1. February 21, 2005 The AGATA Week1 Overview of GRETINA Status I-Yang Lee Lawrence Berkeley National Laboratory The AGATA Week, 21-25th February 2005, GSI

2. February 21, 2005 The AGATA Week2 Outline Physics opportunities High lights of recent achievements Plan for 2005 Schedule and cost Management structure

3. February 21, 2005 The AGATA Week3 Capabilities of a 4   -ray tracking detector  Resolving power: 10 7 vs. 10 4 –Cross sections down to ~1 nb Most exotic nuclei Heavy elements (e.g. 253,254 No) Drip-line physics High level densities (e.g. chaos)  Efficiency (high energy) (15% vs. 0.5% at E  =15 MeV) –Shape of GDR –Studies of hypernuclei  Efficiency (slow beams) (48% vs. 8% at E  =1.3 MeV) –Fusion evaporation reactions  Efficiency (fast beams) (48% vs. 0.5% at E  =1.3 MeV) –Fast-beam spectroscopy with low rates -> RIA  Angular resolution (0.2º vs. 8º) –N-rich exotic beams Coulomb excitation –Fragmentation-beam spectroscopy Halos Evolution of shell structure Transfer reactions  Count rate per crystal (100 kHz vs. 10 kHz) –More efficient use of available beam intensity  Linear polarization  Background rejection by direction

4. February 21, 2005 The AGATA Week4 Advantages of  - ray Tracking High position resolution High efficiency High P/T High counting rate Background rejection Large recoil velocity – Fragmentation – Inverse reaction Low beam intensity High background rate – Beam decay – Beam impurity For Radioactive Beam Experiments

5. February 21, 2005 The AGATA Week5 Important Features of GRETINA Better position Resolution – 2 mm vs. 20 mm –High recoil velocity experiments Higher efficiency for high energy gamma rays –Giant resonances studies Compactness – ¼ GRETA is comparable or better than Gammasphere –Use with auxiliary detectors, recoil separators etc. GRETINA = ¼ GRETA

6. February 21, 2005 The AGATA Week6 Physics Opportunities with GRETINA How does nuclear shell structure and collectivity evolve in exotic n-rich nuclei? What is the influence of increasing charge on the dynamics and structure for the heaviest nuclei? How do the collective degrees of freedom and shell structure evolve with the excitation energy and angular momentum? What are the characteristics of the Giant Dipole Resonances built on superdeformed states and loosely bound nuclei?

7. February 21, 2005 The AGATA Week7 Recent Achievements Received CD1 approval – start design phase Developed design concept for mechanical support Received 3-crystal detector prototype III – Extensive testing with sources and beam Analyzed in-beam test results of prototype II Set up a data acquisition system Finalized detector module design Written requirement documents MOU’s signed with collaborating institutions Carried out safety and risk analysis CD0: Approve mission need CD1: Approve preliminary baseline rangeCD2: Approve performance baseline range CD3: Approve start of constructionCD4: Approve start of operation

8. February 21, 2005 The AGATA Week8 Concept of Mechanical Support Two quarter-spheres 17 detector mounting positions Allow translation and rotation Wedge plate for detector alignment Tool for detector installation Movable among laboratories (e.g. ANL, LBNL, MSU, ORNL)

9. February 21, 2005 The AGATA Week9 Three-crystal Prototype Tests performed Mechanical dimension Temperature and LN holding time Energy resolution Singles and preliminary coincidence scan In-beam measurements  Tapered hexagon shape  Highly segmented6  6 = 36  Close packing of 3 crystals  111 channels of signal Received June 4, 2004 8 cm 9 cm 10 deg.

10. February 21, 2005 The AGATA Week10 Prototype Test Results (0,-50, ) Front Left Right Back Crystal A segments 1 and 4 Segment boundaryElectron drift velocity In-beam measurements Signal shapes Under analysis

11. February 21, 2005 The AGATA Week11 Detector Module Design Design Choices 4 crystals per cryostat Warm FETs Reasons  Simpler geometry – 2 types of crystal, one cryostat  Easier FET replacement – 1 day vs. 9 days  Higher availability – near 100% vs. 85%  Lower price – $400k cost difference, with one more crystal

12. February 21, 2005 The AGATA Week12 Detector Geometry Packing scheme: 12 pentagons, 120 hexagons Pentagon size:  = 5.2%, fit a OD = 1.7” tube Ge crystals:  = 81.1% Target-to-crystal distance: r = 185 mm Packing schemeOptimization of shapesOptimization of distance  Geant4 program from Dino Bazzacco and Enrico Farnea

13. February 21, 2005 The AGATA Week13 Crystal Shapes

14. February 21, 2005 The AGATA Week14 Data Acquisition System  Signal digitizer  Trigger/timing system  Network switch  Processing farm  Data storage Signal digitizer prototype 100 MHz, 12 bit Energy – trapezoidal filter – P/Z correction Leading edge time Constant fraction time Pulse shape Data Acquisition System Schematic Aux. Det. Trigger Global Trigger Module Signal Digitizers Local Trigger Module Network Switch Processing Farm 30 Crystals Data Storage 2.2 MB/s Aux. Det. Data 66 MB/s 75 dual Processors Workstations, Servers 6.9 MB/s 2.3 MB/s + Aux. Det. Data

15. February 21, 2005 The AGATA Week15 Electronics Produced twenty units of the 2nd version of the signal digitizer. Fifteen are in use. Added P/Z cancellation algorithm to FPGA. Studied the performance of Ge detector preamplifier Tested Ge signal cables and connectors Completed draft of requirement document Before P/Z After P/Z

16. February 21, 2005 The AGATA Week16 Detector Testing System  Use 15 prototype DSP boards in VME crate to acquire data from all 111 channels of prototype detector  Acquisition rate > 8 Mbytes/sec  Data stored to a redundant disk array (2 Tbytes) over Gigabit network  Three data processing computers  Online histogramming during in-beam test  Offline analysis programs Setup for detector testing

17. February 21, 2005 The AGATA Week17 Computing Requirements  Assumptions – Movable among labs, expandable to more detectors  Performance Requirements – Process 20,000 gamma/sec, store 10 Mbytes/sec  Data Processing Components – Readout, event building, signal decomposition, tracking  Services – Controls, configuration management, online monitoring, data archiving

18. February 21, 2005 The AGATA Week18 Pulse Shapes with n-damage Pulse shapes from an undamaged detector (solid) and a neutron damaged detector after 10 10 n/cm 2 (dashed) Neutrons cause: 1)Reduction of charge collection efficiency 2)Residual charge in neighboring segments

19. February 21, 2005 The AGATA Week19 Neutron Damage effects  Degradation in E resolution occurs for < 100 cm, before correction and for <30 cm, after correction.  But only for < 17 cm position resolution becomes worse than 1 mm. A measurable effect of neutron damage on position resolution is never reached before annealing is required for energy resolution!

20. February 21, 2005 The AGATA Week20 Impurity Concentration Impurity => Space Charge =>Electric Field => Drift velocity => Pulse shape Impurity concentration is not constant in the crystal. From the manufacturer (z-variation)  V op = 5000 V Crystal A:  = (0.45 _ 1.5 ) x 10 10 a/cm 3  V fd = 2500 V Crystal B:  = (0.76 _ 1.2 ) x 10 10 a/cm 3  V fd = 2000 V Crystal C:  = (0.83 _ 1.8) x 10 10 a/cm 3  V fd = 3750 V Impurity concentration from  = 0 to  = 1.4 x 10 10 a/cm 3. Position resolution has been calculated. The capability of reconstructing the interaction position is not affected, if the impurity concentration is known with accuracy of:  = 0.75 x 10 10 atoms/cm 3 => 1 mm

21. February 21, 2005 The AGATA Week21 Improve Tracking Speed  Optimal permutation sequence –Track energy ordered interactions (Learning mode) –Arrange permutation by success rate –Track with learned order of permutation (production mode) 1.33 MeV, N = 7 7! = 5040 Permu. Event 3.4% 50% 5.0% 59% 7.0% 64% 8.4% 65% 1 2 3 5 6 7 4 1 2 3 7 5 6 4 1 2 3 5 7 6 4 1 3 2 5 6 7 4 1 2 3 6 5 7 4 1 2 4 5 7 6 3 1 2 6 5 7 4 3 1 2 5 4 6 7 3 1 2 6 4 5 7 3 1 2 5 7 4 6 3

22. February 21, 2005 The AGATA Week22 Plan for 2005  Receive CD2A/3A approval for detector  Receive and approve drawings of the 4-crystal detector module and award contract  Complete design of the Mechanical Support Structure  Complete design of the Liquid Nitrogen System  Complete analysis of in-beam data of prototype III  Finalize Electronics Requirement Document  Finish electronics R&D – preamp, trigger etc.  Finalize Computing System Requirement Document  Continue signal decomposition and tracking algorithm developments

23. February 21, 2005 The AGATA Week23 Schedule (Fiscal Years)

24. February 21, 2005 The AGATA Week24 GRETINA Cost (Jan. 04) Item Cost (M$) Mechanical 0.91 Detector6.95 Electronics 1.52 Computer 1.15 Assembly 0.18 Management2.22 Safety0.12 Sub total 13.05 Contingency2.85 (22%) Escalation1.10 Total (TEC) 17.0 Includes overhead Does not include R&D and scientific efforts

25. February 21, 2005 The AGATA Week25 Management Structure

26. February 21, 2005 The AGATA Week26 Collaborating Institutions Argonne National Laboratory –Trigger system –Calibration and online monitoring software Michigan State University –Detector testing Oak Ridge National Laboratory –Liquid nitrogen supply system –Data processing software Washington University –Target chamber Role defined by MOU’s

27. February 21, 2005 The AGATA Week27 Management Advisory Committee Don Geesaman, Argonne National Laboratory Konrad Gelbke, Michigan State University James Symons, (Chair) Lawrence Berkeley National Laboratory Glenn Young, Oak Ridge National Laboratory

28. February 21, 2005 The AGATA Week28 Gretina Advisory Committee Con Beausang, Yale University Doug Cline, University of Rochester Thomas Glasmacher, Michigan State University C. Kim Lister, Argonne National Laboratory Augusto Macchiavelli, Lawrence Berkeley Laboratory David Radford(Chair), Oak Ridge National Laboratory Mark Riley, Florida State University Demetrios Sarantites, Washington University Kai Vetter, Lawrence Livermore National Laboratory

29. February 21, 2005 The AGATA Week29 Working Groups PhysicsM. A. Riley Detector A. O. Macchiavelli Electronics D. C. Radford Software M. Cromaz Auxiliary Detectors D. G. Sarantites ANL, LANL, LBNL, LLNL, NRL, ORNL, FSU, Georgia Tech, MSU, Miss. SU, Purdue, U. Mass. Lowell, Rochester, Notre Dame, Vanderbilt, Wash. U., Yale ANU, CEA Saclay, Cologne, Daresbury, CNEA-UNSAM, CSNSM, Guelph, IFIC Valencia, INFN Podava, INFN Milano, Jyväskylä, Keele, KTH RIT, Liverpool, Lund, Manchester, Paisley, S. Paulo, Surry, TRIUMF, Tsinghua, TU Munich, Toronto, York, Uppsala, Warsaw

30. February 21, 2005 The AGATA Week30 Working Group Meetings Detector – March 19-20, 2004, ORNL Software –June 22-23, 2004, LBNL Electronics –July 24-25, 2004, ANL

31. February 21, 2005 The AGATA Week31 Summary Received CD1 – Started design phase No technical show stoppers Project on schedule and within cost so far Construction starts in 2007 Completion in 2010

32. February 21, 2005 The AGATA Week32 Summary Collaboration with AGATA has benefited GRETA/GRETINA We would like to continue and expand the collaboration Software working group meeting on signal decomposition ~ May 2005 Postdoc position available at Berkeley