1. neutrino oscillation

1. Neutrino Oscillation

1

2

3

θ13

θ12

θ23

θ12

θ13

θ23

Gaol of RENO experiment = θ13


)(||| 2 P

νe

νe

νe

νe

νe

DistanceProb

abili

ty ν

e

disappearance


2. Neutrino Detecting

Pn

Prompt signalΣE ~ 1.022MeV

Delayed signalΣE ~ 7.96MeV

Neutron captured by Gadolinium

e~30μs

Gd

γe γ γ

γγ

γ

2. Neutrino Detecting

1 MeV 8 MeV6 MeV 10 MeV

Arbi

trar

y

Flux Cross Section

From Bemporad, Gratta and Vogel

▶ Expected measurable neutriron spectrum

▶ Prompt signal ▶ Delayed signal

2. Detector & Data taking #354 10” ID PMTs : 14% sur-face coverage #67 10” OD PMTs Both PMTs : HAMAMATSU, R7081

LAYERD

(cm)

H(cm) vessel Filled

withMass(tons

)

Target 280 320 Acrylic Gd(0.1%) +LS 16.5

Gamma

catcher

400 440 Acrylic LS 30.0

Buffer 540 580 SUS Mineral oil 64.4

Veto 840 880 Concrete water 352.

6

Radioactive Source div-ing

2. Detector & Data takingH V

Decou-pler

HV supply

Signal outQbee(DA

Q)Signal transform to Digi-tal

Raw Data1. Ch2. Time 3. Signal

size

RFM;root file

(reformat)

Online PC

Offline PC

PRDSelecting in-teresting in-formation

Reduc-tionSelecting neu-trino event

event

1 2 …ch 034 064 .

time . . .size . . .

ntuple formbinary

Calibration analysis

NPE table

3. Calibration

Calibration 3 stepQBEE calibration Gain matching Energy calibration E

Detector

Deposit Energy

PMT

Unknowing Energ[MeV] photoelectron current ADC count

Qbee

f(x)’

f(x)

f(x)’’

3. Calibration▶ QBEE Calibration imagine input charge(current) → output count : count pC(current)

f(x)

3. CalibrationPhotocathode : Alkali (1group) 2.xxeV work function

dynodes

electron multiplication1

2

3 nNel

E=hc/λ ~1240eV·nm/400nm ~3eV current

P M TpCC 6.110106.1 719

Ne=GainⅹNp.e

▶ Gain variation → regular checking

3. Calibration▶ Gain matching Single Photo-electron measurement

3. Calibration▶ Gain matching

<Coverage ~ 12.6%>

MeVepEQ

MeVep .250)2.0(~.126.0.10000~9000

pC p.e f(x)’

137Cs is satisfied with (354 PMT > p.e) condition

3. Calibration▶ Gain matching

pC p.e f(x)’

3. Calibration▶ radio active souce for Energy calibration

137Cs

FarNear

0.662 MeV

60Co

2.506 MeV


68Ge1.022 MeV


Gd(n,g) neutron capture signal

p(n,g) neutron capture signal

FarNear

2.2 MeV

7.96 MeV

Sources @ center. Near/Far show similar spectra.

3. Calibration▶ Energy calibration

p.e MeV f(x)’’

PE to MeV Function(p2*X2+p1*X+p1)

3. Calibration

▶ Detector stability

Change p.e/MeV

4. MC simulation▶ RENO MC simulation : based on GLG4SIM geant 4 program. derived from KLG4SIM of KamLAND collaboration.

4. MC simulationMC_single PMT p.e distribution

Real_data_single PMT p.e distribution

4. MC simulation

4. MC simulation▶ Upgrading MC

4. MC simulation▶ Cs-137 MC

4. MC simulation▶ Ge-68 MC

4. MC simulation

Cs-137 : 1.7% Ge-68 : 3.2%

Co-60 : 1.6%

▶ Reduced Energy

5. Results▶ Improvement tuning

Cs-137 Ge-68 Co-60

5. Results▶ Improvement Energy calibra-tion

summary▶ To get energy information, we have to do calibration process

1. Qbee calibraiton 2. Gain matching 3. Energy calibration

▶ Upgrading MC for radioactive source data Application for capslue & container

Back up

1. Neutrino Oscillation)(||| 2

P

Pth : Reactor Thermal power f : Fission fraction of each isotope (reactor core simulation of Westinghouse ANC, and has error U235: 3.3%, Pu239: 4%, U238: 6.5%, Pu241:11%)ϕ : Interacted Neutrino Spectrum of each fission isotopeE : Energy released per fission

thPN

Arbi

trar

y

Flux Cross Section

From Bemporad, Gratta and Vogel

The observable antineutrino spectrum is the product of the flux and the cross section

The most probable neutrino energy interacting at a detector is 3.8 MeVThe cut-off at 1.8 MeV is due to the minimum neutrino energy required for IBD event.

Expected measurable neutriron spec-trum

Expected S1 & S2 spectrum

(1 MeV 2γ’s) + (e+ kinetic energy), E = 1~10 MeV

1 MeV 8 MeV

6 MeV 10 MeV

e p e+ + n (prompt) + p D + (2.2 MeV) (delayed) + Gd Gd* Gd + ’s(8 MeV) (delayed)

n+p→D+ γ(2.2MeV), n+Gd→Gd+γ’s(8MeV)

It happens that in the beta decay of 137Cs, the product barium nu-cleus is left in an "excited" state. This decays in a few minutes back to the "ground" state of the barium nucleus, emitting a pho-ton of fairly high energy, which is a "gamma" rays of energy 0.66 MeV.

Radioactive Sources 137Cs

0.66 MeV ↑

Radioactive Sources 60Co

Multiple Gamma =2.506 MeV

Germanium-68 decays by pure electron capture (EC) to the ground state of 68Ga with a half-life of 270.95(16) d. Gallium-68 in turn decays with a half-life of 67.71(9) min by a combination of EC and positron emission primarilyto the ground state of 68Zn.

stopped positron signal using 68Ge source→positron threshold

Radioactive Sources 68Ge

Radioactive Sources 252CfWhen a 252Cf nucleus spontaneously fssions, it emits on aver-

age 4 neutrons and approximately 20 low energy gamma rays. These ssion neutrons are used to calibrate the neutron detection efficiency.

Detector Stability

Cs137 Co60

Holder : Poly(methyl methacrylate) 밀도 1.18g/cm3

Cover : Epoxy 라고만 나옴

: Cs137 과 Co60 은 같은 모양입니다 .

Epoxy

Radioactive materials

Label

< 단면 >25.4mm

4.445mm

Holder

6.35mm

0.508mm

Ge68

Source : 밀도 9 mg/cm2 , 두께 0.254mm 의 aluminumized Mylar(polyester) disk 에 3mm 지름으로 deposit 됨

Cover : 1. 밀도 0.9 mg/cm2, 두께 ( 안나옴 ) 대략 0.25mm 의 polyimide Film(Kapton)

2. 밀도 , 두께 안나옴 Decal(film 종류 ) // film 개념이라 두께에 대한 정보가

없는듯함 사진에 흰색 Label 지가 Decal 같음

Retaing Ring : 제질 안나옴 Aluminum Holder : aluminum

Disk 총 두께 ~ 0.76mm 지름 = 23.8mm

3mm

~ 알루미늄 hodler 얇은 부분 0.4mm

40mm

3mm( 두께 )

20mm

8mm( 뚜껑두께 )

원 근거리 소스 아크릴 원통

3mm( 밑 부분 두께 )

4mm

20mm 정육각형8mm( 뚜껑두께 )

4mm

3mm

7mm

호의 길이 20mm

8mm2mm

뚜껑 위면뚜껑 단면

ConvolutionsImagine that we try to measure a delta function in some way …

Despite the fact that the true signal is a spike, our measuring system will al-ways render a signal that is ‘instrumentally limited’ by something often called the ‘resolution function’.

True signal Detected signal

True signal Convolved signal

Resolutionfunction

If the resolution function g(t) is similar to the true signal f(t), the output function c(t) can effectively mask the true signal.

http://www.jhu.edu/~signals/convolve/index.html

http://www.jhu.edu/~signals/convolve/index.html

Convolutions

3. CalibrationPhotocathode : Alkali (1group) 2.xxeV work function

dynodes

electron multiplication1

2

3 nNel

E=hc/λ ~1240eV·nm/400nm ~3eV current

P M TpCC 6.110106.1 719

Ne=GainⅹNp.e

1. neutrino oscillation

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