for NEWCHIM-ISODEC Collaboration International Workshop  Nuclear Reactions on Nucleons and Nuclei  Messina (Italy) - October 25-26, 2017 Isospin influence on the reaction mechanisms in the78Kr+40Ca and 86Kr+48Ca collisions at 10 AMeV Brunilde Gnoffo for NEWCHIM-ISODEC Collaboration Istituto Nazionale di Fisica Nucleare - Sezione di Catania Università degli Studi di Catania

Heavy-ion induced reactions with stable and radioactive beams are ideal to explore the nuclei under different stress conditions. The isospin influence is expected to play a crucial role in the reaction dynamics Low energy regime E < 15 MeV/A is dominated by Compound Nucleus formation and de-excitations in competition with binary processes (DIC, Quasi-Fission) N/Z ratio, connected to the isospin degree of freedom, influences: Fragments formation Reaction mechanisms Competition among the different decay channels of the Compound Nucleus Physics Case

78Kr + 40Ca -> 118Ba* 86Kr + 48Ca -> 134Ba* Experimental method @E/A=10 MeV/A 118Ba 134Ba E*(MeV) 215 270 (N/Z)tot 1.11 1.39 S. Pirrone et al., Journal of Physics: Conf. Series 515 (2014) 012018 G. Politi et al., JPS Conf. Proc. Vol. 6 (2015) 030082 B. G. Il Nuovo Cimento C39 (2016) 275 CHIMERA at INFN-LNS A. Pagano et al., NPA681 (2001)331

78Kr + 40Ca -> 118Ba* 86Kr + 48Ca -> 134Ba* Experimental method @E/A=10 MeV/A 118Ba 134Ba E*(MeV) 215 270 (N/Z)tot 1.11 1.39 S. Pirrone et al., Journal of Physics: Conf. Series 515 (2014) 012018 G. Politi et al., JPS Conf. Proc. Vol. 6 (2015) 030082 B. G. Il Nuovo Cimento C39 (2016) 275 78,82Kr + 40Ca -> 118,122Ba* @ E/A=5.5 MeV/A E* ≈ 100 MeV INDRA at GANIL G. Ademard et al. PRC 83 (2011) 054619 Composite systems with higher E -> effects on decay Larger domain of N/Z (max with stable beam) CHIMERA at INFN-LNS A. Pagano et al., NPA681 (2001)331

Experimental results TKE reconstructed from fragment kinematical characteristics in inclusive analysis

Experimental results TKE reconstructed from fragment kinematical characteristics in inclusive analysis Dynamical mechanism with TKE > 150 MeV and small ϑcm

Experimental results TKE reconstructed from fragment kinematical characteristics in inclusive analysis Dynamical mechanism with TKE > 150 MeV and small ϑcm Relaxed process with TKE ~ 85 MeV for any angle Value in agreement with a compilation of C. Beck and S. de Toledo on fission energy release C.Beck and A. S. de Toledo, Phys. Rev. C 53, 1989 (1996) Analogue results for n-rich system, with DIC even more present

Mtot - Ptot plot for complete events selection: Experimental results Mtot - Ptot plot for complete events selection: 0.8*ACN ≤ Atot ≤ 1.1*ACN 0.6 ≤ ptot/pbeam ≤1.1

Experimental results TKE measured in complete events condition Relaxed process with TKE ~ 85 MeV for any angle Value in agreement with the values obtained in the calculation for the inclusive analysis TKE measured in complete events condition TKE calculated in inclusive analysis

Further information from Complete Events Experimental results Further information from Complete Events Correlation between fragment mass and parallel velocity Fission-Like processes are enhanced in the n-poor system Mostly Binary decay is presents in both systems -> Important information on the interplay between mechanism

Further information from Complete Events Experimental results Further information from Complete Events Correlation between fragment mass and parallel velocity Fission-Like processes are enhanced in the n-poor system Mostly Binary decay is presents in both systems -> Important information on the interplay between mechanism Evaporation Fission Like

Experimental results Average velocity for Z= 3-38 in the c.m. frame for different Z and at different θlab -> Energy and velocity spectra in c.o.m frame pratically independent of the emission angles and decresing with Z -> Good agreement with Viola-Hinde systematic -> Regular behavior slightly disregarded for Z>30, maybe due to the dynamic mechanism contribution

Experimental results Angular distributions in the center of mass frame for Z from 10 up to 38 1/sinθ behaviour -> high degree of relaxation, long lived system

Experimental results Angular distributions in the center of mass frame for Z from 10 up to 38 1/sinθ behaviour -> high degree of relaxation, long lived system Z>28 ->Stronger contribution at smaller angles->not fully equilibrated binary mechanism

Experimental results Charge Distributions -> Fragments production globally favored for n-poor ->Strong even-odd effect , staggering, more pronounced for the n-poor system ->Charge distribution asymmetric with respect to ZCN/2=28-> process not fully relaxed in mass

Experimental results Selection of complete events to get rid of very dissipative binary collisions (TLF not detected) 78Kr + 40Ca 86Kr + 48Ca inclusive inclusive Complete events Complete events Cross sections normalized to value for Z = 18 The dynamic process seems to influence fragment production starting From Z > 28 - 30

Experimental results Reaction Cross sections - Fusion Evaporation - ER: Z > 41 and by subtracting FL for heavier fragments - Fission Like - FL: Z = 3 - 28/26 -> not affected by DIC - Reaction: elastic scattering (quarter point recipe)   σER(mb) σFL(mb) σFus(mb) qp  σReac (mb) 78Kr+40Ca 455±70 850±120 1305±190 2390±250 86Kr+48Ca 400±60 530±85 930±145 2520±260

Experimental results Reaction Cross sections - Fusion Evaporation - ER: Z > 41 and by subtracting FL for heavier fragments - Fission Like - FL: Z = 3 - 28/26 -> not affected by DIC - Reaction: elastic scattering (quarter point recipe)   σER(mb) σFL(mb) σFus(mb) qp  σReac (mb) 78Kr+40Ca 455±70 850±120 1305±190 2390±250 86Kr+48Ca 400±60 530±85 930±145 2520±260 -> Fusion Evaporation similar in the two systems -> Fission Like more present for n-poor systems -> Difference sReac - sFus probably due to the DIC, more pronounced for the n-rich system

Comparison with GEMINI++ code Experimental results Comparison with GEMINI++ code

Comparison with Dinuclear System code Experimental results Comparison with Dinuclear System code Sh.A.Kalandarov et al., PRC 93 (2016) 024613

Correlation between sizes of the two biggest fragments Experimental results Correlation between sizes of the two biggest fragments ER FF QF 78Kr +40Ca M1 5.5 AMeV 10 AMeV M2 G. Ademard et al., PRC 83 (2011) 054619 Present work

Experimental results Correlation between sizes of the two biggest fragments IMF production is more pronounced at high energy ER FF QF 78Kr +40Ca M1 5.5 AMeV 10 AMeV M2 Fission Like Evaporation G. Ademard et al., PRC 83 (2011) 054619 Present work

Comparison of FF production cross sections in the reaction Experimental results Comparison of FF production cross sections in the reaction 78Kr +40Ca at two different energies In agreement with : J. Boger et al., PRC 49 (1994) 1597

Preliminary study of ternary events Correlation of FF and alpha emitted Experimental results

Preliminary results of α-particle vpar-vper in the fragment’s frame Experimental results Preliminary results of α-particle vpar-vper in the fragment’s frame 78Kr + 40Ca @ 10 AMeV Present work Vpar(cm/ns) Vper (cm/ns) PRELIMINARY Z=6 frame Compl Z=6 frame Z=14 frame Compl Z=14 frame Z=26 frame Compl Z=26 frame

Preliminary results of α-particle vpar-vper in the fragment’s frame Experimental results Preliminary results of α-particle vpar-vper in the fragment’s frame 78Kr + 40Ca @ 10 AMeV 78Kr + 40Ca @ 5.5 AMeV Present work Vpar(cm/ns) Vper (cm/ns) PRELIMINARY G. Ademard et al., PRC 83 (2011) 054619 Z=6 frame Compl Z=6 frame Z=14 frame Compl Z=14 frame Z=26 frame Compl Z=26 frame

Experimental results Preliminary results of α-particle vpar-vper in the light fragment’s frame 78Kr + 40Ca PRELIMINARY Vper(cm/ns) 86Kr + 48Ca Vpar (cm/ns)

Conclusion and Outlook Results of inclusive and complete events analysis of the reactions 78,86Kr + 40,48Ca at 10 AMeV are presented N/Z ratio influences the competition among the different reaction channels: DIC, FF, QF and ER Conclusion and Outlook

Conclusion and Outlook Results of inclusive and complete events analysis of the reactions 78,86Kr + 40,48Ca at 10 AMeV are presented N/Z ratio influences the competition among the different reaction channels: DIC, FF, QF and ER Kinematical characteristics typical of an energy equilibrated system Conclusion and Outlook

Conclusion and Outlook Staggering in cross sections DIC effects Z>28-30 Conclusion and Outlook

Conclusion and Outlook Staggering in cross sections DIC effects Z>28-30 Evaporation comparable but Fission more present for n-poor Conclusion and Outlook

Conclusion and Outlook Stronger IMF production at high energy for the n-poor System Conclusion and Outlook

Conclusion and Outlook Stronger IMF production at high energy for the n-poor System Stronger α emission in symmetric fission respect to very asymmetric and asymmetric fission-> for the n-rich system Conclusion and Outlook

Conclusion and Outlook Further analysis to be done: - Study of three fragments events and in particular Projectile like Fragment fission - Analysis of Deep Inelastic Contribution as a function of N/Z - Analysis of LCP in coincidence with ER and FF Conclusion and Outlook

92Kr + 40,48Ca 10 AMeV 132,140Ba* E* ~ 320 MeV (N/Z)CN =1.5 Conclusion and Outlook LOI @SPES ( E. De Filippo, J. Frankland, S. Pirrone, G. Politi, P. Russotto) (approved by the Scientific Advisory Committee at LNL) 92Kr + 40,48Ca 10 AMeV 132,140Ba* E* ~ 320 MeV (N/Z)CN =1.5 -> investigation of the evolution of the dynamics with isospin asymmetry -> interplay between nuclear structure and reaction mechanism in the emission process

NEWCHIM – ISODEC collaboration B. Gnoffo1,2, S. Pirrone1, G. Politi1,2, J.P. Wieleczko3, E. De Filippo1, P. Russotto1,2, M. Trimarchi1,4, M. Vigilante5,6, G. Ademard7, L. Auditore1,4, C. Beck8, I. Berceanu9, E. Bonnet3, B. Borderie7, G. Cardella1, A. Chibihi3, M. Colonna10, D. Dell’ Aquila5,6, J. D. Frankland3, E. Geraci1, M. La Commara5,6, G. Lanzalone11, P. Lautesse12, D. Lebhertz3, N. Le Neindre13, N.S. Martorana1,10, K. Mazurek3, A. Pagano1, E.V. Pagano2,10, M. Papa1, E. Piasecki14, F. Porto10, L. Quattrocchi1,2, F. Rizzo1,10, G. Spadaccini5,6, A. Trifirò1,4 and G. Verde1,7. 1 INFN Sezione di Catania, Italy 2 Dipartimento di Fisica e Astronomia, Università di Catania, Italy 3 GANIL Caen,France 4 Dipartimento di Fisica, Università di Messina, Italy 5 Dipartimento di Fisica, Università Federico II Napoli, Italy 6 INFN Sezione di Napoli, Italy 7 IN2P3 - IPN Orsay, France 8 IN2P3 - IPHC Strasbourg, France 9 IPNE, Bucharest, Romania 10 INFN Laboratori Nazionali del Sud, Italy 11Università Kore, Enna, Italy 12 IN2P3 - IPN Lyon, France 13 IN2P3 - LPC Caen, France 14 University of Warsaw, Poland