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John Simpson Nuclear Physics Group Daresbury Laboratory

The AGATA project. John Simpson Nuclear Physics Group Daresbury Laboratory. NUSTAR ’05 University of Surrey January 2005. Agata. John Simpson Nuclear Physics Group Daresbury Laboratory. AGATA The A dvanced Ga mma Ray T racking A rray. AGATA the ultimate gamma-ray spectrometer!.

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John Simpson Nuclear Physics Group Daresbury Laboratory

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  1. The AGATA project John Simpson Nuclear Physics Group Daresbury Laboratory NUSTAR ’05 University of Surrey January 2005

  2. Agata John Simpson Nuclear Physics Group Daresbury Laboratory

  3. AGATAThe Advanced Gamma Ray Tracking Array AGATA the ultimate gamma-ray spectrometer! Next generation spectrometer based on gamma-ray tracking Based on years of worldwide R&D No suppression shields 4 germanium array Very high efficiency and spectrum quality Stable, radioactive beams, low-high velocities

  4. Shape coexistence Transfermium nuclei 100Sn 48Ni 132+xSn 78Ni New challenges in Nuclear Structure • Shell structure in nuclei • Structure of doubly magic nuclei • Changes in the (effective) interactions • Proton drip line and N=Z nuclei • Spectroscopy beyond the drip line • Proton-neutron pairing • Isospin symmetry • Nuclear shapes • Exotic shapes and isomers • Coexistence and transitions • Neutron rich heavy nuclei (N/Z → 2) • Large neutron skins (rn-rp→ 1fm) • New coherent excitation modes • Shell quenching • Nuclei at the neutron drip line (Z→25) • Very large proton-neutron asymmetries • Resonant excitation modes • Neutron Decay

  5. Experimental conditions and challenges FAIR SPIRAL2 SPES REX-ISOLDE MAFF EURISOL HI-SIB • Low intensity • High backgrounds • Large Doppler broadening • High counting rates • High g-ray multiplicities High efficiency High sensitivity High throughput Ancillary detectors Need instrumentation

  6. AGATA(Advanced GAmma Tracking Array) 4-array for Nuclear Physics Experiments at European accelerators providing radioactive and high-intensity stable beams Main features of AGATA Efficiency: 40% (M=1) 25% (M =30) today’s arrays ~10% (gain ~4) 5% (gain ~1000) Peak/Total: 55% (M=1) 45% (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

  7. Idea of -ray tracking Large Gamma Arrays based on Compton Suppressed Spectrometers Tracking Arrays based on Position Sensitive Ge Detectors EUROBALL GAMMASPHERE AGATA GRETA e~ 10 — 5 % ( Mg=1 —Mg=30) e~ 40 — 20 % ( Mg=1 —Mg=30) Exogam, Miniball, SeGa: optimized for Doppler correction at low g-multiplicitiy e up to 20%

  8. Tracking requires: Good position determination from Digital pulse processing Previous/current projects: EU Vth Framework TMR `Development of –ray tracking detectors’ (6 EU countries) Miniball and Exogam (European collaborations) Mars, Italy UK Instrumentation grant ‘Digital Pulse Processing and –ray tracking’ (Liverpool, Surrey, Daresbury) GRETA, USA Proved that position resolution can be achieved, tracking algorithms developed, Highly segmented detectors developed Next step Build a sub array of few highly segmented detectors, prove tracking in real situations Scale up to full array, fund full array AGATA Europe (10 (12) countries, 42 (46) laboratories) Research and Development Phase Funding approved in France, Germany, Italy, UK, other countries bidding. GRETA U.S.A. Funded for development modules GRETINA U.S.A. Funded for 30 crystals

  9. The AGATA CollaborationMemorandum of Understanding 2003 Research and Development Bulgaria: Univ. Sofia Denmark: NBI Copenhagen Finland: Univ. Jyvaskyla France: GANIL Caen, IPN Lyon, CSNSM Orsay, IPN Orsay, CEA-DSM-DAPNIA Saclay, IreS Strasbourg Germany: HMI Berlin, Univ. Bonn, GSI Darmstadt, TU Darmstadt, FZ Jülich, Univ. zu Köln, LMU München, TU München 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: NINP and IFJ 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, CLRC Daresbury, Univ. Keele, Univ. Liverpool, Univ. Manchester, Univ. Paisley, Univ. Surrey, Univ. York Turkey Hungary

  10. 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 ACQwith on line PSA and g-ray tracking Test Sites: GANIL, GSI, Jyväskylä, Köln, LNL Cost ~ 7 M €

  11. The AGATA • RESEARCH and DEVELOPMENT PHASE • Develop 36 fold segmented encapsulated detector of right shape • Develop cryostat for groups “clusters” of these detectors • Develop digital electronics (700 channels) • Finalise signal algorithms for energy, position and time • Develop tracking algorithms • Build demonstration unit to prove tracking in real situations • Write technical proposal for full array

  12. 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

  13. AGATA Detectors 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 3 encapsulated crystals 111 preamplifiers with cold FET ~230 vacuum feedthroughs LN2 dewar, 3 litre, cooling power ~8 watts

  14. AGATA Prototypes • Symmetric detectors • 3 ordered, Italy, Germany • 3 delivered • Acceptance tests in Koln • 2 work very well • 3rd under test First results very good: 36 outer contacts 0.9-1.1keV at 60keV and 1.9-2.1keV at 1.3MeV Core 1.2keV at 60keV and 2.1keV at 1.3MeV Cross talk less than 10-3

  15. AGATA Prototypes Full scan of first in Liverpool Assembly of triple cryostat (CTT) Cluster ready by March 2005 Asymmetric detectors for the 180 geometry • 8 ordered in 2004 • 4 to be ordered in 2005 • delivery starts end 2005 First triple cryostat in Cologne

  16. AGATA Design and Construction GRETINA

  17. The 4 180 detector Configuration Ge crystals size: length 90 mm diameter 80 mm 180 hexagonal crystals 3 shapes 60 triple-clusters all equal Inner radius (Ge) 25 cm Amount of germanium 374 kg Solid angle coverage 78 % Singles rate ~50 kHz 6480 segments Efficiency: 39% (Mg=1) 25% (Mg=30) Peak/Total: 53% (Mg=1) 46% (Mg=30) http://agata.pd.infn.it/documents/simulations/comparison.html

  18. Segment level processing: energy, time Detector level processing: trigger, time, PSA Global level processing: event building, tracking, software trigger, data storage

  19. Detector characterisation Scanning with collimated source to characterise rise time responses Detector scanned with collimated source

  20. First AGATA detector being scanned in Liverpool • Liverpool System • Parker linear positioning table • Pacific scientific stepper motors • 0.3mCi 137Cs • 2mm steps collimator • Singles/coincidence 8 NaI system • GRT4 cards Preliminary results Core response to 662keV Scanning in progress

  21. PSA • Apply and test Genetic Algorithm on measured data with the AGATA prototypes • Develop new and specialised algorithms • Implement for on-line analysis • Gamma-neutron differentiation • Detector characterisation • Crystal scanning for pulse-shape data base construction • Simulation of charge carrier transport • Test neutron damage on PSA efficiency • γ-tracking • Optimise and couple the different tracking algorithmsfor improved AGATA performance • Determine the impact on AGATA performance of the use of additional detectors • Determine the AGATA response to simulated physics events

  22. Timescale • Five year research and development phase of AGATA • Start January 2003 ---end December 2007 • First three symmetric capsules expected mid 2004  • Test individual as 3-unit module by Easter 2005 • Start ordering asymmetric capsules in 2004  • First asymmetric cluster end 2005 • Test first crystals/ modules with “existing electronics” • Electronics and DA required mid 2006 • Time for R&D, GUI, algorithms PSA, tracking… • Test sub array 2007

  23. Status and Evolution • Demonstrator ready in 2007 • Next phases discussed in 2005-2006 • New MoU and bids for funds in 2007 • Start construction in 2008 • Rate of construction depends on production capability • Stages of physics exploitation, facility development

  24. The Phases of AGATA-180

  25. 5 Clusters 1p 3p 55 Clusters 4p Array The Phases of AGATA-180

  26. 5 ClustersDemonstrator 1 The Phases of AGATA 2007 Peak efficiency 3 – 8 % @ Mg = 1 2 – 4 % @ Mg = 30 Replace/Complement GSI FRS RISING LNL PRISMA CLARA GANIL VAMOS EXOGAM JYFL RITU JUROGAM Main issue is Doppler correction capability  coupling to beam and recoil tracking devices Improve resolution at higher recoil velocity Extend spectroscopy to more exotic nuclei

  27. 15 Clusters 1p b = 0 b = 0.5 2 The Phases of AGATA The first “real” tracking array Used at FAIR-HISPEC, SPIRAL2, SPES, HI-SIB Coupled to spectrometer, beam tracker, LCP arrays … Spectroscopy at the N=Z (100Sn), n-drip line nuclei, …

  28. 45 Clusters3p 3 The Phases of AGATA Efficient as a 120-ball (~20 % at high g-multiplicity) Ideal instrument for FAIR / EURISOL Also used as partial arrays in different labs Higher performance by coupling with ancillaries

  29. 60 Clusters4p 4 The Phases of AGATA Full ball, ideal to study extreme deformationsand the most exotic nuclear species Most of the time used as partial arrays Maximum performance by coupling to ancillaries

  30. Long Range Plan 2004Recommendations and priorities … In order to exploit present and future facilities fully and most efficiently, advanced instrumentation and detection equipment will be required to carry on the various programmes. The project AGATA, for a 4p-array of highly segmented Ge detectors for g-ray detection and tracking, will benefit research programmes in the various facilities in Europe. NuPECC gives full support for the construction of AGATA and recommends that the R&D phase be pursued with vigour.

  31. AGATANew physicsReveal the inner secrets of the atomic nucleus Tracking Arrays based on Position Sensitive Ge Detectors AGATA GRETA e~ 40 — 20 % ( Mg=1 —Mg=30)

  32. The Second AGATA Week 21-25th February 2005 GSI All welcome AGATA web page http://www-w2k.gsi.de/agata/

  33. The Management

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