Astroparticle physics in DUNE with the X-Arapuca detectors
Claudia Brizzolari (on behalf of the DUNE collaboration)
TAUP 2021
17th International Conference on Topics in Astroparticle and Underground Physics
26 August 2021 – 3 September 2021
The DUNE experiment
Deep Underground Neutrino Experiment
• CP violation in the neutrino sector
• neutrino mass hierarchy
• supernova neutrino bursts
• proton decay
Far Detector
Detector at SURF: 4 LArTPC 70 kton mass in total, 40 kton fiducial mass in total.
Two prototypes for the LArTPC, Single Phase (SP) and Dual Phase (DP), were tested at CERN.
Prototypes @CERN (ProtoDUNE) The underground layout of the SURF laboratory. The two main caverns each hold two 10 kton modules.
SP DP
Data room
LArTPCs
Single Phase technology
Charge detection Photon detection
LArTPC
• Horizontal drift 3.5m
• Wrapped-wire readout
Dichroic filters, WLS plates and SiPM read-out. Placed in the Anode Plane Assemblies (APA).
The PDS impact on the physics of DUNE
• Improve the energy resolution of the reconstructed energy of a Supernova neutrino burst event
• Provide fine time information for the measurement of the neutrino burst time profile
• Rejection of proton decay background
Photon detection system:
X-ARAPUCA
Reflective box equipped with an entrance window, two photon downshifting stages, one dichroic filter and one light guide coupled to SiPMs.
ARAPUCA: efficiencies in ProtoDUNE
Muon beam Electron beam
Efficiency of the cell from the detected-to-incident ratio.
Cells with double size but equal number of photosensors
Results published in B. Abi et al, First results on ProtoDUNE-SP liquid argon time projection chamber performance from a beam test at the CERN Neutrino Platform, 2020, JINST, vol. 15, issue 12, P12004
X-ARAPUCA: SiPM ganging and test in Xenon doped LAr
Ganging achieved (S/N>4)
in November in a table-top design (Hamamatsu) and in January (FBK) All measurents at 77 K
Test of X-Arapuca detectors in LAr doped with Xenon. Special run in ProtoDUNE-SP
X-ARAPUCA: PVT vs PMMA WLS bar tests
PVT
PVT PMMA
PMMA Equipping the X-Arapuca with the FB118 (PMMA based,
developed in Milano-Bicocca) as secondary wavelength shifter instead of the EJ-286 (PVT based, developed by Eljen) increases the PDE by ~50%
Results published in arXiv:2104.07548, submitted to JINST
Current Scientific Requirements
•
Time Resolution < 1 μs and avg Light Yield> 20 PE/MeV, based on Supernova events
• Light Yield minimum
> 0.5 PE/MeV, based on nucleon decay events
SP and PDS performances for Supernova Neutrino Bursts
Main channel (+ interaction and ES on electrons)
Counting: counting only trigger Shape: energy weighted scheme, TPC based (SP)
Expected spectrum
Expected spectrum in 40 kton LAr, 10 kpc for electron capture Supernova (no
oscillations assumed)
Expected measured spectrum after
detector response smearing
νe flavor dominates
Energy and time resolution
Electron drift corrected with information from PDS, resolution improved
Event timing provided by both TPC and PDS. First 50 ms of 10-kpc distant supernova mean interval between
neutrino interactions: 0.5-1.7 ms TPC: time resolution 0.6 ms PDS: time resolution < 1 μs
Corrected for drift attenuation
PDS performances for nucleon decay
PE/MeV in
the volume Mis-ID Rate at CPA (%)
0.09 6.2 ± 0.4
0.11 5.0 ± 0.4
0.16 3.2 ± 0.4
0.28 2.3 ± 0.4
0.33 1.6 ± 0.2
0.50 1.1 ± 0.2
LArTPC sensitive to SUSY favored mode
Conclusions
• Working principle of Photon Detection System validated in ProtoDUNE.
Final design validated with lab tests, final test in ProtoDUNE run II
• Possible improvement in WLS PDE (~50%)
• Avg light yield for the PDS: >20 PE/MeV
• LArTPC is the only future prospect for a large, cleanly tagged Supernova νe component.
Time resolution of < 1 μs.
• Proton decay trigger efficiency >99%
Minimum light yield 0.5 PE/MeV at CPA
