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AGATA; status, plans and opportunities. John Simpson Nuclear Physics Group Daresbury Laboratory. Dr Andy Boston ajboston@liv.ac.uk. AGATA The A dvanced Ga mma Ray T racking A rray at Radioactive Ion Beam facilities. Introduction: The AGATA project
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AGATA; status, plans and opportunities John Simpson Nuclear Physics Group Daresbury Laboratory Dr Andy Boston ajboston@liv.ac.uk
AGATAThe Advanced Gamma Ray Tracking Array at Radioactive Ion Beam facilities • Introduction: The AGATA project • Current status of the AGATA; towards the “demonstrator” • Exploitation of AGATA; demonstrator and beyond Next generation g-ray spectrometer based on gamma-ray tracking First “real” 4 germanium array no Compton suppression shields Versatile spectrometer with very high efficiency and excellent spectrum quality for radioactive and high intensity stable beams
Experimental conditions and challenges FAIR SPIRAL2 SPES REX-ISOLDE EURISOL ECOS • Low intensity • High backgrounds • Large Doppler broadening • High counting rates • High g-ray multiplicities High efficiency High sensitivity High throughput Ancillary detectors Need instrumentation
AGATA(Design and characteristics) 4-array for Nuclear Physics Experiments at European accelerators providing radioactive and high-intensity stable beams Main features of AGATA Efficiency: 43% (M=1) 28% (M =30) today’s arrays ~10% (gain ~4) 5% (gain ~1000) Peak/Total: 58% (M=1) 49% (M=30) today ~55% 40% Angular Resolution:~1º FWHM (1 MeV, v/c=50%) ~ 6 keV !!! today ~40 keV Rates: 3 MHz (M=1) 300 kHz (M=30) today 1 MHz 20 kHz • 180 large volume 36-fold segmented Ge crystals in 60 triple-clusters • Digital electronics and sophisticated Pulse Shape Analysis algorithms allow • Operation of Ge detectors in position sensitive mode -ray tracking
The AGATA CollaborationMemorandum of Understanding 2003-07 Research and Development phase Bulgaria: Univ. Sofia Denmark: NBI Copenhagen Finland: Univ. Jyväskylä France: GANIL Caen, IPN Lyon, CSNSM Orsay, IPN Orsay, CEA-DSM-DAPNIA Saclay, IreS Strasbourg Germany: GSI Darmstadt, TU Darmstadt, Univ. zu Köln, LMU München, TU München Hungary: Debrecen Italy: INFN and Univ. Firenze, INFN and Univ. Genova, INFN Legnaro, INFN and Univ. Napoli, INFN and Univ. Padova, INFN and Univ. Milano, INFN Perugia and Univ. Camerino Poland: IFJ PAN Krakow, SINS Swierk, HIL & IEP Warsaw Romania: NIPNE & PU Bucharest Sweden: Chalmers Univ. of Technology Göteborg, Lund Univ., Royal Institute of Technology Stockholm, Uppsala Univ. UK: Univ. Brighton, STFC Daresbury, Univ. Liverpool, Univ. Manchester, Univ. Paisley, Univ. Surrey, Univ. York Turkey: Univ. of Ankara, Istanbul University
The First Step:The AGATA DemonstratorObjective of the final R&D phase 2003-2008 1 symmetric triple-cluster 5 asymmetric triple-clusters 36-fold segmented crystals 540 segments 555 digital-channels Eff. 3 – 8 % @ Mg = 1 Eff. 2 – 4 % @ Mg = 30 Full EDAQwith on line PSA and g-ray tracking In beam Commissioning Technical proposal for full array Cost ~ 6 M €
Ingredients ofg-Tracking 4 1 Identified interaction points Reconstruction of tracks e.g. by evaluation ofpermutations of interaction points Highly segmented HPGe detectors (x,y,z,E,t)i g · · Pulse Shape Analysisto decomposerecorded waves · · 2 3 Digital electronics to record and process segment signals reconstructed g-rays
AGATA Detectors • Symmetric detectors • 3 delivered • Asymmetric detectors • 15 ordered (4 accepted, 7 in 2007) • Preamplifiers available • Core (Cologne); Segment (Ganil & Milano) • Test cryostats for characterisation • 3 delivered • 2 ordered (1 delivered) • Triple cryostats • 4 (soon 5) ordered • 1st expected May 2007 Hexaconical Ge crystals 90 mm long 80 mm max diameter 36 segments Al encapsulation 0.6 mm spacing 0.8 mm thickness 37 vacuum feedthroughs
AGATA triple-detector module 3 encapsulated Ge crystals in one cryostat 111 preamplifiers with cold FET ~230 vacuum feedthroughs LN2 dewar, 3 litre, cooling power ~8 watts First prototype summer 2005
AGATA triple-detector module Planning for 2007: First asymmetrictriple module in summer 2007 (In-beam) tests using “standard” digital electronics 3 encapsulated Ge crystals in one cryostat 111 preamplifiers with cold FET ~230 vacuum feedthroughs LN2 dewar, 3 litre, cooling power ~8 watts
AGATA Design and Construction 180 geometry defined Conceptual design of 180 array done Details of HV etc. agreed, GSI test Design of AGATA demonstrator for LNL final stages Flanges manufacture started Assembly in LNL, 2007
Characteristation and Scanning Comparison of real and calculated pulse shapes. Validate codes. Coincidence scan for 3D position determination Three symmetric capsules scanned in Liverpool 288keV 374keV 662keV Commissioning of further scanning systems at Orsay and GSI Scan of an asymmetric capsule in Liverpool Scan of the 3rd symmetric capsule
AGATA s002 & s003 comparison (prelim) A B C D E F 1 2 3 4 5 6
I Geometry II Potential Elec field III Drift velocities IV Weighting fields AGATA symmetric crystal simulation Electric Field Simulations : MGS • Electric field simulations have been performed and details comparisons have been made with experimental pulse shape data.
Pulse-Shape Analysis: current status Results from the analysis of an in-beam test with the first triple module, e.g. Doppler correction of gamma-rays using PSA results REACTION CHANNEL: (d,p) 1382 keV PsaSegDet Results obtained with Grid SearchPSA algorithm (R.Venturelli et al.) Many different methods are under development
Segment level processing: energy, time Detector level processing: trigger, time, PSA Global level processing: event building, tracking, software trigger, data storage
AGATA Digitiser Module36+1 channels, 100 MhZ, 14 bits(Strasbourg - Daresbury – Liverpool) • Mounted close to the Detector 5-10 m • Power Dissipation around 400W • Water Cooling required • Testing in Liverpool • (December 2006) • Production in progress • (for 18 modules) Prototype Segment Board (2 boards per crystal)
Status and Evolution • Demonstrator commissioning at LNL late 2008 • First physics campaign at LNL in 2009 further proposals from GANIL, GSI • LoI for construction phase signed in 2005 to allow bids for new funds from 2006 (D, I) • MoU for AGATA construction from 2008 • Start completion in 2008, 1p in possible in ~2011 • Rate of construction depends on production capability and financing • Stages of physics exploitation, facility development
Schematics of the mounting frame holding (up to) 15 clusters AGATA demonstrator at Legnaro (2008-09) 5 triple clusters coupled to PRISMA Peak efficiency 3 – 8 % @ Mg = 1 2 – 4 % @ Mg = 30
AGATA demonstrator at Legnaro Principal physics opportunities : High-spin spectroscopy of moderately neutron-rich nuclei produced in deep-inelastic reactions Good experience from CLARA + Prisma Heavy-ion beams from PIAVE + ALPI with suitable intensities and energies
AGATA demonstrator at GANIL(~2010/11) Main physics opportunities: • Spectroscopy of heavy elements towards SHE • Gamma-ray spectroscopy of neutron-rich nuclei populated in Deep Inelastic Reaction (with the GANIL specific aspects) • Gamma-ray spectroscopy with reactions at intermediate energies (up to 50 A.MeV) • Classical high-spin physics and exotic shapes Range of beams, fragmentation, SPIRAL, direct beam line
AGATA-15 at the GSI-FRS Forward Quadrant with 45 crystals in 15 triple-clusters b = 0 b = 50 % v/c = 0 v/c = 0.5
AGATA “post-demonstrator” at GSI-FRS“Test Bench” for HiSpec (~2011) Main physics opportunities: Gamma-ray spectroscopy with reactions • at relativistic energies (> 50 A.MeV) Coulomb excitation, few nucleon removal etc. • with slowed-down beams (10-20 A.MeV) direct reactions, inelastic scattering
More Information AGATA web page http://www.gsi.de/agata/ Talks from last AGATA week ORSAY January 2007 http://www.csnsm.in2p3.fr/groupes/strucnuc/AGATAWEEK/agataweek.html