Proposal for RENO-50
Soo-Bong Kim (KNRC, Seoul National University)
“International Workshop on RENO-50, June 13-14, 2013”
Overview of RENO-50
 RENO-50 : An underground detector consisting of 18 kton ultralow-radioactivity liquid scintillator & 15,000 20” PMTs, at 50 km away
from the Hanbit(Yonggwang) nuclear power plant
 Goals : - High-precision measurement of q12 and Dm221
- Determination of neutrino mass hierarchy
- Study neutrinos from reactors, (the Sun), the Earth,
Supernova, and any possible stellar objects
 Budget : $ 100M for 6 year construction
(Civil engineering: $ 15M, Detector: $ 85M)
 Schedule : 2013 ~ 2018 : Facility and detector construction
2019 ~
: Operation and experiment
Near Detector
Far Detector
RENO-50
10 kton LS Detector
~47 km from YG reactors
Mt. Guemseong (450 m)
~900 m.w.e. overburden
Funding
 1st attempt in 2012 : almost successful but failed
 Continuous attempts with organized efforts :
- Korea has significantly increased investments into the basic science.
- Korea established a new institute of IBS in 2012.
- Complete a conceptual design based on more detailed MC studies and
optimized detector design.
- Prepare a well-written proposal.
- Form international collaboration (LOI)
Technical Challenges
KamLAND
RENO-50
LS mass
~1 kt
18 kt
Energy Resolution
6%/E
3%/E
Light yield
250 p.e./MeV
>1000 p.e./MeV
 Large detector (18 ktons) : D=30m, H=30m
 3% energy resolution :
- High transparency LS : 15 m → 25 m (purification & better PPO)
- Large photocathode coverage : 34% → 67% (15,000 20” PMT)
- High QE PMT : 20% → 35% (Hamamatsu 20” HQE PMT)
- High light yield LS : ×1.5 (1.5 g/ℓ PPO → 5 g/ℓ PPO)
Expected Energy Resolution
PMT coverage : 67% (15,000 20” PMTs)
PMT coverage : 67% (15,000 20” PMTs)
+ Attenuation length : 25 m
+ QE : 35%
Conceptual Design of RENO-50
1000
1000 20”
10” OD
OD PMTs
PMTs
Water
Water
Mineral
Mineral Oil
Oil
LS
LS (18
(10 kton)
kton)
25 m
30
27 m
32
32 m
37
15000
15000 20”
10” PMTs
PMTs (67%)
(24%)
30
25 m
m
32
27 m
m
37
32 m
m
Physics Goals
 Precise measurement of q12, Dm221 and Dm231
 sin q 12
2
sin q 12
2
 1 . 0 % 1

(← 5.4%)
D m
Dm
2
21
2
21
 1 . 0 % 1

(← 2.6%)
D m
Dm
2
31
2
31
 1 . 0 % 1
(← 5.2%)
 Determination of mass hierarchy (sign of Dm231 or Dm232)
- Quite challenging : requires extremely good energy resolution
 Neutrino burst from a Supernova in our Galaxy
- ~5400 events (@8 kpc)
- A long-term neutrino telescope
 Geo-neutrinos : ~ 900 geo-neutrinos for 5 years
- Study the heat generation mechanism inside the Earth

Schedule
 2013
: Group organization
Detector simulation & design
Geological survey
 2014 ~ 2015 : Civil engineering for tunnel excavation
Underground facility ready
Structure design
PMT evaluation and order,
Preparation for electronics, HV, DAQ & software tools,
R&D for liquid scintillator and purification
 2016 ~ 2018 : Detector construction
 2019 ~
: Data taking & analysis
Your ideas and participation invited!