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Sara Pirrone EXOCHIM collaboration INFN-Sezione di Catania

11th INTERNATIONAL SPRING SEMINAR ON NUCLEAR PHYSICS “Shell Model And Nuclear Structure: achievements of the past two decades” in honor of Aldo Covello ISCHIA, MAY 12-16, 2014. Isospin Physics by CHIMERA detector. Sara Pirrone EXOCHIM collaboration INFN-Sezione di Catania.

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Sara Pirrone EXOCHIM collaboration INFN-Sezione di Catania

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  1. 11th INTERNATIONAL SPRING SEMINAR ON NUCLEAR PHYSICS “Shell Model And Nuclear Structure: achievements of the past two decades” in honor of Aldo Covello ISCHIA, MAY 12-16, 2014 Isospin Physics by CHIMERA detector Sara Pirrone EXOCHIM collaboration INFN-Sezione di Catania

  2. The multifaceted influence of the nuclear symmetry energyA.W. Steiner, M. Prakash, J.M. Lattimer and P.J. Ellis, Phys. Rep. 411, 325 (2005).

  3. EOS & Symmetry Energy AsyStiff AsySoft ρ0 = 0.16 fm-3 E(ρ,) = E(ρ,=0) + Esym(ρ)² ρ  ρnρp Esym() ≈ (/) γ< 1 Asysoft, γ≥ 1 Asystiff I.Bombaci and U.Lombardo PRC 44,1892 (1991)

  4. Example of Chimera coll. contribution to isospin physics studies • Study of the systems 124Sn+64Ni and 112Sn+58Ni @35 A.MeV. Neck emission, Time scale for fragment formation, fragment hierarchy, Dynamical fission(Chimera coll) LNS • Isospin dependence in the competition between incomplete fusion and dissipative binary reactions in 40Ca,48Ca + 40,48Ca, 46Ti @25 AMeV(Chimera coll.) LNS • Study of isospin diffusion in the reactions 124Sn+124Sn, 124Sn+112Sn, 112Sn+124Sn, 112Sn+112Sn @35 MeV.(MSU-Chimera coll.). LNS • Fast collinear partitioning of the 197Au + 197Au @15 A.MeV, system into three and four fragments of comparable size(Chimera coll.) LNS • Exploring the isospin dependence on decay from compound nucleus in the reactions 78,86Kr + 40,48Ca @10 A.MeV(Chimera-Indra coll.) LNS • Constraining the Symmetry Energy at Supra-Saturation Densities With Measurements of Neutron and Proton Elliptic Flow, Au+Au, 96Zr+96Zr and 96Ru+96Ru @400 A.MeV(AsyEos-Chimera coll.) GSI In progress…

  5. CHIMERA@LNS A. Pagano et al, Nucl. Phys. A 734 (2004) 504 A.Pagano et al., NPA734 (2004)

  6. CHIMERA Charge Heavy Ion Mass and Energy Resolving Array 30° T 1° Identification A, Z, E – Recostruction of event Dynamical range : from fusion, fusion-fission to multifragmentation reaction

  7. Selected Chimera Experiment @INFN-LNS on Reaction Dynamics & Isospin physics • TIMESCALE–DYNAMICAL FISSIONStudy of the systems124Sn+64Ni and 112Sn+58Ni (inverse) @ 35 A.MeV.Neck emission, Time scale for fragment formation, fragment hierarchy, Dynamical fission • ISODECExploring the isospin dependence on decay from compound nucleus in the reactions78,86Kr + 40,48Ca @10 A.MeV

  8. Study of the systems 112Sn + 58Ni (n-poor), 124Sn + 64Ni (n-rich)@ 35 AMeV Time scale for fragment formation, fragment hierarchy, Neck Emission - Dynamical fission

  9. n NECK PLF p TLF IMF TLF PLF Ternary and semiperipheral events selection 124,112Sn + 58,64Ni @ 35 AMeV ZP 3Mc6 *bred>0.6 ZT IMF , Z  3 VP Neck formation E.De Filippo et al. PRC71,44602 (2005)

  10. TIME SCALE: Emission Chronology by velocity correlation 124Sn+64Ni 35 MeV/A PLF TLF VREL VREL IMF prompt Relative velocities are expressed in relationship with the Viola velocity (pure Coulomb repulsion) Viola et al Nucl. Phys. A472, 318 (1987) E.De Filippo et al. PRC71,44602 (2005) vrel/vviola =1 SEQUENTIAL DECAY OF IMF FROM PLF (or TLF), t ≥ 120 fm/c (2,3) vrel/vviola≠ 1 NON-STATISTICAL EMISSION OF IMF , t ~ 40 fm/c (1 )

  11. 3 2 1 1 40 fm/c 2 80 fm/c 3 120 fm/c Emission chronology: light fragments are produced earlier (~40 fm/c) than heavier ones (~120 fm/c) TIME SCALE: Emission Chronology by velocity correlation 124Sn+64Ni35 MeV/A E.De Filippo et al, PRC86 014610 2012

  12. Correlations with IMFs (Z  8) isotopic properties n NECK 124Sn + 64Ni 35 A.MeV Be Li p TLF <N/Z> PLF C B The correlation shows that the greatest neutron enrichment is linked to greater deviations from Viola systematics, that is to fast prompt emission of IMF. We can select Dynamical emission Statistical emission 12 E.De Filippo et al. PRC71,44602 (2005)

  13. Dynamical and Sequenzial emission of IMF Dynamically emitted particles Statistically emitted particles Neutron rich system Neutron poor system n-rich system - Entrance channel memory effect - Reduction in staggering effect E.De Filippo et al, PRC86 014610 2012 13

  14. 124Sn+64Ni 35 A.MeV SMF - microscopic approach that describe the evolution of systems by Boltzmann- Nordheim-Vlasov transport equation. The model includes nuclear mean field dynamics and effect of fluctuations. V. Baran et al. Nucl. Phys. A730 329 (2004). DE Asy-stiff Asy-soft SE Stochastic Mean Field (SMF) + GEMINI calculation Primary fragments Dynamically emitted particles Data consistent with γ ≈ 1 Calculations performed by: M. Colonna E.De Filippo et al, PRC86 014610 2012

  15. Study of the systems 112Sn + 58Ni (n-poor), 124Sn + 64Ni (n-rich)@ 35 AMeV Time scale for fragment formation, fragment hierarchy, Neck Emission - Dynamical fission

  16. From early prompt neck fragmentation to PLF dynamical fission Ternary events associated to the emission of heavy fragments coming from PLF break-up/fission and appearing at a longer time of emission 3 2 1 Binary break-up • The time-scale of the process is one of the the signature among different mechanisms: • Early neck fragmentation (40-120 fm/c) • Dynamical fission (120-300 fm/c) • Statistical fission (>1000 fm/c) P. Russotto et. al. Phys. Rev. C81, 064605 (2010)

  17. Dyn/Stat Fission components for124Sn+64Niand112Sn+58Ni IMFs Cross-sections Probability ratio of dynamical and statistical fission components Dynamical component: enhanced in the n- rich system Statistical component: almost equal for n-rich, n-poor systems P. Russotto et al. , submitted, PRC (2014)

  18. The InKiIsSy (INverse KInematics ISobaric Systems-P.Russotto) Apr.2013 Size or Isospin effects? 124Xe+64Zn @ 35 AMeV -same mass of the n-rich 124Sn+64Ni system, -N/Z near to the n-poor 112Sn+58Ni system A new setup: the 4π CHIMERA + FARCOS 1° cluster prototype 4 telescopes 25 cm from the target lab  16-44 deg,   45 deg Analysis in progress…..

  19. FARCOS project Femptoscope ARray for COrrelation and Spectroscopy High energy and angular resolution (Δϑ<1°) Low thresholds ( <1 MeV/A): Pulse-shape on first Si layer for low energy experiments High counting rate (1KHz) Large Dynamic range (20MeV to 2GeV) Flexibility, Modularity, Trasportability Coupling to 4 detectors or spectrometers Integrated Electronics (GET)

  20. Study of the systems 78,86Kr + 40,48Ca @10 AMeV Isospin influence on the reaction and emission mechanism of IMF (Z≥3)

  21. ISODEC - Scientific Program ITA-FRA Collaboration Lea - Colliga • “ Isospin dependence(N/Z) of theformation and emission mechanism • of complex fragments (IMF, Z≥3) from CN to get information on: • level density, (thermal properties, E*, meffective) • fission barrier, (Symmetry, congruence and Wigner E terms) • viscosity, ( coupling collective – intrinsic modes, Fermi level)” • Stable Beams • -E475S@GANIL , with INDRA (2007) • -ISODEC@LNS , with CHIMERA (2010) • Next Exotic Beams • -Loi for SPES@LNL • -Next proposal for SPIRAL2@GANIL S. P. et al., Proc. of FUSION11, EPJ Web of Conf. 17, 16010 (2011) G. Politi et al., Proc. of CNR11 EPJ Web of Conf. 21, 02003 (2012) M.L.Commara et al., Proc. of IWM2011, EPJ Web of Conf. 11, 00022 (2012) S. P. et al.,Proc of ICRTNP2012, AIP Conf. Proc. 1524, 7-10 (2013)

  22. E475S INDRA @GANIL E= 5.5 AMeV 78, 82 Kr + 40 Ca118,122Ba* (~ 100 MeV) FF IMF • 3≤  ≤ 44° IC-Si-CsI • forward part • Energy, ang. Distr. RP • Charge distribution • Cross section decay mode • CN neutron rich (o) • 30% less fission (Z  14 ) • Less even-odd staggering of IMF ( 6 ≤ Z ≤ 12 ) Comparisons with statistical and dynamical models don’t reproduce completely the data, G. Ademard et al. PRC 83 (2011) 054619

  23. •L.G. Moretto, Phys Rev. A247, 221 (1975). • R.J.Charity et al, Nucl.Phys.A483 (1988) • •D.Mancusi et al, PhysRev C 82 (2010) Statistical Model Fermi Gas model (level density) Hauser-Feschbach for LCP’s Trantion state model for IMF Z>2 FRLDM barrier from Sierk Structure effect NOT considered G. Ademard et al. PRC 83 (2011) 054619

  24. G. Ademard et al. PRC 83 (2011) 054619 Dynamical model DNS in competition to CN Quasi-fission phenomena N/Z dependence not considered DSN (di-nuclear system) -model Statistical Model Fermi Gas model (level density) Hauser-Feschbach for LCP’s Trantion state model for IMF Z>2 FRLDM barrier from Sierk Structure effect NOT considered Sh.A.Kalandarov et al. PRC82 (2010) Sh.A.Kalandarov et al. PRC82 (2010)

  25. ISODEC CHIMERA@LNS E= 10 AMeV 78Kr + 40Ca 118 Ba 86Kr + 48Ca 134Ba • Higher energy • Influence on the amplitude of the staggering, on the temperature of the emitting system. • Isotopic separation of IMF • to investigate the staggering effects looking at the isotopic distribution of IMF. • Exploration of a larger domain in N/Z of the system (stable beam!) • to study the dependence from the N/Z on the mechanism of complex fragment emission from CN • Exclusivemeasurements in a large angular range

  26. IMF Isotopic Identification PSD in Silicon ΔE-E , Si-CsI(Tl)

  27. IMF Mass Distribution Li Be B C A=9 A=10 A=7 A=9 Different isotopic compositions and relative enrichment for the same Z in the two systems n-rich 86Kr + 48Ca 10 AMeV, ϑ=12° n-poor 78Kr + 40Ca

  28. Carbon Isotopes Energy Spectra (CM) n-rich Tesi B.Gnoffo 2013

  29. Carbon Isotopes Energy Spectra (CM) n-poor Tesi B.Gnoffo 2013

  30. - Influence of the Isospin (N/Z) • influence of nuclear pairing force • influence of structure effects • (M. D’Agostino et al., NPA 861 (2011) 47 ) • Esym connection (models) Normalized Yields Comparison PRELIMINAR 10.5° ≤ϑ≤ 15.5° New systems with higher N/Z would bring new insights 94Kr + 40,48Ca 10 AMeV132,140 Ba* E* ~ 320 MeV LOI @ SPES- Second SPES Int. Workshop May 2014, LNL Italy

  31. Fragmentation Beams @LNS Chimera group,since 2005, works to test the production of new beams and to realize new experiments @LNS with radioactive beams at intermediate energy.

  32. In-Flight beams@LNS Primary Beam by CS@LNS Stable Nuclei A ~ 10 - 100 E ~ 20 - 60 MeV/A Primary Beam Radiactive &/OR stable nuclei vP Thin target 9Be 500µm- 2500µm vF~ vP RIB @ Intermediate Energy

  33. In-flight fragmentation beams @ LNS CHIMERA Tagging Hodoscope

  34. CHIMERA beam line – tagging system ΔE MCP DSSSD TOF Target

  35. 17C DE (MeV) 16C 13B 12Be 10Be 9Li 6He 7Li T (ns) In-flight fragmentation beams @ LNS Production Tests at the CHIMERA beam line 18O + 9Be (1.5 mm) at 55 MeV/A Primary beam 88W, 5.5x1011 p/s Khz 16C 40 17C 4 13B 23 11Be 6 Setting Bρ=2.71 Tm 10Be 21 8Li 11 E of secondary beam 40-50 MeV/A

  36. ΔE Time 36Ar + 9Be (0.5 mm) 42 MeV/A, primary beam 25W - 1x1011 p/s Khz 37K 14.0 36Ar 12.0 35Ar 8.5 34Ar 1.8 magnetic setting 33Cl 1.5 34Cl 6.5 31S 0.8 32S 10.0 28Si 5.0 29Si 6.5 38Ar 37K 35S 34Ar 31Si 31S 27Si N=Z Energy secondary beams 20-25 MeV/A

  37. 70Zn + 9Be (0.25 mm) 40 MeV/A, primary beam 100W 68Ni Rate 20kHz Energy 28 MeV/A Search for iso-scalar excitation of the PIGMY resonance in 68Ni nuclei G.Cardella, E.G.Lanza for the EXOCHIM coll.

  38. Conclusion & Perspective Recent results were presented in the framework ofDynamics reaction and Isospin Physycsobtained from experiments with stable beams at intermediate and low energies and by using the 4 CHIMERA detector @INFN-LNS. In preparation experiment at the new facility SPES@LNL and with detectors at high specialization, (as the FARCOS correlator). In the meantime, It will be continued the activity of the CHIMERA group by using stable beams and Fragmentation beams @LNS. This will make possible to refine and to improve our knowledge.

  39. EXOCHIM – Collaboration F.Amorini6, L.Auditore7,8, C.Beck9, I.Berceanu10, E.Bonnet5, B.Borderie11, G.Cardella1, A. Chbihi5, M.Colonna6, A.D’Onofrio4,12, J.D.Frankland5, E.Geraci2,1, E.Henry13, E .LaGuidara1,14, G.Lanzalone15,6, P Lautesse16, D.Lebhertz5, N.LeNeindre 17, I.Lombardo4, M.LaCommara3,4, S.Pirrone1, G.Politi1,2, J.P.Wieleczko5, G.Ademard5, E.DeFilippo1, B.Gnoffo2, M.Vigilante3,4, K.Mazurek5, A.Pagano1, M.Papa1, E.Piasecki18, F.Porto2,6, M.Quinlann13, F.Rizzo2,6, E.Rosato3,4, P.Russotto2,6, W.U.Schroeder13, G.Spadaccini3,4, A.Trifirò7,8, J.Toke13, M.Trimarchi7,8, G.Verde1,L. Acosta,, V. Baran, L. Francalanza, S. T. Cap, G. Gianì, L. Grassi, A. Grzeszczuk, P. Guazzoni, J. Han, C. Maiolino, T. Minniti, E.V. Pagano, A. Pop, F. Porto, L.Quattrocchi, J. Wilczyński, L. Zetta. 1) INFN - Catania, Italy 2) Dipartimento di Fisica e Astronomia, Università di Catania, Italy 3) Dipartimento di Scienze Fisiche, Università Federico II Napoli, Italy 4) INFN - Napoli, Italy 5) GANIL - Caen, France 6) INFN LNS - Catania, Italy 7) Dipartimento di Fisica, Università di Messina, Italy 8) INFN Gruppo Collegato di Messina, Italy 9) IN2P3 - IPHC Strasbourg, France 10) IPNE, Bucharest, Romania 11) IN2P3 - IPN Orsay, France 12) Dipartimento di Scienze Ambientali - Seconda Università di Napoli, Caserta, Italy 13) University of Rochester, USA 14) Centro Siciliano Fisica Nucleare e Struttura della Materia, Catania, Italy 15) Università Kore, Enna, Italy 16) IN2P3 - IPN Lyon, France 17) IN2P3 - LPC Caen, France 18) University of Warsaw, Poland

  40. GET: General Electronics for TPC • Especially designed for TPC (gas detectors) to be used with radioactive beams at E/A=5-350 MeV • Integrated and low power consuming • Wide dynamic range (LCP&HI) • Configurable • Digitalization of signals • Might work on photodiodes readout of CsI(Tl) crystals in Chimera and Farcos INFN - Italy , GANIL, CEA-IN2P3, CNRS, IRFU France, Univ. Huelva-Spain

  41. Dynamical Fission: in 124Sn+64Ni and 112Sn+58Ni @35 A.MeV Separation axis Vbeam plane= fission angle on the reaction plane PLF* TLF* Fission axis Reaction plane AP=AH+AL Statistical fission is characterized by isotropic fission fragment angular distribution, Dynamical Fission is characterized by fast AL fragment emission preferentially backwards in the PLF reference system, i.e., towards the target nucleus E. De Filippo et al., Isospin collaboration, Phys. Rev. C71, 064604 (2005)P. Russotto et al., Int. J. Mod. Physics E15 410 (2006) P. Russotto et. al. Phys. Rev. C81, 064605 (2010)

  42. Fission-like fragments angular cross sections (I)  124Sn+64Ni 112Sn+58Ni Forward peaked angular distributions Dynamical Fission Vs Isotropic distributions  Statistical Fission Dynamical Fission cross section is greater in the neutron rich system  (a factor ~2) ! plane=fission angle in the reaction plane P. Russotto et al., PRC 81 064605 (2010)

  43. Activity of the GSS under the chair A.Covello Organization of the First Spes Physics Workshop – LNL Oct. 2008 Formation of the subgroup Instrumentation - 2009 G. Casini, G. de Angelis, G. Pollarolo, G. La Rana Organization of the First SPES Int. Workshop and “Call for Letters of Intent”- LNL Nov. 2010 Organization of the (A.di Pietro-D.Napoli) First Spes School on experimental techniques with radiactive beams - LNS 2011

  44. Organization of the SPES-ONEDAY 2012 -2013 Transfer reactions with RiBs (Napoli, Apr.2012) Coulomb excitations with RIBs (Firenze, Sept 2012) Effects of Isospin in exotic nuclei (Catania, Oct 2013) Collective excitations in exotic nuclei (Milano, Dec 2013) Proposition of the organization of the Second SPES International Workskop – New Call for LOI - LNL May 2014 (realized by GSS with the new chair G.de Angelis)

  45. in flight -vita media breve 100-1000ns (0.1-1 us) • Isol – vita media lunga 0.1 sec (100us)

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