Office of Nuclear Physics
MAJORANA
The MAJORANA DEMONSTRATOR A search for neutrinoless double-beta decay of germanium-76
Alexis Schubert on behalf of the MAJORANA Collaboration
Center for Experimental Nuclear Physics and Astrophysics The MAJORANA Collaboration (June 2011) Note: Red text indicates students
The MAJORANA Collaboration MAJORANA
Pacific Northwest National Laboratory, Richland, Washington Black Hills State University, Spearfish, SD Craig Aalseth, Estanislao Aguayo, Jim Fast, Eric Hoppe, Kara Keeter Todd Hossbach, Marty Keillor, Jeremy Kephart, Richard T. Kouzes, Harry Miley, John Orrell, Doug Reid Duke University, Durham, North Carolina , and TUNL Matthew Busch, James Esterline, Gary Swift, Werner Tornow Queen's University, Kingston, Ontario Art McDonald Institute for Theoretical and Experimental Physics, Moscow, Russia Alexander Barabash, Sergey Konovalov, South Dakota School of Mines and Technology, Rapid City, South Dakota Igor Vanushin, Vladimir Yumatov Cabot-Ann Christofferson, Mark Horton, Stanley Howard
Joint Institute for Nuclear Research, Dubna, Russia University of Alberta, Edmonton, Alberta Viktor Brudanin, Slava Egorov, K. Gusey, Aksel Hallin Oleg Kochetov, M. Shirchenko, V. Timkin, E. Yakushev University of Chicago, Chicago, Illinois Lawrence Berkeley National Laboratory, Berkeley, California and Juan Collar, Nicole Fields the University of California - Berkeley Mark Amman, Marc Bergevin, Yuen-Dat Chan, Jason Detwiler, University of North Carolina, Chapel Hill, North Carolina and TUNL James Loach, Paul Luke, Ryan Martin, Alan Poon, Gersende Prior, Padraic Finnerty, Florian Fraenkle, Graham Giovanetti, Matthew Green, Kai Vetter, Harold Yaver Reyco Henning, Mark Howe, Sean MacMullin, David G. Phillips II, Jacqueline Strain, Kris Vorren, John F. Wilkerson Los Alamos National Laboratory, Los Alamos, New Mexico Melissa Boswell, Steven Elliott, Victor M. Gehman, University of South Carolina, Columbia, South Carolina Andrew Hime, Mary Kidd, Ben LaRoque, Keith Rielage, Larry Frank Avignone, Leila Mizouni Rodriguez, Michael Ronquest, Harry Salazar, David Steele University of South Dakota, Vermillion, South Dakota North Carolina State University, Raleigh, North Carolina and TUNL Vince Guiseppe, Tina Keller, Keenan Thomas, Dongming Mei, Dustin Combs, Lance Leviner, Albert Young Gopakumar Perumpilly, Chao Zhang
Oak Ridge National Laboratory, Oak Ridge, Tennessee University of Tennessee, Knoxville, Tennessee Fred Bertrand, Greg Capps, Ren Cooper, Kim Jeskie, Yuri Efremenko, Sergey Vasiliev David Radford, Robert Varner, Chang-Hong Yu University of Washington, Seattle, Washington Osaka University, Osaka, Japan Tom Burritt, Jonathan Diaz, Peter J. Doe, Greg Harper, Robert Johnson, Hiroyasu Ejiri, Ryuta Hazama, Masaharu Nomachi, Shima Tatsuji Andreas Knecht, Michael Marino, Mike Miller, David Peterson R. G. Hamish Robertson, Alexis Schubert, Tim Van Wechel, Brett Wolfe
The MAJORANA DEMONSTRATOR PANIC11 Neutrinoless double-beta decay (0νββ) MAJORANA
• Observation indicates: Neutrino is a Majorana particle • • Lepton number is not conserved summed electron energy • Measurement of rate could provide information about neutrino mass 2νββ
counts 0νββ
Q-value
The MAJORANA DEMONSTRATOR 3 PANIC11 Neutrino mass and 0νββ MAJORANA
Sensitivity of a tonne-scale 76Ge experiment
0νββ rate
(T1/2)-1 = G0ν M0ν 2 mββ2 Double-Beta Decay andNeutrino Neutrino mass hierarchy Mass
m3 m2
m1 Normal $mAtm%45 meV Hierarchy Inverted Hierarchy !e !" !# NME: Simkovic et al, Phys Ref C 79, 055501 (2009) m2 m3 $mSol%9 meV m1 iδ i α1 c12c13 s12c13 s13e− e 2 00 iδ iδ i α2 U = s12c23 c12s23s13e c12c23 s12s23s13e s23c13 0 e 2 0 − − iδ − iδ s12s23 c12c23s13e c12s23 s12c23s13e c23c13 0 0 1 − − − 2 mββ = Ueiξimi ! " ! ! ! i ! The MAJORANA D!EMONSTRATOR" ! 4 PANIC11 ! ! 0!&& is sensitive to! !m&&", !and therefore the absolute masses, mixings and CP phases The GERDA and MAJORANA Experiments MAJORANA
MAJORANA
Detector array: enriched Ge crystals Detector array: enriched Ge crystals in submerged in liquid argon vacuum cryostats
Shield: high-purity liquid argon, H20 Shield: lead, copper http://www.mpi-hd.mpg.de/gerda http://majorana.npl.washington.edu
Goal: select best techniques developed in GERDA and MAJORANA for a joint tonne-scale Ge experiment
The MAJORANA DEMONSTRATOR 5 PANIC11 The GERDA and MAJORANA Experiments MAJORANA
MAJORANA 14:30 4-163 Status and Perspective of the GERDA Neutrinoless Double Beta Decay Experiment Karl Tasso Knoepfle
Detector array: enriched Ge crystals Detector array: enriched Ge crystals in submerged in liquid argon vacuum cryostats
Shield: high-purity liquid argon, H20 Shield: lead, copper http://www.mpi-hd.mpg.de/gerda http://majorana.npl.washington.edu
Goal: select best techniques developed in GERDA and MAJORANA for a joint tonne-scale Ge experiment
The MAJORANA DEMONSTRATOR 5 PANIC11 The MAJORANA Experiment MAJORANA
• Search for neutrinoless double-beta decay using an array of germanium detectors enriched in 76Ge
• First phase of MAJORANA under construction: the DEMONSTRATOR, 40-kg R&D detector • Attempt to achieve a background rate 100x lower than previous Ge experiments
The MAJORANA DEMONSTRATOR 6 PANIC11 The MAJORANA Experiment MAJORANA
• Search for neutrinoless double-beta decay using an array of germanium detectors enriched in 76Ge
• First phase of MAJORANA under construction: the DEMONSTRATOR, 40-kg R&D detector • Attempt to achieve a background rate 100x lower than previous Ge experiments
Background goal for tonne-scale: 1 count per tonne-year in 4-keV region surrounding Q-value
The MAJORANA DEMONSTRATOR 6 PANIC11 The MAJORANA DEMONSTRATOR MAJORANA
• First phase of the MAJORANA experiment • 40-kg ultra-clean Ge detector array deployed in two cryostats at 4850ʼ level of Sanford Lab • 20 to 30 kg of crystals enriched to 86% 76Ge • Technical goal: demonstrate background levels that justify construction of tonne-scale experiment • Science goal: test recent claim of 0νββ observation - Phys. Lett. B 586 198 (2004)
the inside of The MAJORANA DEMONSTRATOR 7 a cryostat PANIC11 The MAJORANA DEMONSTRATOR MAJORANA
Ge detector detector string
cryostat
TheThe M DAJORANAEMONSTRATOR DEMONSTRATOR 8 PANIC11 The MAJORANA DEMONSTRATOR MAJORANA
Ge detector detector string
cryostat
TheThe M DAJORANAEMONSTRATOR DEMONSTRATOR 8 PANIC11 The MAJORANA DEMONSTRATOR MAJORANA
Ge detector detector string
cryostat
TheThe M DAJORANAEMONSTRATOR DEMONSTRATOR 8 PANIC11 The MAJORANA DEMONSTRATOR MAJORANA
Ge detector detector string
cryostat
TheThe M DAJORANAEMONSTRATOR DEMONSTRATOR 8 PANIC11 The MAJORANA DEMONSTRATOR MAJORANA
Ge detector detector string
cryostat
TheThe M DAJORANAEMONSTRATOR DEMONSTRATOR 8 PANIC11 The MAJORANA DEMONSTRATOR MAJORANA
Ge detector detector string
cryostat
TheThe M DAJORANAEMONSTRATOR DEMONSTRATOR 8 PANIC11 The MAJORANA DEMONSTRATOR MAJORANA
Passive and active shielding: polyethylene scintillator veto radon exclusion box lead commercial copper electro-formed copper
The MAJORANA DEMONSTRATOR 9 PANIC11 Germanium detectors MAJORANA • MAJORANA will use p-type point contact Ge detectors • Excellent energy resolution: 0.16% FWHM at 2039 keV Q-value • Can be enriched to 86% in 76Ge: source is detector • Pulse-shape analysis can distinguish multi-site backgrounds from single-site signal events • Low energy threshold allows opportunistic physics: dark matter search
energy spectrum with pulse-shape analysis model of electric field in PPC detectors 30 1
25 0.8 208 20 Tl all events 0.6 15 DEP single-site events Z (mm) 0.4 10
0.2 5
0 0 -30 -20 -10 0 10 20 30 Radius (mm)
The MAJORANA DEMONSTRATOR 10 PANIC11 Backgrounds MAJORANA
The MAJORANA DEMONSTRATOR 11 PANIC11 Backgrounds MAJORANA
Intrinsic radiation: U and Th decay chains, 2νββ
Cosmic rays: Expected backgrounds • Activation at surface creates unstable isotopes in Ge, copper • Muons, muon-induced neutrons can interact in detectors and apparatus
The MAJORANA DEMONSTRATOR 11 PANIC11 Backgrounds MAJORANA
Intrinsic radiation: U and Th decay chains, 2νββ
Cosmic rays: Expected backgrounds • Activation at surface creates unstable isotopes in Ge, copper • Muons, muon-induced neutrons can interact in detectors and apparatus
Background Passive and active shielding: copper, lead, polyethylene, scintillator reduction Ultra-clean materials: Ge, copper, parylene techniques Depth: experiment will be conducted deep underground
The MAJORANA DEMONSTRATOR 11 PANIC11 Backgrounds MAJORANA
Intrinsic radiation: U and Th decay chains, 2νββ
Cosmic rays: Expected backgrounds • Activation at surface creates unstable isotopes in Ge, copper • Muons, muon-induced neutrons can interact in detectors and apparatus
Background Passive and active shielding: copper, lead, polyethylene, scintillator reduction Ultra-clean materials: Ge, copper, parylene techniques Depth: experiment will be conducted deep underground
Analysis cuts: 0νββ should deposit energy in a small region of a single detector; other events can be flagged: Background mitigation • events that deposit energy in multiple detectors techniques • events that deposit energy in multiple locations in one detector • events that are time correlated with other events The MAJORANA DEMONSTRATOR 11 PANIC11 Recent progress MAJORANA
• DOE and NSF funding started in FY 2010 • November 2010: 19 of 36 natural Ge detectors delivered to Sanford Lab • April 2011: All 36 natural Ge detectors characterized and accepted by Los Alamos National Lab
• June 2011: Isoflex completed enrichment of 20 kg Ge; delivery by Sept. 2011 • August 2010: Production of electro-formed copper started in shallow site at Pacific Northwest National Lab
• July 2011: Ten electro-forming baths operational at Sanford 4850ʼ level • Preparation of lab in Davis Campus at Sanford 4850ʼ level is underway
The MAJORANA DEMONSTRATOR 12 PANIC11 Progress and Highlights
1.04 : Progress on assay R&D (U in Cu); Assays moving along. 1.05 : Electroforming UG at PNNL; Electroforming outfitting in TCR moving forward. 76 1.06 : 1st 20 kg of Ge ordered; isotopic makeupRecent looks progress: good; germanium detectors refinement facility constructed, some operations. MAJORANA
Facility Fractionalestablished Underground Isotope Composition for reduction storage facility 70Ge 0.00006(1)of GeO2 to in Cherokee metal, zone Caverns 72Ge 0.00011(1)refinement of Ge metal 73Ge 0.00033(3)
104 74Ge 0.086(5)
19 natural 103 76 Ge Ge0.914(5) detectors delivered to 102 Ongoing MC Sanford in background November 10 MJ Collaboration Meeting MJD – Status and Overview 6 simulation 10 May 2011 2010 counts / 5 keV campaign 1
10-1
-2 10 0 500 1000 1500 2000 2500 3000 Energy [keV] The MAJORANA DEMONSTRATOR 13 PANIC11 Recent progress: production of MAJORANA Dec. 2010 ultra-clean copper
electro-formingExterior view of TCRlaboratory at the 4850 level of atSUL Sanford 5/11/11 Cabot-Ann Christofferson, MJD Collaboration 3
electro-forming baths in the underground clean room at 4850ʼ machining of electro-formed level of Sanford Lab copper from PNNL The MAJORANA DEMONSTRATOR 14 PANIC11 Front End Electronics and Cables Front End FET • Requires materials very low in radioactive impurities Au/Cr • Trace proximity of traces provides ~1 traces pF Amorphous Ge Silica substrate resistor • Silica or sapphire substrate provides thermal control • Amorphous Ge resistor: deposit in H gives proper resistance at low temperatureRecent progress: electronics and cabling MAJORANA Front End Preamp
prototype front-end clean electronics Custom Parylene coated wiresparylene cable production Mounting the string 1 mm
V. E. Guiseppe NOW 2010 15 multiple- detector electronics parylene test string ribbon ~ 3 mm cable
The MAJORANA DEMONSTRATOR 15 PANIC11 Summary and Outlook MAJORANA
• Observation of neutrinoless double-beta decay would determine Majorana nature of the neutrino and could provide information about neutrino mass
• MAJORANA will search for 0νββ of 76Ge with an array of Ge detectors • Construction of the first phase of MAJORANA, the DEMONSTRATOR, is underway: • Beneficial occupancy of MJD lab by May 2012 • Prototype cryostat of natural Ge by late summer 2012 • Enriched material ready for detector fabrication by February 2012 • First module with enriched Ge in 2013
The MAJORANA DEMONSTRATOR 16 PANIC11 Thank you! MAJORANA
The MAJORANA DEMONSTRATORThe MAJORANA17 Collaboration PANIC11 Estimated KATRIN neutrino mass Sensitivity MAJORANA 1 disfavored2 by+ 00.0222νββ 2 + 0 Sin #12 = 0.32- 0.0197 Sin #13 = 0.039- 0.039
$m = 7.59e-05+ 2e-06 $m = 2e-03+ 1e-04 Klapdor-KleingrothausSolar - 2e-06 etAtm al. claimed- 1e-04 signal 10-1
Inverted disfavored by cosmology mass (eV)
! -2 ! 10 "
Normal 10-3 Effective 0 Effective
10-4 10-4 10-3 10-2 10-1 1 Lightest mass (eV)
The MAJORANA DEMONSTRATOR 18 PANIC11 Isotopic concentrations of enriched materialMAJORANA
Isotope Fractional Composition
70Ge 0.00006(1)
72Ge 0.00011(1)
73Ge 0.00033(3)
74Ge 0.086(5)
76Ge 0.914(5)
PNNL measurement of material from ECP The MAJORANA DEMONSTRATOR 19 PANIC11