1. Sterile Neutrinos at the Crossroads, Blacksburg, VA
Status of RENO
Yeongduk Kim, Sejong University
On behalf of RENO collaboration
Sterile Neutrinos at the Crossroads, Blacksburg, VA

2. Contents Q13 measurement with reactor neutrinos RENO overview
Final Construction of RENO
Calibration Data of RENO
Summary

3. Reactor Neutrino Experiment at a Glanceν e + n Gd γ
~30μs
Delayed signal E å ~ 8
MeV g
prompt signal
Inverse Beta Decay
q13 Dominant
sin2(213)=0.04
sin2(213)=0.1
sin2(213)=0.2
E (MeV)
“near”
“far”
q12 Dominant

4. Reactor Sites Around the World
Two Reactor Sites
Multi-Reactor Sites
Under Consideration
Former Host Site
Jonathan Link, Columbia U Seminar
2003

5. RENO Sites Yonggwang Nuclear Power Plant
near detector site
46.1 m
95 m
reactor
detector m
294.3 m
~256 m
far detector site
168.1 m
272 m
Yonggwang Nuclear Power Plant
Six ~ 1 GWe class PWRs
Total average thermal power of 16.4 GW (max 17.3 GW)
Operational factor > 90%

6. RENO Detector 354 10” ID PMTs : 14% surface coverage 67 10” OD PMTs
Both PMTs : HAMAMATSU, R7081
Mu-metal shielding for each PMT. (-5cm)
No special reflector for ID
Tyvek reflector at OD
LAYER D
(cm) H
vessel
Filled with
Mass
(tons)
Target
280
320
Acrylic
Gd(0.1%) +LS
16.5
Gamma catcher
400
440 LS
30.0
Buffer
540
580
SUS
Mineral oil
64.4
Veto
840
880
Concrete
water
352.6

7. Milestones in 2011 Detector closing (Jan.)
Installation of electronics hut & control room (Feb.)
DAQ electronics & HV supplying system, & cabling (Feb.)
Installation of slow control & monitoring system (Jan. ~Jun.)
Liquid scintillator production & filling (May ~ Jul.)
Installation of 1D&3D calibration system (Jun..~ Aug.)
Installation of water circulation system (Jul. ~ Aug.)
Began regular data-taking & calibration (Aug. 1 ~)

8. Detector Construction & Closing (Jan. 2011)
Near : Jan. 21, 2011
Far : Jan. 24, 2011

9. Completed RENO Detector (Feb. 2011)
Liquid Scintillator Production System
DAQ Electronics
Calibration System
Control Room

10. Dry Run
Before filling liquids, we tested PMTs with a bottle of liquid scintillator & source at center.
QBEE threshold is set to 1 mV for data taking.
Charge(counts)
discri. thr.
-0.4mV -0.5mV -0.6mV -0.7mV -1.0mV
137Cs source
Liquid
Scintillator
1 Photoelectron peak

11. Gd-LS & LS Goal Gd-LS : 0.1% Gd , PPO 3g/L, bis-MSB 30mg/L  TARGET
LS : PPO 3g/L, bis-MSB 30mg/L  GAMMACATCHER
Concentrated Liquids
Gd-LAB : 0.5% Gd ( X5 concentration)
LS-Master : PPO 30 g/L, bis-MSB 300mg/L ( X10 concentration)
LS batch (2000L)
LAB (1800 L) + LS-Master (200L)
Near/Far separate production & filling
Gd-LS batch (2000L)
LAB (1400 L) + LS-Master (200L) + Gd-LAB (400L)
Produced in Far detector area and divided two

12. FAR NEAR LAB 10ton LAB 10ton GdLS LS (0.1 %) 2000L LS 2000L Water out
LS master
(x10)
200L
Gd-LAB
(0.5%)
400L
Gd-sol
TMHA LS
LAB
10ton
Water out
Divide into two
G.C.
FAR
LS master
(x10)
200L LS
2000L
LAB
10ton
Water out
G.C.
NEAR

13. LS handling system
Gd Loaded Liquid Scintillator

14. Liquids Production & Filling
Gd-LS filling for Target
Both near and far detectors are filled with Gd-LS, LS & mineral oil as of July 5, 2011.
Gd-LS(18805L, <0.2% difference)
Veto water filling is completed at the end of July, 2011.
DAQ Electronics
Gd Loaded Liquid Scintillator
LS filling for Gamma Catcher
Water filling for Veto

15. Water circulation system
veto
Circulation system
Drain
Local Water supply
Ultra-pure water system is important for VETO efficiency.
Solenoid valve : Auto on/off
Feedback from the ultrasonic level sensor of Water level

16. Gain matching of PMTs 137Cs source in the center.
PMT gains are set to 1.0x107 for all PMTs.
gain variation between PMTs are within 3% for both detectors.
Gain (107)
# of PMTs

17. Electronics & Trigger Software trigger
QBEE : each channel digitized if over threshold.
All the hits are sorted in time and grouped into an event if number of hits exceeds preset trigger condition. (ID:90, OD:10)
Pedestal hits are collected realtime
Intrinsic charge Injector into each channel for electronics calibration.
Types of Trigger : ID OD
LASER
PEDESTAL
Charge Injector
Data block(20ms)
Software trigger
200ns
“Software”
event
Merge the data
From front-end PCs
Number of hits exceeds the threshold,
Send downstream

18. Laser calibration system
Blue(420nm) Laser  Fiber optics Top, Barrel)
Optical Fiber+
Cosine Corrector
Barrel
Top
Bottom
Laser
Q (degree)

19. 1-D source driving systems
Two identical source driving systems at the center of TARGET and one side of GAMMACATCHER.

20. Calibration w/ Gammas 68Ge 137Cs 60Co Preliminary Far Near
1.022 MeV
0.662 MeV
Far
Near
60Co
2.506 MeV
center.
~ 230 PE/MeV
Near/Far show similar spectra.

21. 252Cf - neutron Preliminary Far Near
We are observing both Gd capture and hydrogen capture as expected by simulation.
Capture time distribution and vertex reconstruction is in progress.
Preliminary
Gd(n,g) neutron capture signal
p(n,g) neutron capture signal
Far
Near

22. Backgrounds – single rates.
Trigger Conditions :
BUFFER
No VETO
VETO
NEAR
~280 70
~533
FAR
~110 86
~66
Background trigger rates over ~0.5MeV is comparable to the simulated rates over 1MeV.

23. Backgrounds – single rates
Simulation(TDR)
Background events with All triggers.
Events/ (sec 65keV)
NEAR
FAR
3MeV

24. RENO Sensitivity on sin2(2q13)
Statistical errors (3 years of data taking with 70% efficiency)
Near : 9.83x105 ≈ (0.1% error)
Far : x104 ≈ (0.3% error)
T2K
Systematic error : <0.5%
* Sensitivity : sin2(2q13) > at 90% C.L.
90% CL Limits

25. Summary
Construction of both near and far detectors at RENO are completed in Feb
All the liquids are produced and filled by end of July 2011.
Regular data-taking with NEAR & FAR detectors began from August 1, 2011.
Data reduction, source calibration, and Monte-Carlo reconstruction efforts are on progress.
RENO group hope to tell the value of sin2(2q13) at the anticipated time.

27. Backup Slides

28. Comparison of Reactor Neutrino Experiments
Location
Power
(GW)
Distances
Near/Far(m)
Depth
Near/Far
(mwe)
Target Mass
(tons)
Double-CHOOZ
France
8.7
400/1050
60/300
10/10
RENO
Korea
17.3
290/1380
120/450
16/16
Daya Bay
China
17.4
360(500)/1985(1613)
260/910
402/80
Detail numbers should refer to individual experiment.

29. Calibration Sources type source E(keV) Activity (m Ci) calibration
gamma
137Cs
662 1
threshold e+
68Ge
1022
0.014
Position,
E threshold
60Co
2506( )
Multiple gamma
neutron
252Cf
Neutron+gammas
~8000
0.06
Neutron efficiency
Gd concentration

30. Sterile neutrinos at RENO
Both RENO detectors will see the deficit of neutrinos if sterile neutrinos exist.
No L/E sensitivity except 0.1 eV2

31. Slow Monitoring System
PMT HV Adjustment & Monitor (LABVIEW)
A1932 primary current & individual HV return value.
Detector Temperature (BUFFER, VETO)
PT-100 thermocouple.
Water Level
Using ultrasonic sensor.
Rn Monitoring
Sun Nuclear 1027 model.
Gas Concentration – CO2 & O2
KCD-HP500 : CO2 concentration measurement using IR absorption
Honeywell XCD : O2 concentration
Humidity & Temperature
HTM420R
IP Camera System

32. 1D system configuration
passive pulley
active(motor) pulley
glove box
source case
(acrylic)
weight
(teflon)
Mechanical system
wire pulley
(circumference ~ 1 m)
Control system