1 / 57

Activity at LNL and SPES

Activity at LNL and SPES. L.Corradi Laboratori Nazionali di Legnaro – INFN, Italy. AN2000 2 MV. CN 7 MV. PIAVE HI Injector. The LNL accelerators. ALPI Linac 40 MVeq. Tandem XTU 15 MV. Transnational access. Open Calls for LoIs for the INFN research infrastructures May 2007.

elin
Download Presentation

Activity at LNL and SPES

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Activity at LNL and SPES L.Corradi Laboratori Nazionali di Legnaro – INFN, Italy Nupecc Meeting Catania, March 12, 2010

  2. AN2000 2 MV CN 7 MV PIAVE HI Injector The LNL accelerators ALPI Linac 40 MVeq Tandem XTU 15 MV

  3. Transnational access Open Calls for LoIsfor the INFN research infrastructures May 2007 50 LoIs 312 potential users from 15 countries (about 30% more than presented at the VI FP) E.Fioretto

  4. Nuclear structure research GASP CLARA AGATA demonstrator - High spin states - Collectivity and shell model - Isospin symmetries - Isospin mixing in N=Z nuclei - Spectroscopy at the dripline - Shell stability and evolution in neutron rich nuclei - Symmetries at the critical point - Rotational damping

  5. Reaction dynamics research PRISMA and PISOLO EXOTIC GARFIELD and 8πLP • Multinucleon transfer • - Nuclear superfluidity (pair transfer) • - Elastic and inelastic scattering • - Near and sub-barrier fusion - Multifragmentation at low excitation energies - Nuclear level density - Collective modes of excitations - Break up processes - Quasi elastic scattering with light ions produced in secondary reactions

  6. target MOT Fundamental interaction studies the TRAPRAD experiment : production and trapping of Fr isotopes LNL-FE-SI collaboration 18O+197Au Francium is the heaviest alkali, has a simple electronic structure and has enhanced P and T violation effects 18O beam I= 200 pnA I ~ 5x105 ions/sec trapped 8000 210Fr isotopes

  7. % distribution of beam on target among the different set-up’s LNL PAC Feb2006 average rejection factor for nuclear physics experiments over the last five years : 45-65% LNL PAC Feb2010

  8. Conventional array Segmented detectors g-ray tracking Energy (keV) The innovative use of detectors (pulse shape analysis, g-ray tracking, digital DAQ) will result in high efficiency (~40%) and excellent energy resolution Objective of the final R&D phase 2003-2008 5 asymmetric triple-clusters 36-fold segmented crystals 540 segments 555 digital-channels Eff. 3 – 7 % @ Mg = 1 Eff. 2 – 4 % @ Mg = 30 Full ACQwith on line PSA and g-ray tracking The AGATA DEMONSTRATOR Major issue (in the demonstration phase) is the Doppler correction capability  coupling to beam and recoil tracking devices PRISMA D.Bazzacco

  9. Present set up: 3 triple clusters 4th triple being installed now Original and Doppler-corrected spectra for the 847 keV 56Fe 2+  0+ lineDirection of recoils determined by the MCP Dante 547 keV (197Au) 847 keV ( 56Fe) 56Fe  197Au 220 MeV Dante+PSA 2.6 keV Dante+PSA 4.6 keV Original ~10 keV Original ~30 keV

  10. neutrons protons Physics program : evolution of magic numbers and collectivity in neutron rich nuclei, but not only… Proton drip-line More than 20 LoI: Highly Excited Collective Modes.Proton-rich mirror nuclei.Superdeformed states in A~40 proton-rich region.Order-Chaos transition in warm rotating nuclei.etc... Neutron drip-line Evolution of collectivity and Dynamical Symmetries in the rare earths n-rich nuclei Mix-symmetry states Quenching of the N=82 shell gap in n-rich nuclei N=50 shell gap: lifetime, and excited states Lifetimes in neutron-rich Ca isotopes Spectroscopy and lifetimes in the new region of deformationn-rich A~60, N~40 nuclei Lifetimes in the region of the island of inversion

  11. THE PRISMA SPECTROMETER + CLARA GAMMA ARRAY INFN exp. PRISMA (LNL,PD,TO,Na) INFN exp. GAMMA (LNL,PD,Fi,MI,Na,Pg) + broad Int. Collaboration (UK,F,D,Pl,Sp,Ro,Hr) PRISMA: a large acceptance magnetic spectrometer W  80 msr; Brmax = 1.2 Tm DA/A ~ 1/200 Energy acceptance ~±20%

  12. Multineutron and multiproton transfer channels near closed-shell nuclei 90Zr+208Pb Elab=560 MeV pure neutron pick-up channels Mass [amu] PRISMA spectrometer data GRAZING code calculations L.Corradi et al, J.Phys G36(2009)113101 (Topical Review)

  13. Near- and sub-barrier fusion reactions Precise measurements of fusion excitation functions allow to probe nuclear structure effects:multi-dimentional tunnelling, influence of surface vibrations and transfer channels on reaction dynamics understand synthesis of superheavy elements measure rates of reactions of astrophysical interest cross section measurements at far sub-barrier energies may probe the nuclear potential inside the Coulomb barrier A.M.Stefanini et al PRC78(2008)044607 A.M.Stefanini et al., PRC76(2007)014610

  14. 136Xe 96Zr 82Se 70Zn 64Ni 48Ca 36S 26Mg 40Ar 22Ne THE PRISMA + CLARA CAMPAIGN Grazing reactions as a tool to study n-rich nuclei To do that we used the most neutron-rich stable beams available at the Tandem/PIAVE-ALPI accelerator complex of LNL at energies 5-15% above the Coulomb barrier 14

  15. New points 58Cr Gamma softness in heavy Cr and Fe isotopes populated in 64Ni+238U at Elab=404 MeV Cr (-4p) N.Marginean et al., Phys. Lett. B 633(2006)696 dynamical symmetries • The R(E4/E2) ratio for the heavy Fe isotopes is very close to the 2.50 value characteristic of g-soft rotors • The value for the heavier Cr isotopes is also close to the same limit • 58Cr lies exactly at the 2.20 value predicted for the E(5) dynamical symmetry. The energies of the yrast band are in good agreement with the predictions of this symmetry. Transition probabilities are essential to decide whether 58Cr lies or not at the E(5) critical point.

  16. Lifetimes measurements in 48Ca+208Pb at Elab=310 MeV Differential Plunger Method comparison of deduced B(E2) with large scale shell model calculations J.J.Valiente-Dobon et al, PRL102(2009)242502

  17. AGATA Demonstrator/1Π Experimental program July 2013 GANIL/SPIRAL2 ~15TC June 2011  LNL6TC Dec 2011  GSI/FRS≥ 8TC AGATA D.+PRISMA AGATA @ FRS AGATA + VAMOS + EXOGAM Total Eff. ~6% Total Eff. > 10% Total Eff. > 20%

  18. GARFIELD+HECTOR Campaign • Temperature dependence of GDR • Isospin Mixing of N=Z nucleus 80Zr at high T • Dynamic Dipole in N/Z asymmetric reaction • Search for the Jacobi shape transition in light nuclei • Onset of the multi-fragmentation and the GDR Nuclear structure at finite temperature Coincident measurements : g +LCP + residues @ 5-20MeV/A PPAC or Phoswich Residues selection GARFIELD: 180 E-DE telescopes Light Charged Particles HECTOR: 8 Large BaF2 High-energy g-rays F.Gramegna, A.Bracco et al, LNL-MI collaboration

  19. GARFIELD+HECTOR set-up – GDR studies in hot and thermalized nuclei : damping of collective modes at finite temperature Two reactions – same compound 16O (130,250 MeV ) + 116Sn 132Ce* 64Ni (300,400,500 MeV) + 68Zn 132Ce* Agreement with thermal fluctuation model if and only if CN evaporation width is included Analysis of α particle spectra shows preequilibrium effects in 16O+116Sn Increase of GDR width is due to deformation effects GDR analysis with no preequilibrium effects in 64Ni+116Sn O. Wieland et al., PRL97(2006)012501

  20. GARFIELD : studies of response of silicon detectors - channelling effects and digital pulse shape DIGITAL PULSE SHAPE on 500μm Silicon The FAZIA Initiative 32S +27Al @ 474 MeV Final goal: build the full array for lower (SPIRAL2 / LNL / SPES) and higher energy (GANIL / LNS / FAIR / EURISOL / RIA) studies with exotic and stable beams. Ne F O N C B Be Randomimpingingions channelling spoils mass identification 300 μ 500 μ G.Poggi

  21. SPES ISOL facility • Cyclotron 750 μA,70 MeV (max) for protons in twoexit ports: • RIB - up to 300 μA p on UCx • Application - up to 500 μA Additional target station (special plants second priority) RIB or neutron production transport/beam cooler/separator High Resolution Mass Spectrometer 1/20000 Charge Breeder 1+  n+ UCx target station 1013 fission/s (PostAccelerator) G.Prete

  22. ALPI layout ALPI upgrade for SPES Optimum beta βo = 0.047 βo = 0.056 βo = 0.11 βo= 0.13 To be funded: 2 additional LowBeta Cryostats (CR1, CR2) a New buncher New magnetic lenses (upgrade from 20 to 30 T/m) Funded upgrade (2009) LowBeta CR3, new couplers 22

  23. The ALPI post accelerator Expected SPES energies • Superconductinglinac based on QW Resonators • 2003: Up graded to Veq ~ 40 MV - Nb/Cu sputtered cavities or bulk Nb cavities; 2009: 48 MV • Energies up to 10-12 MeV/A for A=130 beams

  24. Representative expected beams at SPES ionization efficiencies: (1+) 30% and (n+) 4% (1+) 90% and (n+) 12% for Kr and Xe, Transport efficiency 50%

  25. SPES SCHEDULE

  26. SPES technical design report

  27. Radioactive Beams Dynamical Dipole Yields Dynamical Dipole yield increases with asymmetry of fusing ions LOI SPIRAL2 Dynamic Dipole in172Yb  5MeV/A (onset energy for DDR) Information can be extracted on the symmetry energy term at low density S.Leoni Baran, Brink, Colonna, DiToro PRL87(2001)182501

  28. proton pick-up channels lead to neutron rich heavy mass nuclei proton stripping channels lead to neutron rich medium mass nuclei

  29. Multinucleon transfer reactions with neutron-rich beams possibility to populate nuclei via pick-up and stripping of both neutrons and protons probing (nn), (pp) and (np) correlations. Important for studies on pairing vibrations/rotations, nuclear superfluidity production of neutron rich isotopes GRAZING code calculations C.H.Dasso, G.Pollarolo, A.Winther, PRL73(1994)1907

  30. Near- and sub-barrier fusion reactions with exotic beams With the lower beam intensities of RIB, one can derive fusion barrier distributions by measuring excitation functions of quasi-elastic channels Key issues with RIB Enhanced effects of positive Q-value transfer channels Role of surface modes in nuclei with significant neutron excess F.Liang et al., PRC75(2007)054607 S.Mitsuoka et al, PRL99(2007)182701

  31. Some few remarks Nuclear structure and nuclear reactions with heavy ions are being investigated at near barrier energies with the TANDEM+ALPI+PIAVE accelerator complex of LNL Important developments have been made in complex detector systems (gamma arrays, tracking spectrometers, charge particle arrays) through which extensive studies have been and are being successfully performed in different areas The SPES project represents the most important step forward for nuclear physics research in Italy. Its completion will allow to perform challenging and significant studies in heavy ion physics with RIB’s

  32. The SPES project • Facility Approved for construction • Phase 1 - financed by INFN TANDEM XTU Experimental HALLS RIB Transport Line III Experimental HALL SPES LINAC ALPI Primary Beam: Cyclotron 300 μA,70 MeV (max) for protons in two exit ports for RIB Production Target: UCx multi-foil , up to 1013 fission s-1 Post-accelerator: PIAVE-ALPISuperconductive Linac up to 11 AMeV for A=130

  33. 1 2 H He 3 4 5 6 7 8 9 10 Li Be B C N O F Ne 14 15 11 12 13 16 17 18 Na Mg Al Si P S Cl Ar 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe 55 56 57 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn 87 88 89 104 105 106 107 108 109 110 111 112 Fr Ra Ac Rf Db Sg Bh Hs Mt Ionization methods at SPES Elements with bad volatility (NOT EXTRACTED) Surface Ionization Method Surface Ion source Photo Ionization Method Laser beam Plasma Ionization Method Laser Ion source Main fission 238U fragments Plasma Ion source

  34. UCx emissivity The SPES target prototype UCx target procuction Graphite Window UCx Disk Graphite Dumpers SPES target-ion-source Front End SEM Characterization Graphite Box

  35. SPES Target collaborations network TRIUMF- ISAC KEK- TRIAC ORNL- HRIBF SPES UNIPV UNIPD UNITN DCT- Structure and Transportation Engineering DIM- Mechanical Eng. DEI-IT – Eng. Chemistry DIM DIM DCT DEI Chemistry CONTROLS HANDLING DESIGN MATERIALS CERN- ISOLDE LNL GANIL-SPIRAL 2 Pavia Napoli Milano Catania ORSAY-ALTO Bologna Firenze LNS Padova UNIPA Nucl. Engin.

  36. PIAVE cryostat Present layout ISACII-like cryostats SPES layout PIAVE upgrade for SPES 38

  37. Multinucleon transfer reactions in the transactinide region Eurisol Project (key experiments) http://www.ganil.fr/eurisol/ Multinucleon transfer reactions are a promising tool to get access to very neutron rich heavy nuclei when using a neutron rich radioactive beam GRAZING calculations

  38. Quasielastic barrier distributions : role of particle transfer channels Exp. data : S.Mitsuoka et al, Phys.Rev.Lett.99,182701(2007) Calculations : G.Pollarolo, Phys.Rev.Lett.100,252701(2008)

  39. Charge NOT equilibrated all degree of freedom EQUILIBRATED Prompt Dipole Giant Dipole Resonance Temperature dependence of GDR width  damping of CN Reaction Dynamics  EOS GDR p vs n Dipole Resonance Emission from HOT nuclei density plot fusion CN dipole moment t=0 fm/c CN fusion

  40. pre equilibrium gspectra GDR analysis with NO pre-equilibrium effects GARFIELD + HECTOR experiment @ LNL Two reactions – same compound 16O (130,250 MeV ) + 116Sn 132Ce* 64Ni (300,400,500 MeV) + 68Zn 132Ce* aparticle spectra

  41. Last stage of the decay revealed by correlation functions p+12C d+ p+7Be E*=0.7, 2.3 MeV E*=2.3, 3.5 MeV E*= 2.2, 4.3, 5.6 MeV Primary yields can be obtained after Coulomb background subtraction

  42. GARFIELD & Ancillaries Pre-equilibrium emission in 16O+116Sn Measuring correlation functions Experiments with n-rich/poor systems @ LNL32S+58Ni and 32S+64Ni 14.5 AMeV R(q) probes space-time properties of source

  43. Multinucleon transfer reactions : from neutron poor to neutron rich nuclei LNL data GRAZING code calculations 44Ar + 208Pb E=320 MeV with (moderately n-rich) heavy ions one can populate (nn), (pp) and (np) channels with comparable strength

  44. Approaching 78Ni and 132Sn regions

  45. Neutron rich nuclei produced in the fission of 238U in 136Xe+238U at Elab=990 MeV N.Marginean et al., Phys. Rev. C80(2009)021301(R)

  46. Total cross sections successive transfer S.Szilner et al, Phys.Rev.C76(2007)024604

  47. MWPPAC IC PRISMA spectrometer – trajectory reconstruction • A physical event is composed by the parameters: • position at the entrance x, y • position at the focal plane X, Y • time of flight TOF • energy DE, E

  48. Population of neutron rich nuclei 64Ni+238U at Elab=390 MeV 58Fe most neutron-rich stable isotopes 54Cr possibility to make spectroscopic studies of neutron rich nuclei moderately far from stability 50Ti L.Corradi et al, Phys.Rev.C59(1999)261

  49. multinucleon transfer : experiment vs. theory data : LNL theory : GRAZING code and CWKB L.Corradi et al, J.Phys.G36(2009)113101 (Topical Review)

More Related