GERDA, MAJORANA and LEGEND - towards a background-free ton-scale Ge-76 experiment - INDICO-FNAL

Page created by Rita Delgado
 
CONTINUE READING
GERDA, MAJORANA and LEGEND - towards a background-free ton-scale Ge-76 experiment - INDICO-FNAL
GERDA, MAJORANA and LEGEND
    towards a background-free
   ton-scale Ge-76 experiment
                Yoann KERMAÏDIC
  for the GERDA, MAJORANA and LEGEND collaborations

                    XXIX International Conference
                      on Neutrino Physics

                         Virtual meeting
                         July 2020
GERDA, MAJORANA and LEGEND - towards a background-free ton-scale Ge-76 experiment - INDICO-FNAL
Physics case: neutrinoless !! decay
                         Search for a natural double beta decay
               without the standard emission of two anti-neutrinos (0#!!)
                                     n

                           n

                           n                                         p
                                                                           $%
                                                  ?
                                                                           $%
                           n                                        p

                  0#!! decay is a search for lepton number violation:
                    ☞ sheds light on Majorana nature of neutrinos
               ☞ tests theories with lepton number violating interactions
                       ☞ constrains baryon asymmetry scenarios

                  !! decay is energetically favoured in many isotopes:
                        76Ge – 82Se – 100Mo – 130Te – 136Xe – …
01 July 2020                   Neutrino2020 conference - 76Ge 0vbb decay        2
GERDA, MAJORANA and LEGEND - towards a background-free ton-scale Ge-76 experiment - INDICO-FNAL
0#!! experimental signature in 76Ge

                                            Counts /(keV.kg.yr)

                                                                                                                 Counts /(keV.kg.yr)
R (T=U)

                                                                                                                                       0.06
          X = @A                                                                                                                       0.04
                                                                       1
                                                                                                                                       0.02
                        26.3 h                                                                                                           0     1800   1900          2000
                                                                                                                                                                       Energy (keV)
                        EF
                        DDAs
                                                                       -1

          ?×OP?O Q
                                                                  10

    2                            !%
               @A
               >?
GERDA, MAJORANA and LEGEND - towards a background-free ton-scale Ge-76 experiment - INDICO-FNAL
Outline
                                                                        76
                                                                            Ge (88% enr.)
                                              1030

                                                                                                                                long-term
        LEGEND                                1029
                                                                                                                                M ton
         1000                                                                                                                   XNY
                                                                                                                                 M/= > MN
                                                                                                                                          =[ yr
                                              1028
                         T1/2 3s DS [years]

          LEGEND                                                                                                                mid-term
                                              1027
            200                                                                                                                 =NN kg
                                                                                                                                XNY
                                                                                                                                 M/= > MN
                                                                                                                                          => yr

                                              1026                                                   IO mmin
                                                                                                         bb
                                                                                                             range
           GERDA                                                                                     Background free
          MAJORANA                                                                                   0.1 counts/FWHM-t-y
                                                                                                                                running/ended
                                              1025                                                   1.0 count/FWHM-t-y          MN
                                                                                                                                          =? yr

                                              1024 -3
                                                        10-2        10-1
                                                                                                                            3
                                                10                                  1           10         102             10
                                                                           Exposure [ton-years]

     1.        Status of MAJORANA and GERDA data taking
                                                                                                                new results
     2.        Joint worldwide community: LEGEND                                                            at this conference!
     3.        Prospective towards a ton-scale experiment
01 July 2020                                            Neutrino2020 conference - 76Ge 0vbb decay                                                 4
GERDA, MAJORANA and LEGEND - towards a background-free ton-scale Ge-76 experiment - INDICO-FNAL
MAJORANA DEMONSTRATOR

      Searching for neutrinoless double-beta decay
        of 76Ge in HPGe detectors and additional
           physics beyond the standard model

 Source & Detector: Array of p-type, point contact
 detectors
  29.7 kg of 88% enriched 76Ge crystals
 Excellent Energy resolution: 2.5 keV FWHM @ 2039 keV
 Low Background: 2 modules within a compact graded
 shield and active muon veto using ultra-clean materials

               Operating underground at the 4850’ level of the Sanford Underground Research Facility since 2015

01 July 2020                             Neutrino2020 conference - 76Ge 0vbb decay                                5
GERDA, MAJORANA and LEGEND - towards a background-free ton-scale Ge-76 experiment - INDICO-FNAL
MAJORANA DEMONSTRATOR 2019 0νββ Result

  Operating in a low background regime and benefiting from excellent energy resolution

                                                                                      Initial Release:
                                                                                          9.95 kg-yr open data
                                                                                          PRL 120 132502 (2018)
                                           26 kg-yr
                                                                                      Latest Release:
                                                                                         First unblinding of data
                                                                                         26 kg-yr exposure
                                                                                          PRC 100 025501 (2019)

                                                                                      Median T1/2 Sensitivity:
                                                                                        4.8 × 1025 yr

                                                                                      Full Exposure Limit:
                                                                                         T1/2 > 2.7 × 1025 yr (90% CL)

                                                                                      Background Index at 2039 keV
                                                                                      in lowest background config:
                                                                                          11.9 ± 2.0 cts/(FWHM t yr)
     Latest result from 26 kg-yr (data up through April 2018)
     An upcoming result with improved analysis and new data through Nov 2019
         A combined total of ~50 kg-yr, a release later this summer
     Upcoming new results on background model & beyond the standard model searches
     A new result on excited state decays of 76Ge
01 July 2020                              Neutrino2020 conference - 76Ge 0vbb decay                                 6
GERDA, MAJORANA and LEGEND - towards a background-free ton-scale Ge-76 experiment - INDICO-FNAL
MAJORANA: Progress and Improvements

               Progress towards modeling the measured background                                        Low-Background Datasets

                                                                                                                                      M. Buuck, UW, PhD
                                                                                                                                       Dissertation 2019
                                                                                                              Enriched Detectors
Investigating source of excess backgrounds near Qββ                                                                DCR Cut Only
   Preliminary findings point to 232Th backgrounds
distant from the array
   A higher fidelity modeling of distant components is underway
                         See Poster 257: An Improved Background Model for the
                         MAJORANA DEMONSTRATOR (A. Reine, C. Haufe)

 An upcoming result with improved analysis and new data through Nov 2019
          A combined total of ~50 kg-yr, a release later this summer

Improved analysis
  Improved energy estimator with a corrected waveform start time
    Excellent energy resolution (2.5 keV FWHM at Qββ)                                                                         ± 0.2 keV
    and improved linearity
  Enhanced the stability and uniformity of background rejection parameters
    Improved discrimination power of the multisite (AvsE)
    and surface alpha (DCR) cuts
                                             See Poster 586: Status and Results from the MAJORANA DEMONSTRATOR
Status and run plan                          Experiment (J. M. López-Castaño, N. Ruof, A. Hostiuc)

   2020 hardware upgrade
     Improved the robustness of the signal and HV connections based                                        New connectors
    on an ultra-clean, low-mass, & high-reliability design
     Deployment of larger inverted-coax point-contact detectors and
    measure performance
   Final running to yield an ultimate integrated exposure of ~60 kg-yr
01 July 2020                               Neutrino2020 conference - 76Ge 0vbb decay                                                                       7
GERDA, MAJORANA and LEGEND - towards a background-free ton-scale Ge-76 experiment - INDICO-FNAL
MAJORANA: Beyond the Standard Model Searches
       The low backgrounds, low threshold, high resolution spectra allows additional physics searches
         Controlled surface exposure of enriched material to minimize cosmogenics

      Upcoming updates to beyond the standard model searches

    Excellent energy resolution: 0.4 keV FWHM at 10.4 keV                       Low-energy physics
      Progress towards a low-E background model:                                searches
                                                                                   pseudoscalar dark matter
                                                                                   vector dark matter,
               65Zn                                                                                            PRL 118 161801 (2017)
                                PRELIMINARY                  Best Fit
                                                                                   14.4-keV solar axion
        55Fe

                      68Ge

                                                                                   Updated limits to be        C. Wiseman, J. Phys. Conf.

                                                                        210Pb
                                                                                released after unblinding       Ser. 1468, 012040 (2020)

               3H
                                                                                Search for tri-nuclean decay
                                                                                   A test of baryon number      PRD 99 072004 (2019)
                                                                                violation

                                                                                 Lightly ionizing particles
                                                                                    First limit for charge     PRL 120 211804 (2018)
                                                                                 as low as e/1000

                Low energy spectra from 14.9 kg-yr of low-
                background open physics running (DS1-6a)

01 July 2020                                  Neutrino2020 conference - 76Ge 0vbb decay                                                     8
GERDA, MAJORANA and LEGEND - towards a background-free ton-scale Ge-76 experiment - INDICO-FNAL
New Result: Double Beta Decay to Excited States
                                                    Forthcoming arXiv preprint

  An inherently multi-site signal topology:
    A “source” detector will have a broad energy
  spectrum from ββ
    The “gamma” detector will measure energy
    peaked at the γ energies
             41.9 kg y of isotopic exposure
             (20.6 kg y of which was blinded)

                                                             The most stringent limits to date for ββ to each excited
                                                             state of 76Se due to:
                                                                 Operating an array in vacuum: high detection efficiency
     See Poster 254: New results from Majorana
     Demonstrator’s search for Double-Beta Decay                 Exquisite energy resolution for identifying peaks
     of 76Ge to Excited States of 76Se (I. Guinn)                Low environmental backgrounds & analysis cuts
01 July 2020                                  Neutrino2020 conference - 76Ge 0vbb decay                                    9
GERDA, MAJORANA and LEGEND - towards a background-free ton-scale Ge-76 experiment - INDICO-FNAL
GERDA at Laboratori Nazionali del Gran Sasso in Italy
                                                                                GERDA Collaboration meeting
                                                                                         Zurich, Switzerland
                                                                                                  June 2019

       http://www.mpi-hd.mpg.de/gerda/                                                  INR
                                                                                        Moscow
                                                                                            ITEP
                                                                                            Moscow

                  European Commission                                                       Kurchatov
                  Joint Research Centre                                                     Institute
                  JRC Geel

About 100 scientists
from Europe

01 July 2020                              Neutrino2020 conference - 76Ge 0vbb decay                            10
Background-free experiment design
[Eur. Phys. J. C (2018) 78:388]

     • signal topology
                                                                      Pure water
                                                               Liquid Ar

!! decay signal:
single-site event
energy deposition                                        HH
in a 1 mm3 volume                                                             PMT

                                                                  Optical
                                                                  fibers

                                                   #       #
01 July 2020                      Neutrino2020 conference - 76Ge 0vbb decay         11
Background-free experiment design
[Eur. Phys. J. C (2018) 78:388]

     • background mitigation
                                                                      Pure water
                                                               Liquid Ar

!! decay signal:
single-site event
energy deposition                                        HH
in a 1 mm3 volume                                                             PMT

                                                                                       Muon veto based on
                                                                  Optical
                                                                  fibers               Cherenkov light and
                                                                                       plastic scintillator
                                                                                   \
                                                   #       #
01 July 2020                      Neutrino2020 conference - 76Ge 0vbb decay                                   12
Background-free experiment design
[Eur. Phys. J. C (2018) 78:388]

     • background mitigation
                                                                      Pure water
                                                               Liquid Ar
                                                ]

!! decay signal:
single-site event
energy deposition                                        HH                            LAr veto based on Ar
in a 1 mm3 volume                                                             PMT      scintillation light read
                                                                                       by fibers and PMT

                                                                                       Muon veto based on
                                                                  Optical
                                                                  fibers               Cherenkov light and
                                                                                       plastic scintillator
                                                                                   \
                                                    #      #
01 July 2020                      Neutrino2020 conference - 76Ge 0vbb decay                                   13
Background-free experiment design
[Eur. Phys. J. C (2018) 78:388]

     • background mitigation
                                                                      Pure water
                                                               Liquid Ar
                                                ]

                                                                                       Ge detector
!! decay signal:                                                                       anti-coincidence
single-site event
energy deposition                  ]                     HH                            LAr veto based on Ar
in a 1 mm3 volume                                                             PMT      scintillation light read
                                                                                       by fibers and PMT

                                                                                       Muon veto based on
                                                                  Optical
                                                                  fibers               Cherenkov light and
                                                                                       plastic scintillator
                                                                                   \
                                                    #      #
01 July 2020                      Neutrino2020 conference - 76Ge 0vbb decay                                   14
Background-free experiment design
[Eur. Phys. J. C (2018) 78:388]

     • background mitigation
                                                                                       Pulse shape
                                                                      Pure water       discrimination (PSD)
                                                               Liquid Ar               for multi-site and
                                                ]                                      surface ^, ! events

                                                                                       Ge detector
!! decay signal:                                                                       anti-coincidence
single-site event
energy deposition                  ]                     HH                            LAr veto based on Ar
in a 1 mm3 volume                                                             PMT      scintillation light read
                                                                  H                    by fibers and PMT
                                    ]
                                                    _
                                                                                       Muon veto based on
                                                                  Optical
                                                                  fibers               Cherenkov light and
                                                                                       plastic scintillator
                                                                                   \
                                                    #      #
01 July 2020                      Neutrino2020 conference - 76Ge 0vbb decay                                   15
The phase II Ge detector array
LAr veto optical fibers              Coaxial detector

                                                  Low-mass holders

                                                                                             Strings assembly

Low-mass contacts                    BEGe detector ~0.7 kg
•   Up to 41 enriched detectors deployed from Dec. 2015 to Dec. 2019
•   Three detectors type (Coaxial, BEGe and IC)
•   Two data taking periods with an upgrade in May 2018 in between
•   Total enriched detectors mass: 35.6 kg/44.2 kg                              Inverted Coaxial det. ~1.8 kg
01 July 2020                        Neutrino2020 conference - 76Ge 0vbb decay                                   16
Final phase II data collection summary
                                      GERDA Phase II runs        Exposure             Physics data     Calibration data        Special calibration data

                                                                                                                                                                          Exposure (kg×yr)
Exposure gain (kg×yr / d)

                            0.10                                                                                                                                    100

                            0.08                                                                                                                                    80

                            0.06                                                                                                                                    60

                            0.04                                                                                                                                    40

                                                                                                                                                      GERDA 20-06
                            0.02                                                                                                                                    20

                            0.00                                                                                                                                    0
                             2016-01        2016-07         2016-12         2017-07        2017-12      2018-07           2018-12       2019-07
                                                                                                                                     Date (year-month)

           • data collection split in pre/post upgrade periods
                                   o pre-upgrade: data released at Neutrino2018 [Science 365, 6460 (2019)]
                                   o cumulated exposure 58.9 kg e yr
                                                                                                                                                   Coax
                                                                                                                                         BEGe
                                                                                                                                                   28.6
                                                                                                                                         31.5

           • upgrade: new LAr veto system + new IC detector string TAUP2019

       01 July 2020                                                   Neutrino2020 conference - 76Ge 0vbb decay                                                                 17
Final phase II data collection summary
                                      GERDA Phase II runs        Exposure             Physics data     Calibration data        Special calibration data

                                                                                                                                                                          Exposure (kg×yr)
Exposure gain (kg×yr / d)

                            0.10                                                                                                                                    100

                            0.08                                                                                                                                    80

                            0.06                                                                                                                                    60

                            0.04                                                                                                                                    40

                                                                                                                                                      GERDA 20-06
                            0.02                                                                                                                                    20

                            0.00                                                                                                                                    0
                             2016-01        2016-07         2016-12         2017-07        2017-12      2018-07           2018-12       2019-07
                                                                                                                                     Date (year-month)

           • data collection split in pre/post upgrade periods
                                   o pre-upgrade: data released at Neutrino2018 [Science 365, 6460 (2019)]
                                   o cumulated exposure 58.9 kg e yr

           • upgrade: new LAr veto system + new IC detector string TAUP2019
                                                                                                                                         IC
                                                                                                                                         8.5

           • this talk:                                                                                                                          Coax
                                                                                                                                                 41.8
                                   o final exposure: MN hi e Oj (original design: 100 kg e yr)                                  BEGe
                                                                                                                                    53.3
                                   o full data collection analysed
       01 July 2020                                                   Neutrino2020 conference - 76Ge 0vbb decay                                                                 18
76Ge              detector calibration
• weekly calibrations with 228Th sources

• every 20 s test pulse injection for gain
  stability measurement

                                                                          FWHM (keV)
                                                                                                4                                                                                         GERDA 18-06

                                                                                                                                                                              Qb b
                            FWHM resolution @ PHH (keV)                                    3.5
                                                                                                                                                                                     QØØ
      period             BEGe*             Coax**               IC                              3

  pre-upgrade         =. k ± N. <
Phase II physics data modeling before cuts
counts / 5 keV

                  104                                                                                Enriched detectors - 60.2 kg×yr          single-detector events
                                                                           Qbb ± 25 keV

                                                                                                                                                                         GERDA 19-07
                                       40       42
                                            K        K
                      3
                  10

                              2nbb                       214
                  102                                          Bi                         208
                                                                                                Tl                                                            210
                                                                             214
                                                                                   Bi                                                                               Po

                   10

                      1

                 10-1

                 10-2                                                                                                                  [JHEP 2020, 139 (2020)]
counts / 5 keV

                 103
                                                                                                                                                 coincidence events
                 102
                  10
                      1
                   -1
                 10
                 10-2
                               1000                                 2000                                 3000                          4000                   5000
                                                                                                                                                               energy [keV]

                          Published data collection: from Dec. 2015 to April 2018
                          Blinding strategy: Keep events falling in mnn ± 25 keV blinded
                          Data quality cuts + muon veto applied
                          Energy range above 39Ar spectrum (mn = 565 keV)

01 July 2020                                                          Neutrino2020 conference - 76Ge 0vbb decay                                                          20
103
cou

                                                                                                                                                                          GERD
                                                                                      40                                         60                 210
                                                                        2nbb                          42

   Phase II physics data modeling before cuts
                                                                                           K               K                          Co                  Po

                  102

                   10
counts / 5 keV

                  104                                               Enriched detectors - 60.2 kg×yr                             single-detector events
                    1                                Qbb ± 25 keV

                                                                                                                                                                          GERDA 19-07
                                                                                                      212          208           214                228
                                                                        Data          Model                 Bi +         Tl            Bi + 214Pb         Ac
                  103                                                   2nbb          40
                                                                                           K          42
                                                                                                           K                     60
                                                                                                                                      Co            210
                                                                                                                                                          Po
                  10-1

                   102
                  10-2
counts / 5 keV

                   10
                  103

                  102
                     1
                   10

                  10-11
                 10-1                                                                                                     [JHEP 2020, 139 (2020)]
                 10--22
                 10
counts / 5 keV

                               1000           2000                      3000                                             4000                                  5000
                  103                                                                                                                                           energy [keV]
                  102
                 MaGe
                   10 (Geant4) modelling
                                                                                                       K. Von Sturm poster
                 of GERDA
                    1
                                                                                                           Modeling of
                 10-1                                                                                  GERDA Phase II data
                 10-2
                               1000           2000                      3000                                             4000                                  5000
                                                                                Fine modelling of all individual parts:                                         energy [keV]

                                                                                Priors:   Constraints from screening
                                                                                          measurements
                                                                                Weakness: Fairly high spatial degeneracy
                                                                                          of some components (K, 214Bi)
                 Main outcome: no full energy peak or other structures close to mnn
01 July 2020                                    Neutrino2020 conference - 76Ge 0vbb decay                                                                                21
Phase II pulse shape discrimination
Analysis of the charge collection time profile informs about event type (bulk single/multi-site, surface events)
       BEGe and IC detectors: p/q                                                                                                         Coaxial detectors: ANN + risetime
                                                                                     0#!! decay signal efficiency:
                                                                                     • ~ÇÉ:;
                                                                                        aÄÅ = ([[. > ± )%

                                                                                     • ~ÖÜáà
                                                                                        aÄÅ = (?[. k ±
Phase II liquid argon veto performances
                                                                                                                                                     P. Krause poster
      Counts / 5 keV

                       5000   All detectors - 103.7 kg×yr

                                                                                                                                  GERDA 20-06
                                                       Prior liquid argon (LAr) veto                                                             The LAr instrumentation
                                                       After LAr veto                                                                           of GERDA and LEGEND-200
                                                       Monte Carlo 2n bb - T          from [EPJC 75 (2015) 416]
                       4000                                                     1/2
                               Counts / 1 keV

                                                                                      42
                                                                                        K
                                                                        40
                                                2000                      K
                                                                                           -
                       3000                                                            b
                                                                         EC
                                                1000
                                                                  40                           42
                                                                   Ar                           Ca
                                                  0        1460         1480     1500               1520     1540
                       2000
                                                                                                     Energy (keV)

                       1000

                              600                          800                1000                  1200            1400        1600
                                                                                                                       Energy (keV)
  • Stable operations over 4 years of data taking
  • 0#!! decay signal efficiency: ~åVj = (k>. k ± N. M)%
  • Crucial role in background suppression after PSD: ÷ ? in the ROI

01 July 2020                                                                          Neutrino2020 conference - 76Ge 0vbb decay                                            23
Phase II physics spectra after all analysis cuts

        •      [600 - 1900] keV – Almost pure ?[JJ decays sample
        •      [1450 - 1530] keV – Strong suppression of 40K and 42K gamma lines (LAr veto + MSE)
        •      [1900 - 2620] keV – Strong suppression of 214Bi and 228Th gamma lines + Compton
        •      > 3500        keV – Suppression of almost all a events (p+ contact)

        • Extremely powerful complementarity between LAr veto and PSD cuts!
01 July 2020                                  Neutrino2020 conference - 76Ge 0vbb decay             24
Zoom around the region of interest
    Dec. 2019

    Dec. 2015

•    Bkg index (BI) analysis window: [1930-2190] keV with the exclusion of 208Tl SEP and 214Bi FEP lines and mnn ± 25 keV
•    Prior to analysis cuts, BI = 143ëí
                                     %ê × 10
                                             %G cts⁄(keV e kg e yr)
                                                                                   ÷
Phase II energy spectrum after unblinding!

 Dec. 2019

 Dec. 2015

• Two new counts entering the mnn ± 25 keV blinding window since the last data release

• But still no count within PHH ± =ö …

01 July 2020                   Neutrino2020 conference - 76Ge 0vbb decay                 26
Statistical analysis and interpretation

            Frequentist analysis*:                                            Bayesian analysis with uniform prior*:
      • Median sensitivity for limit setting:                                 • Median sensitivity for limit setting:
         O. ] × OP?A Qj (kP% Ö. å. )                                                1.4 × 10,F yr (90% C. I. )
                  • Best fit → no signal                                          -.
                                                                               • )*/, > 1.4 × 10,F yr 90% C. I.
                • 90% C. L. lower limit:
                 ZP[
                  O/? > O. ] × OP
                                 ?A
                                    Qj                                                              L. Shtembari poster
                                                                                              Statistical methods for the new
*Statistical treatment found in [Nature 544, 47–52 (2017)]                                         data release of GERDA
+ includes 23.5 kgeyr phase I exposure
01 July 2020                                      Neutrino2020 conference - 76Ge 0vbb decay                                     27
Moving forward

                                                                    76
                                                                        Ge (88% enr.)
                                          1030

                                                                                                                            long-term
        LEGEND                            1029
                                                                                                                            M ton
         1000                                                                                                               XNY
                                                                                                                             M/= > MN
                                                                                                                                      =[ yr
                                          1028
                     T1/2 3s DS [years]

          LEGEND                                                                                                            mid-term
                                            27
            200                           10
                                                                                                                            =NN kg
                                                                                                                            XNY
                                                                                                                             M/= > MN
                                                                                                                                      => yr

                                          1026                                                   IO mmin
                                                                                                     bb
                                                                                                         range
           GERDA                                                                                 Background free
          MAJORANA                                                                               0.1 counts/FWHM-t-y
                                                                                                                            running/ended
                                          1025
                                                                                                 1.0 count/FWHM-t-y          MN
                                                                                                                                      =? yr

                                          1024 -3
                                                    10-2        10-1
                                                                                                                        3
                                            10                                  1           10         102             10
                                                                       Exposure [ton-years]

01 July 2020                                        Neutrino2020 conference - 76Ge 0vbb decay                                                 28
LEGEND: A worldwide joint effort
 LEGEND Collaboration meeting, Seattle, Washington, US December 2019
                                                                                                    LEGEND mission:
                                                                                              “The collaboration aims to
                                                                                                develop a phased, 76Ge
                                                                                               based double-beta decay
                                                                                              experimental program with
                                                                                                discovery potential at a
                                                                                              half-life beyond 1028 years,
                                                                                              using existing resources as
                                                                                                appropriate to expedite
                                                                                                     physics results.”
    Large Enriched Germanium Experiment for Neutrinoless JJ Decay

Univ. New Mexico                  University of South Carolina    University Tennessee                          Oak Ridge National Laboratory
L'Aquila University and INFN      Tennessee Tech University       Lancaster University                          Padova University
Lab. Naz. Gran Sasso              Jagiellonian University         University Liverpool                          Padova INFN
University Texas, Austin          University of Dortmund          University College London                     Czech Technical University Prague
Tsinghua University               Technical University Dresden    Los Alamos National Lab.                      North Carolina State University
Lawrence Berkeley Natl. Lab.      Joint Inst. Nucl. Res.          INFN Milano Bicocca                           South Dakota School Mines Tech.
University California, Berkeley   Duke University                 Milano University and Milano INFN             University Washington
Leibniz Inst. Crystal Growth      Triangle Univ. Nuclear. Lab.    Institute Nuclear Research Russ. Acad. Sci.   Academia Sinica
Comenius University               Joint Research Centre, Geel     National Research Center Kurchatov Inst.      University Tübingen
University of North Carolina      Max Planck Institute for        Lab. Exper. Nucl. Phy. MEPhI                  University South Dakota
University of Warwick             Nuclear Physics, Heidelberg     Max Planck Institute for Physics, Munich      University of Zurich
Sichuan University                Queens University               Technical University Munich                   Roma Tre University and INFN
01 July 2020                                       Neutrino2020 conference - 76Ge 0vbb decay                                                        29
LEGEND-200 ongoing LNGS program
     String preparation at LNGS                   First calibration spectra in March 2020                l   Ongoing since Feb 2020
     using GERDA infrastructure
                                                                                                         l   GERDA detectors
                                                                                                             + 4 L200 ICPC
                                                                                                             + 5 MJD PPC detectors
                                                                                                             operating in liquid argon

                                                                                                         l   First tests of new DAQ,
                                                                                                             calibration system
                                                                                                             under real conditions

                                                                                                         l   First spectra taken using
                                                                                                             new head electronics

                                                                                                         l   Data taking still ongoing
                                                                                                             while LNGS activities
                                                                                                             are impacted by COVID

   LEGEND-200 background Goal
            Ge Internal                             U, Th Chains
    Detector Mounts

Front Ends & Mounts
                                                    Atmospheric Ar
                                                    Ge Cosmogenics            •   Background contributions near Qββ after all cuts
                Cables
                                                    Surface a
                                                    Cosmic Rays
                                                                                  (NB: design exposure = 1 t e yr)
      Nylon Shrouds                                 Total
       Optical Fibers                                                         •   Monte Carlo + data-driven projections of
                                                                                  Ge U/Th, 42K, α based on GERDA, MJD data
       Preamplifiers
                                                                 GERDA

       42
         K b-decays

                  68
                    Ge
                  60
                    Co                                                        •   All others: Monte Carlo + assay-based projections
            a-emitters

µ-induced (3400 mwe)                                                          •   Grey bands indicate uncertainties in assays and
ALL BACKGROUNDS

                       10
                          -8
                               10-7
                                       -6
                                      10
                                             -5
                                            10       10-4           10
                                                                         -3
                                                                                  background rejection
                                                   [counts/(keV kg y)]
 01 July 2020                                     Neutrino2020 conference - 76Ge 0vbb decay                                              30
LEGEND-1000: Toward a ton-scale experiment
                                            2018                2019                      2020                 2021                   2022                 2023

                                                   GERDA (100 kg yr)                                                                              Possible locations:
                                                   MAJORANA (75 kg yr)                                                                            • SNOLab (Canada)
                                                      LEGEND-200 Purchase Isotope                                                                 • CJPL (China)
                                                                             Fabricate Detectors
                                                                                                                                                  • SURF (USA)
                                                                         Develop/Install New Lock,
                                                                                                                                                  • LNGS (Italy)
                                                                          Experimental Apparatus
                                                                                                          Integration/Commissioning

                                                                                                                               LEGEND-200 Data Runs, Goal: 1 t yr (~5-7 years)
                                                                                                 Ton-Scale Down-Select Process

                                                                                                                          LEGEND-1000 Design/Build, ~6yrs, 2021-2027

                                                                                                                      Earliest, and optimistic, LEGEND-1000 Data Start 2025/6

  LEGEND-1000 background Goal
            Ge Internal                                        U, Th Chains
                                                               Underground Ar
                                                                                            Reductions for LEGEND-1000:
                                                                                            • U/Th: optimized array spacing, minimize opaque
    Detector Mounts
                                                               Ge Cosmogenics
Front-Ends & Mounts                                            Surface a
                Cables                                         Cosmic Rays                          materials, larger detectors, better light
                                                                                                    collection, cleaner materials
                                                               Total
       Optical Fibers

       Preamplifiers

                                                                                            •       42Ar:   strong suppression by using udg. sourced Ar
                                                                            GERDA

       42
         K b-decays

                  68
                    Ge

                  60
                    Co                                                                      •       μ-induced: improved shielding, SNOLab depth
            a-emitters
                                                                                                               assumed
µ-induced (6000 mwe)

ALL BACKGROUNDS

                          -8           -6              -5                            -3
                                                                                            •       Surface α's: assumes achieved UL for BEGes and
                               10-7                               10-4
                                                                                                                ICPCs in GERDA
                       10             10             10                         10
                                                               [counts/(keV kg y)]
 01 July 2020                                                Neutrino2020 conference - 76Ge 0vbb decay                                                                           31
Summary
• MAJORANA: doubled exposure (50 kg e yr) to be released this year
  most stringent limits on !! decay to 76Se excited states at this conference
• GERDA data taking completed in Dec. 2019 – 104 kg e yr collected
  no signal observed @ mnn – new lower limit on 76Ge 0#!! decay half-life:
                   XNY
                     M/= > M. [ × MN=?
                                       Oj @ 90% C. L.
                                                                                76
                                                                                    Ge (88% enr.)
                                                            1030
• LEGEND-200 already using
  GERDA infrastructure at LNGS
  o Test of prototype electronics and                       1029
    DAQ started in existing cryostat,
  o to be followed by                                       1028
    infrastructure upgrade.
                                       T1/2 3s DS [years]

  o Data-taking will begin in 2021
                                                            1027

• LEGEND-1000: ton-scale
  experiment achievable with                                1026                                    IO mmin
                                                                                                        bb
                                                                                                            range

  modest evolution of                                                                               Background free

  LEGEND-200 design
                                                                                                    0.1 counts/FWHM-t-y
                                                              25
                                                            10                                      1.0 count/FWHM-t-y
  o goal to reach the 10,ê yr                                                                       10 counts/FWHM-t-y
    discovery potential sensitivity
                                                            1024 -3
                                                                      10-2   10-1
                                                                                                                           3
                                                              10                   1           10         102             10
01 July 2020                     Neutrino2020 conference - 76Ge 0vbb decayExposure [ton-years]                            32
List of MAJORANA DEMONSTRATOR related posters

                                                                                Go to:
                                                                                https://nusoft.fnal.gov/nova/nu2020postersession/

                                                                                Search for: “Majorana Demonstrator”
                                                                                             in “All Sessions”

                                                                                You’ll find up to 3 posters!
      https://nusoft.fnal.gov/nova/nu2020postersession/pdf/posterPDF-254.pdf

      https://nusoft.fnal.gov/nova/nu2020postersession/pdf/posterPDF-257.pdf

      https://nusoft.fnal.gov/nova/nu2020postersession/pdf/posterPDF-586.pdf

01 July 2020                                                      Neutrino2020 conference - 76Ge 0vbb decay                         33
List of GERDA related posters

                                                                                 Go to:
                                                                                 https://nusoft.fnal.gov/nova/nu2020postersession/

                                                                                 Search for: “GERDA” & ”in Ge” in “All Sessions”

                                                                                 You’ll find up to 5 posters!
      https://nusoft.fnal.gov/nova/nu2020postersession/pdf/posterPDF-342.pdf

      https://nusoft.fnal.gov/nova/nu2020postersession/pdf/posterPDF-365pdf

      https://nusoft.fnal.gov/nova/nu2020postersession/pdf/posterPDF-464.pdf

      https://nusoft.fnal.gov/nova/nu2020postersession/pdf/posterPDF-506.pdf

      https://nusoft.fnal.gov/nova/nu2020postersession/pdf/posterPDF-329.pdf
01 July 2020                                                       Neutrino2020 conference - 76Ge 0vbb decay                         34
List of LEGEND related posters

                                                                                 Go to:
                                                                                 https://nusoft.fnal.gov/nova/nu2020postersession/

                                                                                 Search for: “LEGEND” in “All Sessions”

                                                                                 You’ll find up to 8 posters!
        https://nusoft.fnal.gov/nova/nu2020postersession/pdf/posterPDF-80.pdf

        https://nusoft.fnal.gov/nova/nu2020postersession/pdf/posterPDF-113.pdf

                                                                                          https://nusoft.fnal.gov/nova/nu2020postersession/pdf/posterPDF-365.pdf

        https://nusoft.fnal.gov/nova/nu2020postersession/pdf/posterPDF-284.pdf

                                                                                          https://nusoft.fnal.gov/nova/nu2020postersession/pdf/posterPDF-392.pdf

        https://nusoft.fnal.gov/nova/nu2020postersession/pdf/posterPDF-311.pdf

                                                                                          https://nusoft.fnal.gov/nova/nu2020postersession/pdf/posterPDF-483.pdf

01 July https://nusoft.fnal.gov/nova/nu2020postersession/pdf/posterPDF-341.pdf
        2020                                                         Neutrino2020 conference - 76Ge 0vbb decay                                                     35
The end
Upper limit on ünn within 3# flavor model
                                                                         =
                                              NY =
                                                                 †HH
                    M/XNY     ñ NY
                       M/= = £p ß  ®
                                                                   †=©
                    • Lower 90% C. L. limit:         XNY
                                                      M/= > M. [ × MN
                                                                     =?
                                                                        Oj
                    • Converted into upper limit on: †HH < [N − M[= ¢;S
                    • Other inputs:
                        o £p = M. =>
                        o 76Ge NME ∈ [=. ?? − ?. Nñ] min NME from Coraggio et al. 2020
                                                                                                   max NME from Song et al. 2017

                                                                                                                                     m b b (eV)
                                                   m b b (eV)
m b b (eV)

                                                                                                                                                                                                       GERDA 20-06
                                                                                                                                                             normal ordering
                1                                                 1                                                                               1
                                                                                                                                                             inverted ordering

                          GERDA 2020
             10-1                                         10-1                                                                               10-1

                                                                                                                                                                                  b decay kinematics
                                                                                                            Cosmology (extd.)
                                                                                Cosmology (min.)

             10-2                                        10-2                                                                               10-2

             10-3                                        10-3                                                                               10-3

                          -3
                     10         10-2   10-1          1                   10-1                                                   1                     10-2            10-1       1
                                              m light (eV)                                                                          S (eV)                                        m b (eV)

01 July 2020                                                    Neutrino2020 conference - 76Ge 0vbb decay                                                                                                 37
76Ge                                      0#!! decay search history

                                                                    0⌫ lower limit
                                      103                         T1/2
                                                                                              Heidelberg
                                                                                                                               G ERDA
                                                                  background index                                                             1026
                                                                                               Moscow
background index (cts/(keV·kg·yr))

                                      102                                             ITEP/                            KKDC
                                                                                       IePY                            Claim                   1025
                                                                                                                                M AJORANA

                                                                                                                                                        0⌫ lower limit (yr)
                                      101                         UCSB/LBL
                                                                                                        IGEX
                                                                                                                                               1024
                                      100

                                                                                     St. Gotthard                                              1023
                                     10   1

                                                                                                                                                      T1/2
                                                         Milano

                                          2                                                                                                    1022
                                     10

                                     10   3                                                                                                    1021

                                     10   4                                                                                                    1020
                                          1965    1970   1975       1981      1986      1992        1997     2003      2008     2014    2019

   01 July 2020                                                            Neutrino2020 conference - 76Ge 0vbb decay                                                    38
Underground laboratories worldwide
                                                                                  see J. Heise talk

                            GERDA
                            LEGEND-200
                                      MAJORANA

                            [arXiv:1801.00587]

• Underground = passive background suppression for « free »
• Isotopic activation suppression (neutron capture – e.g. CDGe + ¨ → CC|Ge → CCAs + 2.7 MeV)
• Large experimental infrastructure required (shielding, cryostat, instrumentation)
• Size/depth/access compromise taken into account by the collaborations
01 July 2020                      Neutrino2020 conference - 76Ge 0vbb decay                       39
Phase II: From concept to design
                plastic scintillator panels                                       LAr veto                   low-mass, low-
                                                                              instrumentation              activity electronics
                          muon veto

      clean room

                                                                                        wavelength
                                                                                    shifting fibers with
                                                                                      SiPM read-out

                                                                                                                Ge detector
                                                                                                                   array
                  64 m3 LAr
                   cryostat
               coolant, shielding

                                                                                                                   low mass
                                                                                                                detector holder
            590 m3
       ultra-pure water
                                                                               BEGe detector

01 July 2020                                  Neutrino2020 conference - 76Ge 0vbb decay                                           40
Phase II physics data modeling before cuts
counts / 5 keV

                           104                                                                          Enriched detectors - 60.2 kg×yr                                     single detector events
                                                                           Qbb ± 25 keV

                                                                                                                                                                                                                             GERDA 19-07
                                                                                                                                                  212          208           214                       228
                                                                                                            Data                         Model          Bi +         Tl            Bi + 214Pb                Ac
                                   3
                           10                                                                               2nbb                         40
                                                                                                                                              K   42
                                                                                                                                                       K                     60
                                                                                                                                                                                  Co                   210
                                                                                                                                                                                                             Po

                           102

                                  10

                                   1

                        10-1

                       10-2                                                                                                                                           [JHEP 2020, 139 (2020)]
counts / 5 keV

                         103
                         102
                                  10                                                                                                10
                 counts / 2 keV

                                                                                                                   counts / 2 keV
                                                                                          GERDA 19-09

                                                                                                                                                                                                                                 GERDA 19-09
                                                              M1-enrBEGe - 32.1 kg yr                                                                                                   M1-enrCoax - 28.1 kg yr
                             10
                                  1
                                  -1
                      10 1                                                                                                           1
                    10-2
                                              1000                  2000                                    3000                                                     4000                                         5000
                                                                                                                                                                                                                   energy [keV]
                       10-1                                                                                              10-1

                     10-2                                                                                              10-2

                                       1950     2000   2050      2100          2150                                                       1950         2000                 2050                2100              2150
                                                                               energy [keV]                                                                                                                       energy [keV]
                 Main outcome: no full energy peak or other structures close to mnn
01 July 2020                                                            Neutrino2020 conference - 76Ge 0vbb decay                                                                                                           41
GERDA overall exposure summary

01 July 2020   Neutrino2020 conference - 76Ge 0vbb decay   42
Calibration stability
                                   • small contact detectors:                                                                                                                  May 2018 upgrade
Shift at 2.6 MeV Peak (keV)

                                                                                                              Shift at 2.6 MeV Peak (keV)
                                                                                                GERDA 20-06

                                                                                                                                                                                                              GERDA 20-06
                                        BEGe detectors                                                                                                IC detectors
                               2                                                                                                             2

                               1                                                                                                             1

                               0                                                                                                             0

                              -1                                                                                                            -1

                              -2                                                                                                            -2

                              2016-01 2016-07 2016-12 2017-07 2017-12 2018-07 2018-12 2019-07                                               2016-01 2016-07 2016-12 2017-07 2017-12 2018-07 2018-12 2019-07
                                                                                 Date (year-month)                                                                                             Date (year-month)

                                   • coaxial detectors:
Shift at 2.6 MeV Peak (keV)

                                                                                                GERDA 20-06
                                        Coaxial detectors
                               2
                                                                                                                                             Check for the 2.6 MeV gamma line
                               1
                                                                                                                                             shift from 228Th calibration source in
                               0
                                                                                                                                             each consecutive valid period of time
                              -1

                              -2

                              2016-01 2016-07 2016-12 2017-07 2017-12 2018-07 2018-12 2019-07
                                                                                 Date (year-month)

01 July 2020                                                                Neutrino2020 conference - 76Ge 0vbb decay                                                                                        43
Liquid argon veto stability
         • NYHH decay signal acceptance:
                  Acceptance (%)                                                                                                         May 2018 upgrade
                                                                                                                     GERDA 20-06

                                             98.5

                                             98.0

                                             97.5

                                             97.0

                                              2016-01   2016-07   2016-12   2017-07   2017-12   2018-07    2018-12    2019-07
                                                                                                                     Date (year-month)
PSD efficiencies stability
                             • small contact detectors:                                                                                                                                                                      May 2018 upgrade
Survival fraction

                                                                                                                                              Survival fraction
                    1.2                                                                                                                                           1.2
                            BEGe detectors - PSD cut stability                                                                                                            IC detectors - PSD cut stability

                                                                                                                                GERDA 20-06

                                                                                                                                                                                                                                                                              GERDA 20-06
                                    208                                                                                                                                           208
                                          Tl DEP 1593 keV           Compton Q     ± 35 keV         212
                                                                                                         Bi FEP 1621 keV                                                                Tl DEP 1593 keV          Compton Q      ± 35 keV         212
                                                                                                                                                                                                                                                       Bi FEP 1621 keV
                                                                             bb                                                                                                                                            bb
                      1                                                                                                                                             1

                    0.8                                                                                                                                           0.8

                    0.6                                                                                                                                           0.6

                    0.4                                                                                                                                           0.4

                    0.2                                                                                                                                           0.2

                          2016-01     2016-07       2016-12   2017-07    2017-12      2018-07   2018-12       2019-07      2020-01                                      2016-01     2016-07       2016-12    2017-07   2017-12      2018-07   2018-12       2019-07      2020-01
                                                                                                                   Date (year-month)                                                                                                                             Date (year-month)

                             • coaxial detectors:
Survival fraction

                    1.2
                            Coaxial detectors - PSD cut stability

                                                                                                                                GERDA 20-06
                                    208
                                          Tl DEP 1593 keV           Compton Q     ± 35 keV         212
                                                                                                         Bi FEP 1621 keV
                                                                             bb
                      1

                    0.8
                                                                                                                                                                                        PSD time stability checked
                                                                                                                                                                                        by looking at gamma lines
                                                                                                                                                                                        survival fraction from
                    0.6

                    0.4
                                                                                                                                                                                        individual calibration runs
                    0.2

                          2016-01     2016-07       2016-12   2017-07    2017-12      2018-07   2018-12       2019-07      2020-01
                                                                                                                   Date (year-month)

    01 July 2020                                                                                Neutrino2020 conference - 76Ge 0vbb decay                                                                                                                                        45
Time evolution of Alpha background
 • Coax detectors _ background (energy > 3500 keV) before cuts:                                                                                                               May 2018 upgrade
       corr. rate (cts/day/det)

                                                                                                                                                              GERDA 2020-06
                                                          enrCoax - PhaseII                                     enrCoax - PhaseII+
                                                                           -ln(2) t                                                -ln(2) t
                                    1                     f(t) = C + N exp                                      f(t) = C + N exp
                                                                             T1/2                                                    T1/2
                                                          C = (131 ± 11)E-3 cts/day/det                         C = (95 ± 17)E-3 cts/day/det
                                                          N = (1033 ± 52)E-3 cts/day/det                        N = (362 ± 47)E-3 cts/day/det
                                                          T1/2 = (138.4 ± 0.2) days                             T1/2 = (138.4 ± 0.2) days

                                  0.5

                                   0
                                        Jul 16   Dec 16    Jul 17                 Dec 17               Jul 18     Dec 18                      Jul 19
                                                                                                                                                date (month year)

 • BEGe detectors _ background (energy > 3500 keV) before cuts:
       corr. rate (cts/day/det)

                                                                                                                                                              GERDA 2020-06
                                                                     enrBEGe - PhaseII                                     enrBEGe - PhaseII+

                                                                                      -ln(2) t                                                 -ln(2) t
                                                                     f(t) = C + N exp                                      f(t) = C + N exp
                                                                                        T 1/2                                                    T 1/2
                                  0.1                                C = (39.8 ± 2.2)E-3 cts/day/det                       C = (36.7 ± 3.6)E-3 cts/day/det
                                                                     N = (53.3 ± 7.5)E-3 cts/day/det                       N = (23.3 ± 8.3)E-3 cts/day/det
                                                                     T 1/2 = (138.4 ± 0.2) days                            T 1/2 = (138.4 ± 0.2) days

                   0.05

                                   0
                                        Jul 16   Dec 16    Jul 17                 Dec 17               Jul 18     Dec 18                      Jul 19
                                                                                                                                                date (month year)

Main outcome: No critical recontamination of BEGe small-contact detector during the upgrade
              Detector handling procedure OK for LEGEND-200
01 July 2020                                                     Neutrino2020 conference - 76Ge 0vbb decay                                                                                       46
Pulse Shape Discrimination #1
                              BEGe detector:                       Ø (511 keV)                ] (208Tl DEP)

                                               Ø MSE                     SSE
                     rss≠
                     rÆs≠                                                                       Ø (511 keV)
                                ]                            _
                                              H
                                                • MSE cut: Low A/E cut set to
                                                  accept 90% of 208Tl DEP from cal.
                                                • Alpha cut: High A/E cut set to
                                                  +3∞ of SSE A/E band
                                                  No high energy alpha (E>3.5 MeV) survive

       SSE                                      • ~ÇÉ:;
                                 Alpha             aÄÅ = ([[. > ± )%

               MSE                                                               PSD uncertainties are systematics dominated

                                                                          T. Comellato poster
                                                                    Modelling the collective motion
                                                                    of charge carrier in Ge detectors
01 July 2020           Neutrino2020 conference - 76Ge 0vbb decay                                                           47
Pulse Shape Discrimination #2

               MSE
                                                 •   MSE cut: Artificial Neural Network
                                                     fed with SSE and MSE proxies from cal.
                                                     (208Tl DEP and 212Bi FEP)
                                                          cut set @ 90% acc. of 208Tl DEP events
                                                          ±≤≥≥ = (82.3 ± 3.1)%

                                                 •   Alpha cut: Charge collection risetime
                                                     [10%-90%]. Cut optimized from =YHH
                                                     and _ samples:
                                                        cut set @ max[±,.nn e 1 − ±¥ ]
                                                        ±µ∂ = (85.5 ± 1.0)%
                             Alpha
                                                 •   ~ÖÜáà
                                                      aÄÅ = (?[. k ±
The Best of MAJORANA & GERDA

   MAJORANA                                                                    GERDA
   • Radiopurity of nearby parts                                               • LAr veto
     (FETs, cables, Cu mounts, etc.)     Both                                  • Low-A shield, no Pb
   • Low noise electronics                • Clean fabrication
                                            techniques
     improves PSD                         • Control of surface                 GERDA achieved the lowest
   • Low energy threshold (helps            exposure                           background index:
     reject cosmogenic                    • Development of large               5 × 10%G cts⁄(keV e kg e yr)
     background)                            point-contact detectors
                                          • Lowest background and              LEGEND-200 needs only x3-5
                                            best resolution 0nbb               better.
 MAJORANA achieved best energy              experiments
 resolution: 2.5 keV FWHM at Qbb
01 July 2020                       Neutrino2020 conference - 76Ge 0vbb decay                                  49
Ge Detectors for LEGEND-200

       GERDA BEGes and MAJORANA PPCs                                                        BEGe

          ü Excellent energy resolution
          ü Superb pulse-shape sensitivity to reject multi-site
            and surface background events
                                                                                             PPC
          • But relatively small:  = 0.66 and 0.85 kg,
            respectively

       New Inverted-Coaxial Point Contact detectors
          ü First design proposed in 2011
                    [R. Cooper et al., NIM A665, 25 (2011)]

          ü Large active mass up to 3 kg
          ü Excellent resolution and pulse shape discrimination                           ICPC
            performance [A. Domula et al., NIM A891, 106 (2018)]
          ü Lower surface to volume ratio
          ü Reduced background due to lower number of
            channels per mass of 76Ge
          ü Production started early 2019
            About 60 detectors expected by fall 2021

01 July 2020                                  Neutrino2020 conference - 76Ge 0vbb decay            50
PEN — self-vetoing structural material
•   PEN — Poly(ethylene 2,6-naphthalate)
      - Scintillates, providing veto to potential backgrounds
      - Light yield ~1/3 of conventional plastic scintillators                                BEGe
      - Particle identification using pulse shape discrimination (PSD)
        possible
      - Functions as a wavelength shifter of LAr scintillation photons
        (128 nm)
                                                                                               PPC
      - Transparent in the visible range
      - Mechanically stronger than silicon, stronger than Cu at
        cryogenic temps.

•   Production of LEGEND-200 low-background detector
    holder plates
      - Possible replacement of Si detector holder plates
      - Plates produced via CNC machining using clean procedures
                                                                                            ICPC
      - PEN holders deployed in LEGEND “post GERDA test” at LNGS

•   R&D Activities
      - Enhanced cleanliness,
      - Dedicated test stands and simulations to further study optical
        properties:
      - WLS, Light yield, attenuation, surface effects
      - Injection molded components (encapsulation of objects)                                       Design

01 July 2020                                    Neutrino2020 conference - 76Ge 0vbb decay                     51
You can also read