AGATA status plans and opportunities Dr Andy Boston

AGATA; status, plans and opportunities Dr Andy Boston ajboston@liv. ac. uk John Simpson Nuclear Physics Group Daresbury Laboratory

AGATA The Advanced Gamma Ray Tracking Array at Radioactive Ion Beam facilities Ø Introduction: The AGATA project Ø Current status of the AGATA; towards the “demonstrator” Ø 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 SPIRAL 2 SPES REX-ISOLDE EURISOL ECOS • • • Low intensity High backgrounds Large Doppler broadening High counting rates High -ray multiplicities Need instrumentation High efficiency High sensitivity High throughput Ancillary detectors

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) Peak/Total: 58% (M =1) today ~55% 5% (gain ~1000) 49% (M =30) 40% Angular Resolution: ~1º FWHM (1 Me. V, v/c=50%) ~ 6 ke. V !!! today ~40 ke. V Rates: 3 MHz (M =1) 300 k. Hz (M =30) today 1 MHz 20 k. Hz • 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 Collaboration Memorandum 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, Ire. S 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 Demonstrator Objective 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 % @ M = 1 Eff. 2 – 4 % @ M = 30 Full EDAQ with on line PSA and -ray tracking In beam Commissioning Technical proposal for full array Cost ~ 6 M €

Ingredients of g-Tracking 1 Highly segmented HPGe detectors · · g · · 2 4 Identified interaction points (x, y, z, E, t)i Reconstruction of tracks e. g. by evaluation of permutations of interaction points Pulse Shape Analysis to decompose recorded waves 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 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 – Core (Cologne); Segment (Ganil & Milano) • Test cryostats for characterisation – 3 delivered – 2 ordered (1 delivered) • Triple cryostats – 4 (soon 5) ordered – 1 st expected May 2007

AGATA triple-detector module 3 encapsulated Ge crystals in one cryostat 111 preamplifiers with cold FET ~230 vacuum feedthroughs LN 2 dewar, 3 litre, cooling power ~8 watts First prototype summer 2005

AGATA triple-detector module Planning for 2007: First asymmetric triple 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 LN 2 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 3 D position determination Three symmetric capsules 374 ke. V 662 ke. V 288 ke. V scanned in Liverpool Commissioning of further scanning systems at Orsay and GSI Scan of an asymmetric capsule in Liverpool Scan of the 3 rd symmetric capsule

AGATA s 002 & s 003 comparison (prelim) A B C D E F 1 2 3 4 5 6

Electric Field Simulations : MGS I Geometry II Potential Elec field III Drift velocities AGATA symmetric crystal simulation IV Weighting fields • 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) Best result γ detector, seg. mult. 1 FWHM Full dataset Simulation FWHM Detector 32 ke. V 35 ke. V Segment 11. 1 ke. V 12 ke. V 5. 3 ke. V 5. 0 ke. V PSA 4. 8 ke. V Results obtained with 1382 ke. V Psa Seg Det Grid Search PSA 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 Module 36+1 channels, 100 Mh. Z, 14 bits (Strasbourg - Daresbury – Liverpool) • Mounted close to the Detector 5 -10 m • Power Dissipation around 400 W • 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 • Lo. I for construction phase signed in 2005 to allow bids for new funds from 2006 (D, I) • Mo. U for AGATA construction from 2008 • Start completion in 2008, 1 in possible in ~2011 • Rate of construction depends on production capability and financing • Stages of physics exploitation, facility development

AGATA demonstrator at Legnaro (2008 -09) 5 triple clusters coupled to PRISMA Schematics of the mounting frame holding (up to) 15 clusters Peak efficiency 3 – 8 % @ M = 1 2 – 4 % @ M = 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. Me. V) • Classical high-spin physics and exotic shapes Range of beams, fragmentation, SPIRAL, direct beam line

AGATA “post-demonstrator” array at GSI-FRS (~2010/11) LYCCA

AGATA-15 at the GSI-FRS Forward Quadrant with 45 crystals in 15 triple-clusters b = 0 b = 50 % v/c = 0. 5

AGATA “post-demonstrator” at GSI-FRS “Test Bench” for Hi. Spec (~2011) Main physics opportunities: Gamma-ray spectroscopy with reactions • at relativistic energies (> 50 A. Me. V) Coulomb excitation, few nucleon removal etc. • with slowed-down beams (10 -20 A. Me. V) 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. in 2 p 3. fr/groupes/strucnuc/AGATAWEEK/agataweek. html