Soo-Bong Kim Seoul National Univ. RENO for Neutrino Mixing Angle 13 (“Neutrinos in Cosmology, in...
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Transcript of Soo-Bong Kim Seoul National Univ. RENO for Neutrino Mixing Angle 13 (“Neutrinos in Cosmology, in...
Soo-Bong KimSeoul National Univ.
RENO for Neutrino Mixing Angle 13
(“Neutrinos in Cosmology, in Astro-, Particle- and Nuclear Physics”
Sep. 16-24, 2009, Erice/Sicily, Italy)
New Reactor Neutrino 13 Experiment
Lower background - Improved detector design - Increased overburden
CHOOZ : Rosc = 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 !!!
arXiv:0905.3549v2, Fogli et. al.
Hint of 13 >0 from different data sets and combinations : 1 range
Detection of Reactor Neutrinos
8MeV30μs
1~8MeV
t
Signal Propertyp
νe
e+
e-
γ(0.511MeV)
γ(0.511MeV)
n
Gd
γ
γ γ
γ
E ~ 8MeV
30μs
prompt signal
Delayed signal
data from CHOOZ hep-ex/0301017v1
(1) 0.7<Eprompot <9MeV (2) 5<Edelayed <11MeV
(3) 1μs<ΔT <200μs
e+ energy n capture energy
RENO Collaboration (11 institutions and 40 physicists) 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
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 17.3 290/1380 120/450 16/16
Daya Bay China 11.6 360(500)/1985(1613) 260/910 402/80
Schematic Setup of RENO at YongGwang
Google Satellite View of YongGwang Site
Schematic View of Underground FacilitySchematic View of Underground Facility
100m 300m
70m high
200m high
1,380m
290m Far Detector
Near Detector Reactor
s
RENO Detector
Inner Diameter (cm)
Inner Heigh
t (cm)
Filled with
Mass (tons
)
Target Vesse
l
280 320 Gd(0.1%) + LS
16.1
Gamma catch
er
400 440 LS 28.5
Buffer tank
540 580 Mineral oil
64.4
Veto tank
840 880 water 352.6total ~460 tons
421(354+61) 10” PMTs
Schedule
Summary of Construction Status•03~10, 2007 : Geological survey and tunnel design are completed.
•07~11, 2008 : Construction of both near and far tunnels are completed.
•12, 2008 ~ 03, 2009 : Veto tanks and peripheral facilities (electricity, air circulation, drainage, network, etc.) are completed.
•10, 2008 : A mockup detector (~1/10 in volume) was built and is tested out.
•11, 2008 : SK new electronics were adopted and ready.
•Steel/acrylic containers and mechanical structures are under installation and will be completed until Nov. 2009.
•PMT installation is expected to start from Dec. 2009.
•Both near and far detectors are expected to be ready for data-taking in mid 2010.
Rock quality map
• Near detector site: - tunnel length : 110m
- overburden
height : 46.1m
• Far detector site: - tunnel length : 272m- overburden
height : 168.1m
(2007.3~2007.8)
Design of Tunnels
Experimental hall
Experimental hall
Win
g
tun
nel(L
)
Wing tunnel(C)
Detector
Win
g
tun
nel(C
)
Access tunnel
Access tunnel
Detectorvertical
hall
(2007.9~2007.11)
Near & far tunnels are completedby Daewoo Eng. Co. Korea(2008.6~2009.
3)
Detector vertical halls are ready(2008.12~2009.2
)
Buffer steel tanks are installedby NIVAK Co. Korea(2009.6~2009.9)
Acrylic vessels will be ready in Nov. 2009
by KOATECH Co. Korea
Target
Gam
ma c
atc
her
A half of target
Bending acrylic plates
(2009.7~2009.11)
Mockup Detector
Target + Gamma Catcher Acrylic Containers(PMMA: Polymethyl Methacrylate or Plexiglass)
Target Diameter
61 cm
Height 60 cm
Gamma
Catcher
Diameter
120 cm
Height 120 cm
Buffer Diameter
220 cm
Height 220 cm
Buffer Stainless Steel Tank
~1/10 of RENO in volume
Mockup Detector Assembly
Energy Calibration of Mockup Detector
137Cs
60Co
252Cf
137Cs
60Co
Electronics Use SK new electronics(all hardwares are ready)
Conceptual design of the system
Gd Loaded Liquid Scintillator
Recipe of Liquid Scintillator
Aromatic Solvent & Flour
WLS Gd-compound
LAB PPO +
Bis-MSB
0.1% Gd+TMHA
(trimethylhexanoic acid)
0.1% Gd compounds with CBX (Carboxylic acids; R-COOH)
- CBX : MVA (2-methylvaleric acid), TMHA (trimethylhexanoic acid)
CnH2n+1-C6H5 (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 : 147oC (PC : 48oC)• Environmentally friendly (PC : toxic)• Components well known (MO : not well known)• Domestically available: Isu Chemical Ltd. (
이수화학 )
Raw/MCRaw/MCDataData
ProductionProductionModulesModules
ReconstructionReconstructionModulesModules
UserUserAnalysisAnalysisModulesModules
UserUserntuplesntuples
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
RRENO AAnalysisnalysis CControlontrol
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
RENO Event Display
Calculation of Background Rates due to RadioactivityConcentration
40K (ppb) Concentration
232Th (ppb) Concentration
238U (ppb) 40K [Hz] 232Th [Hz] 238U [Hz]
Total [Hz]
Rock 4.33(ppm) 7.58(ppm) 2.32(ppm) 1.06 7.14 0.99 9.2
LS in Target 0.010 0.018 0.014 9.00 1.63 3.67 14.3
Target Contatiner 0.008 0.207 0.168 0.08 0.24 0.63 1.0
LS in Gamma Catcher 0.010 0.018 0.014 15.18 2.27 5.27 22.7
Gamma Catcher Container
0.008 0.207 0.168 0.07 0.17 0.63 0.9
LS in Buffer 0.010 0.020 0.005 0.77 0.16 0.14 1.1
Buffer Tank 0.06 0.9 0.9 0.03 0.10 0.20 0.3
PMT 13.6 208.5 49.4 2.50 5.23 2.99 10.7
Total ~60.2
Systematic Uncertainty Goals
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 0.0
Neutron capture (H/Gd ratio) 1.0 < 0.1
Capture energy containment 0.4 0.1
Neutron geode distance 0.1 0.0
Neutron delay 0.4 0.1
Positron-neutron distance 0.3 0.0
Neutron multiplicity 0.5 0.05
combined 2.7 < 0.5
Expected Number of Neutrino Events at RENO
• 2.73 GW per reactor ⅹ 6 reactors• 1.21x1030 free protons per targets (16 tons)
• Near : 1,280/day, 468,000/year• Far : 114/day, 41,600/year
3 years of data taking with 70% efficiency
Near : 9.83x105 ≈ 106 (0.1% error) Far : 8.74x104 ≈ 105 (0.3% error)
RENO Expected Sensitivity90% CL Limits Discovery Potential” (3)
10x better sensitivity than current limit
New!! (full analysis)
RENO Expected Sensitivity
GLoBES group workshop@Heidelberg – Mention’s talk
SK m2
Status Report of RENO RENO is suitable for measuring 13 (sin2(213) > 0.02)
RENO is under installation phase.
Geological survey and design of access tunnels & detector cavities are completed → Civil construction was finished in February, 2009.
International collaborators are being invited.
Data –taking is expected to start in mid 2010.
Buffer steel containers are installed.