter (cm)
vessel Inner Height (cm)
Filled with Mass (tons)
Target Vessel 280 Acryl 320 Gd(0.1%) + LS 15.4
Gamma catcher 400 Acryl 440 LS 27.5
Buffer tank 540 Stainless steel 580 Mineral oil(LAB)
59.2
Veto tank 840 Steel 880 water 354.7
total ~450 tons
Veto
Buffer
Target
-catcher
Four concentric cylindrical parts Identical detectors for near and far Target and gamma catcher are filled with liquid scintillator aiming at detecting inverse beta decay 342 10-inch PMTs on the surface of buffer 67 10-inch PMTs on the VETO
RENO Detector
Target :- Gd + LS
Gamma catcher : - LS
Buffer :- Non scintillating oil
Veto : - Water
Shielding :- Steel
Inverse beta decay in RENO Detector
pνe
e+γ(0.511MeV)
γ(0.511MeV)
n
Gd
γ
γ γ
γ
30μs
prompt signal
Delayed signal
E ~8MeV
CAD views of RENO Detector
Detector Design with MC Simulation
Detector performance study & Detector optimization with MC:
- Gamma catcher size
- Buffer size
- photo-sensor coverage (numbers of PMTs)
- neutron tagging efficiency as a function of Gd concentration
Systematic uncertainty & sensitivity study
Reconstruction(vertex position & energy) program written
Background estimation
RENO-specific MC simulation based on GLG4sim/Geant4 Detailed detector design and drawings are completed
Systematic Errors
Systematic Source CHOOZ (%) RENO (%)
Reactor related absolute
normalization
Reactor antineutrino flux and cross section
1.9 < 0.1
Reactor power 0.7 0.2
Energy released per fission 0.6 < 0.1
Number of protons in target
H/C ratio 0.8 0.2
Target mass 0.3 < 0.1
Detector Efficiency
Positron energy 0.8 0.1
Positron geode distance 0.1 -
Neutron capture (H/Gd ratio) 1.0 < 0.1
Capture energy containment 0.4 0.1
Neutron geode distance 0.1 -
Neutron delay 0.4 0.1
Positron-neutron distance 0.3 -
Neutron multiplicity 0.5 0.05
combined 2.7 < 0.5
Not final, under study
RENO Expected Sensitivity
GLoBES group workshop@Heidelberg – Mention’s talk
SK m2
R&D with the Russian INR/IPCE group (Gd powder supply)
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
R&D on LAB
General Elements of Liquid Scintillator :
Aromatic Oil Flour WLS Gd-compound
PC(Pseudocumene), PXE, LAB
Mineral oil, Dodecane, Tetrdecane, LAB
PPO, BPO Bis-MSB, POPOP
0.1% Gd compounds with CBX or BDK
PC(20%) + Dodecane(80%) + PPO with bis-MSB or BPO
0.1% Gd compounds with CBX or BDK
R&D : Liquid scintillator (1)
Chemicalelements
H:CM.W.
(g/mol)Density(g/ml)
Boiling Point
Flash Point
Viscosity@20℃ comments
decane C10H22 142.29 0.73 174 46 0.92cps Domestically available
dodecane C12H26 2.17 170.34 0.7493 216.2 71 Expensive
tetradecane C14H30 198.3922 0.767 253 99
PC(=TMB) C9H12 1.33 120.2 0.89(0.876) 169 48 Toxic
Low FP
LABC6H5
(CnH2n+1)1.66 233-237 0.86 275-307 130 5-10cps
R&D in progressNontoxicInexpensive
PXE C16H18 1.12 210.3 0.988 295 145 5.2cSt@40 Less toxicSupply limited
MOCnH2n+2, n=10-44
~0.8 ~110 10-80cSt@40
Uncertainty in no. of protons
PC20dod80 2 0.78
PXE20dod80
1.96 0.80 >80
PC20MO80 0.857
PC40MO60 0.866
R&D : Liquid scintillator (2)
R&D with LAB instead of PC/PXE + Dodecane
Light yield measurement
CnH2n+1-C6H5 (n=10~14)
• High Light Yield • 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.
R&D : Liquid scintillator (3)
Measurement of LAB Components with GC-MS
C16H26 C17H28 C18H30 C19H32
7.17% 27.63% 34.97% 30.23%
LAB : (C6H5)CNH2N+1
# of H [m-3] = 0.631 x 1029
H/C = 1.66
R&D : Liquid scintillator (4)
N=10 N=11 N=12 N=13
R&D : Prototype Detector ( 2007 )
The prototype detector was bulit
to test properties liquid scintillator to validate the Monte Carlo Simulation model based on Geant4
Prototype Detector Assembly
Acrylic vessels
Inner acrylic vessel
Nitrogen flushing of LS
Mounting PMTs
Filling with liquid scintillator
assembled prototype
R&D : Mockup Detector ( 1 ) By building mockup detector, we will answer the technical questions for final design of main detector. ~40% scale to the main detector in size and 31 10-inch PMTs
To test
Fabrication in Sepember 2008Data taking from October 2008, for next 6 months
- long tem stability and light transmittance of acrylic tank - source and light calibration- PMT performance in mineral oil- liquid handling system- daq and data manipulation
diameter heightTarget 60cm 60cmGamma catcher 120cm 120cmBuffer 220cm 220cm
R&D : Mockup Detector ( 2 )- PMT installation is done last week.
- DAQ and HV system ready
- Calibration system (this week)
- LS filling from next week
- Data taking from October for 6 months
R&D : Mockup Detector ( 3 )
Source and light calibration system: 137Cs, 60Co, 22Na, 252Cf , LED
DAQ for mockup – 400MHz FADCLiquid handling system
Pulse generator
LED Trigger
Pulse generator
LED Trigger
Pulse generator
LED
Diffuse ball
LED Trigger
R&D : Mockup Detector ( 4 )
Energy response of the mockupto the 137Cs(left) 60Co(right)at the center of the detector
Energy linearity (left) andenergy resolution(right) for positron
Geant4 Monte Calro Simulation
Status Report of RENO RENO is suitable for measuring 13 (sin2(213) > 0.02)
RENO is under construction phase.
Geological survey and design of access tunnels & detector cavities are completed → Excavation started
International collaborators are being invited.
Mockup detector will operate soon.
Data –taking is expected to start in early 2010.
Back up slide
p
νe
e+
e-
γ(0.511MeV)
γ(0.511MeV)
n
Gd
γ
γ γ
γ
E ~ 8MeV
30μs
prompt signal
Delayed signal
Principle of Neutrino Detection
Use inverse beta decay (ve + p e+ + n) reaction process Prompt part: subsequent annihilation of the positron to two 0.511MeV Delayed part: neutron is captured ~200s w/o Gd ~ s w Gd Gd has largest n absorption cross section & emits high energy Signal from neutron capture ~2.2MeV w/o Gd ~ 8MeV w Gd Measure prompt signal & delayed signal “Delayed coincidence” reduces backgrounds drastically
8MeV30μs
1~8MeV
t
Signal Property
Gamma catcher thickness = 20cm
Gamma catcher thickness = 90cm
MeV MeVMeV
Study on -catcher size
Daya Bay45cm: 92%
Chooz70cm: (94.6+/-0.4)%
RENO70cm: (94.28+/-0.54)%60cm: (92.98+/-0.56)%
Gd capture
H capture
Reconstructed vertex: ~8cm at the center of the detector
Reconstruction : vertex & energy
1 MeV (KE) e+
Energy response and resolution:
%)14.00(E
)%03.074.7(EE
visible energy
3.01.29
/MeV 9.08.208
PMT coverage, resolution
~210 photoelectrons per MeV
|y|
y (
mm
)
Evis (MeV)
y
4 MeV (KE) e+
target
buffer
-catcher
Reconstruction of Cosmic Muons
~140cm
~40cm
~120cm
A
B
C
D
Veto(OD)
Buffer(ID)
pulse height timeOD PMTs
ID PMTs
Jμ [cm-2s-1] <Eμ> [GeV]
Far250 m 2.9×10-5 91.7
200 m 8.5×10-5 65.2
Near 70 m 5.5×10-4 34.3
Muon intensity at the sea level using modified Gaisser parametrization + MUSIC or Geant4 (the code for propagating muon through rock)
Calculation of Muon Rate at the RENO Underground
Calculation of Background at the RENO Underground
rate from rock [Hz]
Double CHOOZ
Daya Bay RENO
Rockcomposition
(K) 1.6 ppm (U) 2.00 ppm(Th) 5.0 ppm
(K) 5 ppm(U) 10 ppm(Th) 30 ppm
(K) 4.0 ppm(U) 4.8+/-1.8 ppm(Th) 6.0+/-2.2 ppm * Sample from Chongpyung.
Detector DxH Size [cm]
230x246 (10.3 m3)
320x320 280x320
Shelding 17 cm Steel 2.5 m Water+ 0.45 m Oil
2.5 m Water
Rates (K)[Hz] (U) (Th)
0.86 ~0.89 0.98
0.26 0.65 2.6 (E>1 MeV)
0.210.531.74(E>0.5 MeV)
Total rate ~2.73 Hz 3.5 Hz 2.5 Hz
•03~08, 2006 : Project description to local government, residents, and NGO’s (endorsed by local government)
•03, 2007 : Agreement between KHNP and SNU
•03~10, 2007 : Geological survey and tunnel design are completed.
•12, 2007 : Public hearing for YG residents
•01, 2008 : Safety regulation established and accepted by the atomic energy department of MOST
•05~11, 2008 : Tunnel construction
Efforts for On-site Facility
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