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Overview of GRETINA Status

Overview of GRETINA Status. I-Yang Lee Lawrence Berkeley National Laboratory The AGATA Week, 21-25th February 2005, GSI. Outline. Physics opportunities High lights of recent achievements Plan for 2005 Schedule and cost Management structure.  Resolving power: 10 7 vs. 10 4

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Overview of GRETINA Status

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

  2. Outline • Physics opportunities • High lights of recent achievements • Plan for 2005 • Schedule and cost • Management structure The AGATA Week

  3. Resolving power: 107 vs. 104 Cross sections down to ~1 nb Most exotic nuclei Heavy elements (e.g. 253,254No) 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 Capabilities of a 4pg-ray tracking detector The AGATA Week

  4. Advantages of g- ray Tracking For Radioactive Beam Experiments • Large recoil velocity • Fragmentation • Inverse reaction • Low beam intensity • High background rate • Beam decay • Beam impurity • High position resolution • High efficiency • High P/T • High counting rate • Background rejection The AGATA Week

  5. Important Features of GRETINA GRETINA = ¼ GRETA • 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. The AGATA Week

  6. 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? The AGATA Week

  7. 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 range CD2: Approve performance baseline range CD3: Approve start of construction CD4: Approve start of operation The AGATA Week

  8. 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) The AGATA Week

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

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

  11. 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 The AGATA Week

  12. Detector Geometry • Packing scheme: 12 pentagons, 120 hexagons • Pentagon size: W = 5.2%, fit a OD = 1.7” tube • Ge crystals: W = 81.1% • Target-to-crystal distance: r = 185 mm Packing scheme Optimization of shapes Optimization of distance • Geant4 program from Dino Bazzacco and Enrico Farnea The AGATA Week

  13. Crystal Shapes The AGATA Week

  14. Data Acquisition System Schematic Local Trigger Module Signal Digitizers 2.2 MB/s 66 MB/s Global Trigger Module Processing Farm Network Switch 75 dual Processors 30 Crystals 6.9 MB/s Aux. Det. Trigger Workstations, Servers Aux. Det. Data Data Storage 2.3 MB/s + Aux. Det. Data 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 The AGATA Week

  15. 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 The AGATA Week

  16. 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 The AGATA Week

  17. 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 The AGATA Week

  18. Pulse Shapes with n-damage Pulse shapes from an undamaged detector (solid) and a neutron damaged detector after 1010 n/cm2 (dashed) • Neutrons cause: • Reduction of charge collection efficiency • Residual charge in neighboring segments The AGATA Week

  19. Neutron Damage effects • Degradation in E resolution occurs forl<100 cm, beforecorrection and forl<30 cm, after correction. • But only forl<17 cmposition resolutionbecomes worse than 1 mm. A measurable effect of neutron damage on position resolution is never reached before annealing is required for energy resolution! The AGATA Week

  20. Impurity Concentration Impurity => Space Charge =>Electric Field => Drift velocity => Pulse shape • Impurity concentration is not constant in the crystal. From the manufacturer (z-variation)  Vop = 5000 V Crystal A: r= (0.45 _ 1.5) x 1010 a/cm3  Vfd = 2500 V Crystal B: r = (0.76 _ 1.2 ) x 1010 a/cm3  Vfd = 2000 V Crystal C: r = (0.83 _ 1.8) x 1010 a/cm3 Vfd = 3750 V • Impurity concentration from r = 0 to r = 1.4 x 1010 a/cm3. • Position resolution has been calculated. • The capability of reconstructing the interaction position is not affected, if the impurity concentration is known with accuracy of: Dr= 0.75 x 1010 atoms/cm3 => 1 mm The AGATA Week

  21. 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% The AGATA Week

  22. 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 The AGATA Week

  23. Schedule (Fiscal Years) The AGATA Week

  24. GRETINA Cost(Jan. 04) Includes overhead Does not include R&D and scientific efforts Item Cost (M$) • Mechanical 0.91 • Detector 6.95 • Electronics 1.52 • Computer 1.15 • Assembly 0.18 • Management 2.22 • Safety 0.12 Sub total 13.05 Contingency 2.85 (22%) Escalation 1.10 Total (TEC) 17.0 The AGATA Week

  25. Management Structure The AGATA Week

  26. Collaborating Institutions Role defined by MOU’s • 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 The AGATA Week

  27. 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 The AGATA Week

  28. 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 The AGATA Week

  29. Working Groups • Physics M. 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 The AGATA Week

  30. Working Group Meetings • Detector • March 19-20, 2004, ORNL • Software • June 22-23, 2004, LBNL • Electronics • July 24-25, 2004, ANL The AGATA Week

  31. 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 The AGATA Week

  32. 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 The AGATA Week

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