1. +

2. G & M Experimental Search for Neutrinoless Double Beta Decay of 76 Ge (GERDA-MAJORANA) Participants from Dubna: V.Brudanin, M.V. Chirchenko I.Chirikov-Zorin, V.Egorov, K.Gusev, S.Katulina, A.Klimenko, O.Kochetov, I.Nemchenok, N.Rukhadze, V.Sandukovsky, A.Smolnikov, Yu.Shitov, V.Timkin, S.Vasiliev, Ts.Vylov, E.Yakushev, J.Yurkowski.

3. Physics goals 0  :(A,Z)  (A,Z+2) + 2e - d d u u e-e- e-e- W-W- W-W- e e  L=2 Primary Objective:  Effective mass: Method: Operation of HP Ge-diodes enriched in 76 Ge under low-background conditions. Line search at Q ββ = 2039 keV m ee = |  i U ei ² m i | (decay generated by (V-A) cc-interaction via exchange of light Majorana neutrinos) Other Physics: WIMP DM search  Majorana nature

4. Double beta  (0 ) decay : experimental observable

5. >.. AA m. t N BDF. R N : Avogadro k C.L. = 1,6445 @ 90% C.L. A : atomic mass t : measurement duration (year) ln2. N k C.L. (years) Mass of isotope  (g) Background (year - 1. g - 1. keV - 1 )FWHM (keV) Detection efficiency Instrumental aspect:  : phase-space integral M : nuclear matrix element : neutrino effective mass m i : eigen state masses of U ei : mixing matrix elements = Theoretical aspect:  ( ) M 2 2 Q5Q5  1 = Half-life for  decay >.. AA m. t N exclu ln2. N k C.L. (years) Number of excluded events =2.3 (if BKG=0) If gaussian background: If background  0:

6. …Ongoing experiments NEMO-3 100 Mo (7)Track + Pl.Sc. France4×10 24 200–3002008 CUORICINO 130 Te (11) BolometersItaly7×10 24 2002007 …Realistic projects for the next 10 years Super_NEMO 82 Se (100)Track + Pl.Sc. (France)1×10 26 302011 CUORE 130 Te (200) BolometersItaly3×10 26 15–902010 EXO 136 Xe (200) TPCUSA2×10 26 390–1200>2005 project Isotope (kg) det.typeplaceT½ [yr] [meV]when Gerda-I 76 Ge (15) Ge-det.Italy3×10 25 300–9002006 Gerda-II 76 Ge (35) Ge-det.Italy2×10 26 90–2902009 Gerda-III 76 Ge (1000) Ge-det.?10 28 10 Majorana 76 Ge (500) Ge-det.?4×10 27 34–392015 Comparison of G&M with… …completed experiments Hd-M 76 Ge (11) Ge-det.Italy>1.5×10 25 <3002001 Hd-M (HKVK) 76 Ge (11) Ge-det.Italy1.2×10 25 4402004 IGEX 76 Ge (8) Ge-det.Spain>1.6×10 25 <3002002

7. H.V. Klapdor-Kleingrothaus, A. Dietz, O. Chkvorets, I.V. Krivosheina, NIM A522 (2004)

8. GERDA Germanium Detector Array for the search of neutrinoless  - decays of 76 Ge at LNGS The Majorana Zero- Neutrino Double-Beta Decay Experiment Majorana &

9. GERDA Germanium Detector Array for the search of neutrinoless  decays of 76 Ge at LNGS Presentation of the proposal P38/04 to the LNGS-SC,

10. Range of m ee derived from oscillation experiments  m ee = f(m 1,  m² sol,  m² atm,  12,  13,  -  ) | m ee | in eV Lightest neutrino (m 1 ) in eV F.Feruglio, A. Strumia, F. Vissani, NPB 659 H.V. Klapdor-Kleingrothaus, A. Dietz, O. Chkvorets, I.V. Krivosheina, NIM A522 (2004) Sensitivity of this project: Phase I: Phase II: Phase III:

11. Experimental concept Reduction of backgrounds key to sensitivity : –Lifetime limit w/o backgrounds: t 1/2  (MT) with backgrounds: t 1/2  (MT) 1/2 Operation of bare Ge diodes in high-purity LN 2 / LAr shield (Heusser, Ann, Rev. Nucl. Part. Sci. 45 (1995) 543); proposals based on this idea: GENIUS (H.V. Klapdor-Kleingrothaus et. al., hep-ph/9910205 (1999)); GEM (Y.G. Zdesenko et al., J. Phys. G27 (2001)) Baseline: LN 2 ; possible upgrade LAr:  =1.4 g/cm 3, active anti-coincidence with scintillation light from LAr  Goal: background free!

12. LNGS, November 2004

13. Detector suspension Purity requirement for support materials < 20  Bq/kg !

15. Baseline design Clean room lock Vacuum insulated copper vessel Water tank / buffer Liquid N/Ar Ge Array

16. Phases and physics reach: DBD Phase I: implementation of existing Ge-76 diodes (~15 kg) of HdM and IGEX in new experiment (“background free”) –operation in LN2 with background <10 -2 / keV kg y –>15 kg y (free of background): scrutinize claim (97.8% excl. or 5 sigma confirmation) –sensitivity: 3 · 10 25 y, 0.24-0.77 eV Phase II: enlarge to ~35-40 kg (background <10 -3 / keV kg y) –within 4 years: ~100 kg y –sensitivity: 2 · 10 26 y, 0.09-0.29 eV Phase III: (depending on physics results of Phase I+II and on the understanding of backgrounds) –world-wide collaboration (Majorana):  500 kg (close Gerda-Majorana cooperation established: common review & MC workshop at LNGS in parallel to SC meeting)

17. Background summary Phase I: external ~ 10 -3 / (keV kg y) internal < 10 -2 / (keV kg y) Phase II: (With segmentation) (No segmentation) Units: 10 -3 / (keV kg y)

18. Technical aspects of the experiment

19. Location in hall A  Modification of ramp design !!

20. Tyvek Alternative: Radiant mirror foil Final optimization after freezing of tank system design Muon Veto Plastic scintillator

21. Schedule & Phases Start of Construction

22. Cost estimates & status of funding Cap. Investment Phase I:6490 kEuro Phase II:3830 kEuro (~70% of funding secured)

23. Collaboration Structure CB Chair: A. Caldwell Spokesperson: S. Schoenert Co-spokespers.: C. Cattadori Tech. Coord.: K-T. Knoepfle GLIMOS: tbd RAE: tbd as worked out in collaboration internal MoU

24. Task groups T1: Modification and test of the existing Ge diodes (Schoenert) T2: Design and production of new Ge diodes (Caldwell) T3: Diode readout and signal processing (Cattadori) T4: Cryogenic vessel (Knoepfle) T5: Infrastructure on top of vessel (Abt) T6: Water vessel and muon veto water Cherenkov (Bettini) T7: Scintillator muon veto on top of vessel (Brudanin / Egorov) T8: Infrastructure & logistics for Gerda (Junker) T9: DAQ Electronics & software (Schwingenheuer) T10: Simulation and background studies (Pandola / Abt) (Preliminary task responsible)

25. Summary Collaboration formed: expertise Aggressive Schedule: start construction summer 2005; first physics 2007 ~70% of funding secured Manpower sufficient to get project going: ~30 FTE staff physicist + 9 FTE engineer Competitive with relevant physics results already in Phase I Need approval to keep schedule

26. INFN LNGS, Assergi, Italy A.Di Vacri, M. Junker, M. Laubenstein, C. Tomei, L. Pandola JINR Dubna, Russia V. Brudanin, V. Egorov, K. Gusev, S. Katulina, A. Klimenko, O. Kochetov, I. Nemchenok, V. Sandukovsky, A. Smolnikov, J. Yurkowski, S. Vasiliev, MPIK, Heidelberg, Germany C. Bauer, O. Chkvorets, W. Hampel, G. Heusser, W. Hofmann, J. Kiko, K.T. Knöpfle, P. Peiffer, S. Schönert, J. Schreiner, B. Schwingenheuer, H. Simgen, G. Zuzel Univ. Köln, Germany J. Eberth, D. Weisshaar Jagiellonian University, Krakow, Poland M.Wojcik Univ. di Milano Bicocca e INFN, Milano, Italy E. Bellotti, C. Cattadori INR, Moscow, Russia I. Barabanov, L. Bezrukov, A. Gangapshev, V. Gurentsov, V. Kusminov, E. Yanovich ITEP Physics, Moscow, Russia V.P. Bolotsky, E. Demidova, I.V. Kirpichnikov, A.A. Vasenko, V.N. Kornoukhov Kurchatov Institute, Moscow, Russia A.M. Bakalyarov, S.T. Belyaev, M.V. Chirchenko, G.Y. Grigoriev, L.V. Inzhechik, V.I. Lebedev, A.V. Tikhomirov, S.V. Zhukov MPP, München, Germany I. Abt, M. Altmann, C. B\"uttner. A. Caldwell, R. Kotthaus, X. Liu, H.-G. Moser, R.H. Richter Univ. di Padova e INFN, Padova, Italy A. Bettini, E. Farnea, C. Rossi Alvarez, C.A. Ur Univ. Tübingen, Germany M. Bauer, H. Clement, J. Jochum, S. Scholl, K. Rottler GERDA Collaboration 71 physicists listed; 30 full time equivalent staff + 5 PhD students 9.5 FET engineer/technician 1.8 + 1 6 + 2 6 + 1 0.3 1.3 4 3 4 1.6 2+1

29. Phase 1: 1 segmented Ge crystal (first one is under preparation) Phase 3: Majorana 210 Ge detectors, ~ 10 years of construction Ten 21-crystal modules Phase 2: 16 outer p-type Ge crystals (already in hand) 2 inner segmented detectors  Produce (through US manufacturers) test detectors (n-type, p-type)  Validate and Optimize the background rejection methods  Test the manufacturers ability to make segmented n-type detectors with enriched Ge, building in an underground facility  Test enrichment chemical processing by Russian and subsequent ability of US manufacturers to construct detectors from this material  Materials + Cryo-design + Geometry Tests Estimates from: Krasnoyarsk Ge production Commercial Ge detector segmentation Commercial waveform digitizers

30. In TEST In preparation

33. MAJORANA США-Россия Методы: Сегментация ( фактор 7.2 – симуляция ) улучшенный PSA ( фактор 3.8 ) антисовпадения детекторов ~ 4  10 27 лет (90% CL) ~ 0.045 эВ Ожидаемая чувствительность Статус: поддержка ожидается в 2007, результат ? Источник: 500 кг 76 Ge (120 кг первая стадия) Конфигурация: 10 сборок  21 детектора Экспозиция: 10 лет R&D: снижение фона с нынешних 0,2 отсчетов  год -1  кг -1  кэВ -1 до 0,001 отсчетов  год -1  кг -1  кэВ -1 :

35. Plastic Muon Veto (Possible JINR contribution)

36. Muons in copper

37. Light collection with fibers 2 m 0.5 m 2 cm 5 cm PMT: R7400 Inhomogenity of the light collection: less than 10% less than 10%

38. Hamamatsu PMT module H6780 PMT H6780 HV divider HV power supply (Amplifier)

39. 3 cm 3 cm 4 cm 4 cm 5 cm 5 cm 2 cm 2 cm

40. 4 m 16 m 2 20 m 2

41. Radon detector (Possible JINR contribution)

43. High sensitivity Radon detector Large clean vesselLarge clean vessel Electrostatic collection of the 222 Rn daughtersElectrostatic collection of the 222 Rn daughters Energy spectrum of α- particles measured with PIN-diodeEnergy spectrum of α- particles measured with PIN-diode 0.4 m  0.5 m 222 Rn 218 Po + Sensitivity Sensitivity  1 mBq/m 3  1 mBq/m 3

45. Used in NEMO-3

46. JINR contribution JINR contribution: Muon veto (plastic scint.) Radon detectors Handling Ge detectors (we have a special group which can do it) 4 kg of 76 Ge → SEGA (Majorana) Data analysis, simulation, etc. We’ll see…