1. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain The GERDA Experiment at Gran Sasso Grzegorz Zuzel Institute of Physics, Jagiellonian University, Cracow, Poland on behalf of the GERDA Collaboration

2. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain Overwiew Goals of GERDA Design of the experiment Present status - Background for nat Ge - Background for enr Ge - Liquid argon instrumentation: LArGe - GERDA phase II Conclusions and future plans

3. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain The Collaboration 95 physicists from 17 institutions from Germany, Italy, Russia, Poland,Belgium,Switzerland and China GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

4. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain Goals of GERDA GERDA (GERmanium Detector Array) has been designed to investigate neutrino-less double beta decay of 76 Ge - Ge mono-crystals are very pure - Ge detectors have excellent energy resolution - Detector = source - Enrichment required (7.4 %  86 %) Background level: 10 -2 – 10 -3 cts/(keV kg  y) Realization in phases: - Phase I: 17.8 kg (8 diodes) of enr Ge from HdM & IGEX experiments available (15.3 kg of 76 Ge) - Phase II: adding new detectors, 37.5 kg of enriched material in hand, p-type BEGe detectors (~20 kg) will be produced - Phase III: world-wide collaboration, O(500 kg) of 76 Ge GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

5. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain Bare high purity enr Ge detectors GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

6. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain Sensitivities GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II. ~ 0.1 eV KKDC phase I phase II

7. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain Sensitivities GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II. KK claim

8. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain t = 3/6 cm copper Ø 4.2 m h 8.9 m Active cooling Design of the experiment GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

9. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain Design of the experiment clean room lock water tank +  veto cryostat cryo-mu-lab control room water plant Rn monitor GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

10. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain Design of the experiment GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

11. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain Unloading of cryostat 6 Mar 08 GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

12. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain Construction of water tank Water tank: Ø 10 m h = 9.5 m V = 650 m 3 V H2O = 590 m 3 19 May 08 GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

13. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain Construction of clean room 27 Feb 09 GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

14. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain Muon veto in water tank 12 aug 09 GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

15. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain GERDA in Hall C GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

16. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain GERDA milestones 2005 – 2010: GERDA funded, designed and constructed in LNGS Hall A June 2010: Commissioning started. One string (3 nat Ge detectors, 7.6 kg) deployed for the first time. Checking the detector’s performance June 2010 – June 2011: Detailed investigation of background sources with nat Ge ( 42 Ar, 228 Th, cosmogenics) June 2011: Deployment of the first string of enr Ge (3 detectors, 6.7 kg) GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

17. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain Background for nat G: 42 Ar 2.1 cts/kg/day @ 1525 keV 92 d exposure (July – November 2010) GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

18. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain Background for nat G: 42 Ar GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

19. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain Background for nat G: 42 Ar  I @ 1524 keV < 0.094 (cts/kg*d) I @ Q  <1.7 10 -3 (cts/keV kg  y) 42 Ar production: 40 Ar( ,2p) 42 Ar reaction in atmosphere and fall-out from atmospheric nuclear explosions 42 Ar concentration: measured < 50  Bq/l  < 0.094 cts/(kg  d) in GERDA geometry, for an homogeneous distribution around the detectors. Background @ Q bb From 42 K  -s when decays happen in the detector borehole or @ Li layer Hard bremssthralung of > 2 MeV  -s in LAr GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

20. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain Background for nat G: other sources GERDA Rate @ 2614 keV = 4.83 cts/(kg  y) HdM Rate @ 2614 keV = 26 cts/(kg  y) GERDA Rate @ Q  = 2.2  10 -2 cts/(keV kg  y) HdM Rate @ Q  = 1.1  10 -1 cts/(keV kg  y) GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

21. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain NEW: spectrum for enr G 39 Ar: 1.01 Bq/kg from WARP NIM A 574:83-88,2007 42 Ar spectrum normalized to peak assumin homogeneous distribution 76 Ge: 1.74 ·10 21 y from HdM ref. NIM A 522,371-406, 2004 GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

22. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain LArGe GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

23. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain LArGe GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

24. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain LArGe GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

25. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain Background suppression by LAr instrumentation 228 Th Q  : R ~ 10 4 GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

26. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain 42 Ar spike in LArGe Added 42 Ar activity ~ 5 Bq GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

27. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain GERDA phase II: BEGe detectors 0  -like  -bgd DEP 89 11% - Low capacitance  high energy resolution.  E ~ 1.6 keV @ 1.332 MeV - Increased field near electrode  improved - S/B rejection capability by ID event topologies - Pulse Shape cuts accepting 90 % of 232 Th DEP - (mostly Single Site Events  0  -like) - ~10% survival of the g-line 212 Bi line (mostly - Multi-Site Events   -like) GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

28. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain GERDA phase II: BEGe detectors 3 nat Ge + 4 depl Ge BEGe detectors produced and tested in 2009-2010 in vacuum cryostat: all show excellent resolution (1.6 keV @ 1332 keV) and Pulse Shape discrimination performances depl GeO 2 : depl Ge (6N) crystal slice GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

29. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II. GERDA phase II: BEGe detectors 3 nat Ge + 4 depl Ge BEGe detectors produced and tested in 2009-2010 in vacuum cryostat: all show excellent resolution (1.6 keV @ 1332 keV) and Pulse Shape discrimination performances

30. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain GERDA phase II: enr Ge 97 % of the available 37.5 kg of enr Ge is now 6N material. The integrated exposure to cosmic ray is 5.2 days. All the material was stocked underground. Contract with the industrial partner to grow enr Ge crystals & produce BEGe diodes following the process of depl BEGe: signed. Current schedule: Phase II detectors produced and tested by Summer 2013. GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

31. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain Conclusions and future plans GERDA is taking data since June 2010 Phase I detectors perform well: –LC < 50 pA and stable –  E @ 2.614 keV 208 Tl: (3.6 – 6.0) keV Background: –Unexpected 42 Ar, but background from 42 K aviodable –Th/U for nat Ge smaller than in previous 0  experiments –At Q  nat Ge (1839-2239 keV): 0.06 ± 0.02 cts/(keV kg·y) –At Q  enr Ge < 0.06 cts/(keV kg·y) (90 % C.L.) –For enr Ge observed spectrum well reproduced by overlapping of 39 Ar, 2  of 76 Ge and 42 Ar Deployment of 8 enr Ge detectors by the end of 2011 Instrumentation of LAr in GERDA GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II.

32. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain B = 10 -3 cts/(keV  kg  y) B OREXINO GERDA B = 10 -6 cts/(keV  kg  y) ! GERDA’s goals Present status Deign Conclusions Bcg for nat Ge Bcg for enr Ge LArGe GD Phase II. GERDA vs B OREXINO

33. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain Backup slides

34. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain M= detector mass (active) t= measurement time b= background  E= energy resolution No bg: With bg: Backup slides 0 

35. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain Bologna, 20th September 2010 Shroud MS Shroud/Mini Shroud Outer shroud: diameter 760 mm Mini shroud: diameter 115 mm Many field configurations tested! Backup slides Run 10 with Mini Shroud

36. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain 13/12/2015TAUP 2011- Munich36 3 nat Ge no M Attrack ions to M run1 4 10 12 3 nat Ge With M 3 enr Ge With M 3 nat Ge With M 14 M’ 0V S 0V M 0V S 0 V  h+700 M 0V S 3.0 kV  h +700 M 0V S 0 V  h 0 no M Tested several electrostatic and shields config Reverted bias Run 3 w/o M

37. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain Backup slides LArGe

38. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain LArGe Backup slides

39. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain LArGe Backup slides

40. Half Day IoP Meeting: Neutrinoless Double Beta Decay, 12.10.2011 University College London, Great Britain LArGe Backup slides