Nuclear Science and Techniques

《核技术》(英文版) ISSN 1001-8042 CN 31-1559/TL     2019 Impact factor 1.556

Nuclear Science and Techniques ›› 2013, Vol. 24 ›› Issue (5): 050516 doi: 10.13538/j.1001-8042/nst.2013.05.016

Special Issue: Special Section on International Workshop on Nuclear Dynamics in Heavy-Ion Reaction (IWND2012)

• Special Section on International Workshop on Nuclear Dynamics in Heavy-Ion Reaction (IWND2012) • Previous Articles     Next Articles

Competition between fusion-evaporation and multifragmentation in central collisions in 58Ni+48Ca at 25A MeV

FRANCALANZA 1,2,*  ABBONDANNO U3  AMORINI F1,2  BARLINI S4  BINI M4  BOUGAULT R5  BRUNO M6  CARDELLA G7  CASINI G8  AGOSTINO M D’6  De FILIPPO V7  De SANCTIS J6  GERACI E2,7  GIUSSANI A9  GRAMEGNA F10  GUIOT B6  KRAVCHUK V10  La GUIDARA E11  LANZALONE G1,12  Le NEINDRE N5  MAIOLINO C1  MARINI P6  MORELLI L6  OLMI APAGANO A7  PAPA M7  PIANTELLI S8  PIRRONE S7  POLITI G2,7  POGGI G4#br# PORTO F1,2  RUSSOTTO P1,2  RIZZO F1,2  VANNINI G6  VANNUCCI L10     

  1. 1INFN Laboratori Nazionali del Sud-LNS, Catania 95123, Italy
    2Dipartimento di Fisica, Università di Catania I-95129, Italy
    3INFN Sezione di Trieste, Trieste I-34127, Italy
    4Dipartimento di Fisica, Università di Firenze, INFN Sezione di Firenze 1-50139, Italy
    5LPC Caen, IN2P3-CNRS/ENSICAEN and Université, F-14050 Caen cedex 5-14076, France
    6Dipartimento di Fisica, Università di Bologna and INFN Sezione di Bologna
    4-50121, Italy
    7INFN Sezione di Catania I-95129, Italy
    8INFN Sezione di Firenze I-50139, Italy
    9Dipartimento di Fisica, Università di Milano and INFN Sezione di Milano1-20126, Italy
    10INFN Laboratori Nazionali di Legnaro 1-35020, Italy
    11Centro Siciliano di Fisica Nucleare e Struttura della Materia, Catania 1-95129, Italy
    12Università Kore, Enna 1-94100, Italy
     
  • Received:2013-06-27
  • Contact: FRANCALANZA L E-mail: laura.francalanza@ct.infn.it
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FRANCALANZA L, ABBONDANNO U, AMORINI F, BARLINI S, BINI M, BOUGAULT R, BRUNO M, CARDELLA G, CASINI G, AGOSTINO M D’, De FILIPPO V, De SANCTIS J, GERACI E, GIUSSANI A, GRAMEGNA F, GUIOT B, KRAVCHUK V, La GUIDARA E, LANZALONE G, Le NEINDRE N, MAIOLINO C, MARINI P, MORELLI L, OLMI A. Competition between fusion-evaporation and multifragmentation in central collisions in 58Ni+48Ca at 25A MeV.Nuclear Science and Techniques, 2013, 24(5): 050516     doi: 10.13538/j.1001-8042/nst.2013.05.016

Abstract:

The experimental data concerning the 58Ni+48Ca reaction at Elab(Ni)=25A MeV, collected by using the CHIMERA 4π device, have been analyzed in order to investigate the competition among different reaction mechanisms for central collisions in the Fermi energy domain. As a main criterion for centrality selection we have chosen the flow angle (?flow) method, making an event-by-event analysis that considers the shape of events, as it is determined by the eigenvectors of the experimental kinetic-energy tensor. For the selected central events (?flow>60°) some global variables, good to characterize the pattern of central collisions have been constructed. The main features of the reaction products were explored by using different constraints on some of the relevant observables, like mass and velocity distributions and their correlations. Much emphasis was devoted, for central collisions,to the competition between fusion-evaporation processes with subsequent identification of a heavy residue and a possible multifragmentation mechanism of a well defined (if any) transient nuclear system. Dynamical evolution of the system and pre-equilibrium emission were taken into account by simulating the reactions in the framework of transport theories. Different approaches have been envisaged (dynamical stochastic BNV calculations + sequential SIMON code, QMD, CoMD, etc.). Preliminary comparison of the experimental data with BNV calculations shows reasonable agreement with the assumption of sequential multifragmentation emission in the mass region of IMFs close to the heavy residues. Possible deviations from sequential processes were found for those IMFs in the region of masses intermediate between the mass of heavy residues and the mass of light IMFs. Further simulations are in progress. The experimental analysis will be enriched also by information obtained inspecting the IMF–IMF correlation function, in order to elucidated the nature of space-time decay property of the emitting source associated with events having the largest IMF multiplicity.

Key words: Heavy ion collisions, Intermediate energy, Flow angle, Fusion-evaporation, Multifragmentation