Gioacchino Ranucci INFN – Milano On behalf of the JUNO ......Gioacchino Ranucci INFN – Milano On...

Status and prospects of the JUNO experiment

Gioacchino RanucciINFN – Milano

On behalf of the JUNO Collaboration

London – Neutrino 2016July 6, 2016

• Determination of the neutrino mass hierarchy with a large mass liquid scintillation detector located at medium distance –few tens of km – from a set of high power nuclear reactors

• Precise measurements of oscillation parameters

• Additional astroparticle program

• Requirements, technical features and status of the experiment

Neutrino 2016 - July 6, 2016 Gioacchino Ranucci - INFN Sez. di Milano 1

JUNO physics summaryDaya Bay &Reno&DC 53 km

JUNO

KamLAND 20 kton LS detector ~3 % energy resolution-the

greatest challenge Rich physics possibilities

Mass hierarchy Precision measurement

of 3 mixing parameters Supernovae neutrino Geoneutrino Sterile neutrino Atmospheric neutrinos Nucleon Decay Exotic searches

Neutrino 2016 - July 6, 2016 Gioacchino Ranucci - INFN Sez. di Milano

Neutrino Physics with JUNO, J. Phys. G 43, 030401 (2016)

2

– LS large volume: for statistics– High Light(PE) for energy resolution

A large LS spherical detector


JUNO has been approved in China in Feb. 2013 ~ 300 M$

Prospective and approved funding from other countries:

• Belgium• Czechia• Finland• France• Germany• Italy• Russia• Taiwan• Chile

Steel Truss

Holding PMTs~17000 x 20”~34000 x 3”

Acrylic Spherefilled with 20 kt LS

3

Location of JUNONPP Daya Bay Huizhou Lufeng Yangjiang Taishan

Status Operational Planned Planned Under construction Under constructionPower 17.4 GW 17.4 GW 17.4 GW 17.4 GW 18.4 GW

Yangjiang NPP

Taishan NPP

Daya Bay NPP

HuizhouNPP

LufengNPP

53 km53 km

Hong KongMacau

Guang Zhou

Shen Zhen

Zhu Hai

2.5 h drive

Kaiping,Jiang Men city,Guangdong Province

Previous site candidate

Overburden ~ 700 m by 2020: 26.6 GW


JUNO Collaboration

Neutrino 2016 - July 6, 2016

BNUCAGSCQ UCIAEDGUTECUST

Guangxi UHIT

IHEPJilin U

Jinan U.

Nanjing UNankai U

Natl. CT UNatl. Taiwan UNatl. United U

NCEPUPekin U

Shandong UShanghai JTU

Sichuan USUT

SYSUTsinghua

UCASUSTC

U. of S. ChinaWuhan UWuyi U

Xiamen UXi'an JTU

Asia (31)

Europe (27)

France (5)APC ParisCPPM MarseilleIPHC StrasbourgLLR ParisSubatech NantesFinland (1)U OuluCzech (1)Charles U

Germany (7)FZ JulichRWTH AachenTUMU HamburgIKP FZI JülichU MainzU TuebingenBelgium (1)ULBAmenia (1)YPI

Italy (8)INFN CataniaINFN-FrascatiINFN-FerraraINFN-MilanoINFN-BicoccaINFN-PadovaINFN-PerugiaINFN-Roma 3Russia (3)JINRINR MoscowMSU

Observers (7):HEPHY Vienna

PUC BrazilJyvaskyla U. Finlan

UFA BrazilCENBG FranceUTFSM Chile

IMP CAS China America (4) PCUC – BISEE ChileMaryland U.- 2 groups

5

Approach to infer the Mass Hierarchy

The determination of the mass hierarchy relies on the identification on the positron spectrum of the “imprinting” of the anti-νe survival probability

Detection through the classical inverse beta decay reaction

++→+ enpν Eν>1.8 MeV

The time coincidence between the positron and the γ from the capture rejects the uncorrelated background

The “observable” for the mass hierarchy determination is the positron spectrum It results that Evis(e+)=E(ν)−0.8 MeV


MH and Survival probability

Or to make the effect of the mass hierarchy explicit, exploiting the approximation ∆m2

32 ≈∆m231 :

+ NH- IH

The big suppression is the “solar” oscillation → ∆m2

21 , sin2θ12The ripple is the “atmospheric” oscillation → ∆m2

31 from frequency MH encoded in the phase“high” value of θ13 crucial

arXiv 1210.8141

Method from Petcov and Piai, Physics Letters B 553, 94-106 (2002)


Neutrino & Positron Spectra

Conditions for the exampleThree neutrino framework (no effective ∆mee ∆mµµ)Baseline: 50 kmFiducial Volume: 5 ktThermal Power: 20 GWExposure Time: 5 yearsmore pessimistic than the true JUNO values

Positron visible energyE(vis) ~ E(ν) – 0.8 MeVAssuming 3% / sqrt(E) resolution Assuming negligible constant term in resolution

Normal HierarchyInverted Hierarchy

Spectrum in term of neutrino energy –no energy resolution

Spectrum in term of positron visible energy – folded with energy resolution → the challenge of the experiment


PRD 88, 013008 (2013) Relative Meas. ∆m𝜇𝜇𝜇𝜇2 from LBL Expts

Statistics only 4σ 5σ

Realistic case 3σ 4σ


Summary of MH Sensitivity

Gioacchino Ranucci - INFN Sez. di Milano

Baseline: 53 kmFiducial Volume: 20 ktThermal Power: 36 GWExposure Time: 6 yearsProton content 12% en. res. 3%

9


Precision Measurements

Statistics

+BG+1% b2b+1% EScale+1% EnonL

sin2 θ12 0.54% 0.67%

Δm221 0.24% 0.59%

Δm2ee 0.27% 0.44%

0.16%0.24% 0.39%0.54%0.16%0.27% E resolution

Probing the unitarity of UPMNS to ~1%more precise than CKM matrix elements !

Correlation among parametersGioacchino Ranucci - INFN Sez. di Milano 10


Supernova burst neutrinos

Diffuse supernova neutrinos

Solar neutrinos

Atmospheric neutrinos

Geo-neutrinos

Sterile neutrinos

Nucleon decay

Indirect dark matter search

Other exotic searches

Vast physics reach beyond Reactor Neutrinos

Gioacchino Ranucci - INFN Sez. di Milano

Neutrino Physics with JUNO, J. Phys. G 43, 030401 (2016)

11

Ground breaking in Jan. 2015 900 m slope tunnel

excavated out of 1340 m 330 m vertical shaft excavated out of

611 m

Schedule:Civil preparation：2013-2014 Civil construction：2014-2017Detector component production：2016-2017 Detector assembly & installation：2018-2019 Filling & data taking：2020


Progresses of the excavation

13P1.011, JUNO underground facilities and construction status, Xiaonan LiNeutrino 2016 - July 6, 2016 Gioacchino Ranucci - INFN Sez. di Milano

Central detector Acrylic sphere+ 20kt Liquid Scin+~17000 20” PMT+~34000 3’’ PMTWater Cherenkov~2000 20’’ PMT

Top Tracker

Calibration

44.5m

D43.5m

Acrylic Sphere: ID35.4m Stainless Steel Truss: ID40.1m

ElectronicsFilling + Overflow

Detector's dimensions and layout finalized


P3.050, Central detector of JUNO, Yuekun Heng

`

Very high photocathode density (~78% coverage like SNO)Targeted the largest light level ever detected in LLSD ~1200 pe/MeV

(Daya Bay 160 pe/MeV - Borexino 500 pe/MeV - KamLAND 250 pe/MeV)

Central detector distinctive feature: resolution

15

Considerations on resolution

Detector Resolution:

a - stochastic term3% resolution at

1MeV is pivotal

Entr

ies (

a.u.

)

2Positron Energy [MeV]

3 4 5 61

3% Res

Central Detector design optimised for Mass Hierarchy: “Precise & Large”

Maximise detected light

b,c - non-stochastic terms Controlsystematics

Large photocoverageTransparent Scintillator

High QE

Small (3”) PMTsCalibration

iso-Δχ2 contours

J.Ph

ys. G

43 (2

016)

no.

3, 0

3040

1

16P3.063, Double calorimetry in liquid scintillator neutrino detectors , Miao He

Evaluate both the PMT characteristics’ impacts on MH hierarchy and the cost.

Finished 20” PMT bidding at end of 2015:-- 15000 MCP-PMT(NNVT)-- 5000 Dynode-PMT (Hamamatsu)

Recent milestone: choice of PMT types

Neutrino 2016 - July 6, 2016 Gioacchino Ranucci - INFN Sez. di Milano18

P1.012, The R&D of 20 inch MCP-PMTs for JUNO, Sen Qian

Forming panel size: 3m x 8m x 120mm

Prototype of spherical panel

The problems of shrinkage and shape variation were resolved.Three companies had good practices.

Acrylic divided into 200+ panels

Neutrino 2016 - July 6, 2016 Gioacchino Ranucci - INFN Sez. di Milano19


ADUAnalog to

Digital Unit

GCUGlobal

Control UnitPMT H V 100m cable

(data,LV,clock)BEC

wet dry

20

P1.014, JUNO PMT system and prototyping test, Zhimin Wang

Muon Veto Design

Water Cherenkov

20kt ultra-pure water

Water acting as moderator & pool instrumented to detect Cherenkov light

2000 20” PMTs located as in the picture

Optimize detection efficiency of Cherenkov light

Muon Veto: critical to reduce backgrounds

Cosmogenic isotopes rejection: reconstruction of muon tracks + 𝒪𝒪(1s) veto surrounding the track

Neutron Rejection: passive shielding (water) + time coincidence w/ muon + multiple proton recoils

Gamma rejection: passive shielding (water) Magnetic FieldCompensating Coil

21

Muon Veto DesignTop Tracker

Using OPERA plastic scintillator (49m2/module)Three layers to ensure good muon trackingPartial coverage due to available modules• Reject ~50% muons• Provide tagged muon sample to study

reconstruction and background contamination with central detector

P1.078, The design of the JUNO veto system, Haoqi Lu Eric Baussan

22

Tracker removal at Gran Sasso

Al2O3column

LAB and Al2O3 mixing tank

Pure LAB

Optical : >20m A.L @430nm? Radio-purity: 10-15 g/g (U, Th) ?

Determine the choice of sub-systems Al2O3 column, distillation, gas striping, water

extraction

Al2O3 column pilot plant installedin Daya Bay LS hall

Distillationsystem

Steamstripping

system

Distillation and steam stripping system

Installed at Daya Bay

Purify 20 ton LAB to test the overall design of purification system at Daya Bay. Replace the target LS in one detector

Quantify the effectivities of subsystems



Overall LAB5 view at Daya Bay

24

P3.051, The liquid scintillator system of the JUNO, Li Zhou

Many other ongoing tasks• Calibration:

– guided source insertion, LED, laser, CCD, …• Electronics, cable，box,… for the 3” PMT • LS filling• Slow control

– PMT, water, environmental monitoring & control• DAQ: crates, server, router, software, …• Offline farm, data storage/data center, software, …• Radioactivity measurements and screening • Development of MC and analysis tools• …


P1.013, A highly-integrated receiver chip with an automatic baseline regulation for JUNO, Pavithra Muralidharan et alP1.078, Radioactivity evaluation and control for the JUNO detector components and materials, Jie ZhaoP3.049, Measurement of the fluorescence quantum yield of bis—MSB, Xuefeng DingP4.004, Atmospheric neutrinos in JUNO, Wanlei GuoP4.085, Supernova Neutrino Observation at JUNO, Liangjian Wen

25


ConclusionThe vast potential physics reach of very large liquid scintillator detectors - MH determination and beyond – is the foundational motivation of JUNO conceived and planned to mark significant breakthroughs for the ultimate quest of the neutrino properties

The Collaboration is rapidly progressing toward the construction of the detector with all the important design decisions already taken, the prototyping phase marking important steps forwards for all the subsystems and with the excavation of the site going ahead

The JUNO exciting science program will start in 2020 when the experiment will be filled

Thank you!Gioacchino Ranucci - INFN Sez. di Milano 26

Gioacchino Ranucci INFN – Milano On behalf of the JUNO ......Gioacchino Ranucci INFN – Milano On...

Documents

Transcript of Gioacchino Ranucci INFN – Milano On behalf of the JUNO ......Gioacchino Ranucci INFN – Milano On...