Physics with CHIMERA at LNS: - PowerPoint Presentation

1. Physics with CHIMERA at LNS: recent results and future perspectivesG.Cardella forthe CHIMERA group

2. OutlineCHIMERA & FARCOS Results with stable beams Radioactive beams New ways to use CHIMERA/FARCOS and on-going upgrades Future perspectives and conclusionsSee also E.De Filippo & A.Pagano EPJA 50(2014)32G.Cardella LNS user meeting 2017

3. STABLE BEAMS / Dynamical FissionQUESTION:is IMF emission statistical or dynamicalANSWER:both processes are present and the sharing between them mainly depends from ISOSPING.Cardella LNS user meeting 2017E. De Filippo et al., PRC 71 064604 (2005)P. Russotto et al., PRC 81, 064605 (2010)P. Russotto et al. PRC 91, 014610 (2015)

4. STABLE BEAMS / Dynamical Fission IMF-IMF correlation in PLF Fission LikeG.Cardella LNS user meeting 2017The correlation function shows extreme sensitivity to the partition of the fission a calibration of this function also using theoretical models is going to better use this information E.V.Pagano PHD ThesisE.V. Pagano IL NUOVO CIM. 39 C (2016) 404E.V. Pagano et al. Proc. Bormio (2017) in preparation;

5. STABLE BEAMS / Isospin dependence of CN decay ISODEC experiment (spokes M.La Commara - G.Politi – S.Pirrone - J.P.Wieleczko)First CHIMERA experiment at low beam energy 78Kr+40Ca & 86Kr+48Ca at 10 AMeVStudy of the dependence of CN formation and decay from the isospin of the system. Pulse Shape on Silicon detector upgrade allowed the Z identification for the stopped particles in silicon. G.Cardella LNS user meeting 2017IMF odd-even staggering effect, more pronounced for the n-poor systemS. Pirrone et al., Journal of Physics: Conf. Series 515 (2014) 012018M.La Commara et al, EPJ Web of Conference 66, 03052 (2014)G. Politi et al., JPS Conf. Proc. Vol. 6 (2015) 030082B. Gnoffo, Nuovo Cimento 39C (2016) 275S.Pirrone, G.politi et al, in preparation

6. STABLE BEAMS / measurement of fusion barrierExperiment on the barrier height distribution of the systems 24Mg + 90,92Zr from 60-90 MeVG.Cardella LNS user meeting 2017Performed measuring the elastic scattering at very backward angles >120° - beautiful results thanks to the complete coverage of the CHIMERA detector at backward angles – The absence of the structure in 92Zr seems confirmed data analysis is in progress Structure already observed with 20Ne beam – very important the confirmation with 24Mg beamE.Piasecki et al., PRC 85,054608 (2012) ; E.Piasecki, A.Trzcincka, M. Wolińska, A.Pagano et al. In preparation

7. STABLE BEAMS / clustering in reaction mechanism Many experiments were done and are still in progress on this argument since the BOSE experiment more recently with SIKO but also with CLIR and a reanalysis of EQUILIBRATION and CORRELATION data G.Cardella LNS user meeting 2017The more recent experiments profits of the energy resolution guaranteed by the new FARCOS telescopes16O + 11B16O + 12CWe can study in detail differences in the correlation functions among the various decay channels available 2a-channelE.V.Pagano et al. (Proc. NN2015 Epj Web of Conf. 117,10008(2016)D.Dell’Aquila et al Nuovo Cim. 39 C (2016) 385

8. STABLE BEAMS / clustering in reaction mechanism Many experiments were done and are still in progress on this argument since the BOSE experiment more recently with SIKO but also with CLIR and a reanalysis of EQUILIBRATION and CORRELATION data G.Cardella LNS user meeting 20177,67 MeV Hoyle state 16O+12C SIKONote the much smaller background under the Hoyle state and 9.7 Mev level populated in the neutron rich system. One has to understand if this is due to reaction mechanism or to the smaller a multiplicity, so smaller incoherent a-decay 48Ca+27Al @ 40 AMeV EQUILIBRATIONJ.Bishop,T.Kokalova et al in preparationM. Papa et al. Phys. Rev. C91, 041601 (2015)

9. 12C+24Mg @ 35AMeVYield of correlated 3α 48Ca+27Al @ 40 AMeVL. Quattrocchi et al. IL NUOVO CIM. 39 C (2016) 391M. Papa et al. PHYS. REV. C91, 041601 (2015) Study of decay mechanisms of produced resonances in 12C: Hoyle stateYield of correlated 3α7,74 MeV Hoyle state7,67 MeV Hoyle stateSTABLE BEAMS / clustering in reaction mechanism From simulationG.Cardella LNS user meeting 2017

10. Hoyle State48Ca+27Al @ 40 AMeVHoyle State12C+24Mg @ 35 AMeVHoyle state produced from breaking of 27Al in rather dissipative collisionsReconstructed parallel velocity of 12C, obtained from the center of mass of 3a detected in coincidence Hoyle state essentially produced from 12C in less dissipative processesSTABLE BEAMS / clustering in reaction mechanism Production mechanism of the Hoyle stateG.Cardella LNS user meeting 2017

11. Radioactive BEAMS / exotic clustering – transfer reactions Note the angular resolution obtained 1-2° in the CM in inverse kinematics notwithstanding the large size of the detectors - due to kinematic rules First observation of a new level of the 10Be with cluster structure a-6HeBetter resolution expected with the new CLIR data in analysisG.Cardella LNS user meeting 2017L.Acosta et al. NIM A 715(2013)56D.Dell’Aquila, I.Lombardo et al PRC 93(2016)0246111

12. Radioactive beams: is CHIMERA only for charged particles?CHIMERA means Charged Heavy Ion Mass and Energy Resolving ArrayHowever we have recently shown that it is not only able to do charged particle detection It is a much more complete detector able to see at the same time g-rays and neutrons G.Cardella LNS user meeting 2017G.C. et al. NIM A 799(2015)64G.C. et al NCC 39 C (2016) 407Auditore L. et al., EPJ Web of Conferences, 88 (2015) 01001

13. CHIMERA – Gamma ray & radioactive beamsG.Cardella LNS user meeting 20171000150010001500DE-channelsE-channelsFirst observation of the excitation and g-decay of the Pygmy resonance in 68Ni with isoscalar excitation using the 68Ni developed at LNS and a 12C target – 68Ni isotopically identified by FARCOS – g-rays detected with the CHIMERA CsI(Tl) of the sphere First measurement of angular distribution of the 68Ni g-decay of the pygmy resonance showing its E1 characterbackgroundPYGMYqcmEnergy g MeVN.Martorana, E.Lanza, G.C et al. in preparation

14. Neutrons signal evaluations (Incidental and direct modes)Some studies have been done on the possible implementation of simultaneous neutron and charged particle detection.L.Auditore,et al. New Tests are going on at LNS-CT-Me (2015-2016) (Data analysis going on )Some tests to compare CSI(Tl) and other materials have been done:Candidate: EJ-299 33Coll. CHIMERA-Rochester group-noise measurements with beamsNext (II-2018):-Neutrons detection in CHIFAR Experiment (E.V.Pagano et al. ) G. Lanzanó,,et al NIM A 312, 3, (1992), Pages 515-520PM -EMI 9954QALike in ARGOS detector PM-Hamamatsu R77220 AMeV C + Al target.P.Russotto et al.CHIMERAFARCOSIn the ShadeEJ-29933 AG.Cardella LNS user meeting 2017

15. On going upgrading – GET electronicsG.Cardella LNS user meeting 2017G.C. et al Il Nuovo Cim. 39 C (2016) 407S.De Luca et al Il Nuovo Cim. 39 C (2016) 411

16. On going upgrading – GET electronicsG.Cardella LNS user meeting 2017GETstandard DAQimproved resolution due to digitalization of the signal allowing the use of filters and the event by event pedestal evaluationG.C. et al Il Nuovo Cim. 39 C (2016) 407S.De Luca et al Il Nuovo Cim. 39 C (2016) 411

17. Forthcoming experimentsG.Cardella LNS user meeting 2017We have some approved experiments to be performed in the second half of 2017 or beginning of 2018 CHIFAR – EQUILIBRATION2 – HOYLE – and more beam time for the PYGMY experiment once some upgrading of the source will be readyCHIFAR on the same theme of previous INKIISSY and ISOSPIN experiments but at lower beam energy 20 AMeV to study the evolution with energy of the isospin dependence of reaction mechanismsEQUILIBRATION2 to continue the study of the dynamics of the Isospin equilibration process through the time derivative of the average total dipole DzHoyle and Pygmy will continue the experience in the measurement of g-rays with CHIMERA – in particular Hoyle will try with an innovative method to study the very small g-decay branching ratio of the Hoyle and of the 9.63 MeV 12C excited states important for astrophysics

18. CONCLUSIONSG.Cardella LNS user meeting 2017There are no conclusions in the work with CHIMERA detector still active after 16 years from the first experiment in the REVERSE configurationThe «standard» CHIMERA measurements are still going using the FARCOS telescopes for a more precise evaluation of correlations also to extract more defined reaction timescalesAlso low energy measurements can be performed allowing detailed data analysis of various processesThe upgrading of the electronics with GET will allow also triggering for CsI detectors enabling more and more accurate measurements also of neutron and g-raysNew groups are welcome to perform beautiful measurement using both stable and radioactive beams ( upgraded in intensity ) with a nearly complete detector6He8He11Li14Be

19. Italian collaboration 2017L.Acosta1,8, L.Auditore4, C.Boiano5, G.Cardella1, A.Castoldi5, M.D’Andrea1, E. De Filippo1,D.Dell’Aquila6, S. De Luca4, F.Fichera1, N.Giudice1, B.Gnoffo1, A.Grimaldi1, C.Guazzoni5, G.Lanzalone2,7, F.Librizzi1, I.Lombardo6, C.Maiolino2, S.Maffesanti5, N.Martorana2, S.Norella4, A.Pagano1, E.V.Pagano2,3, M.Papa1, T.Parsani5, G.Passaro2, S.Pirrone1, G.Politi1,3, F.Previdi5, L.Quattrocchi4, F.Rizzo2,3, P.Russotto2, G.Saccà1, G.Salemi1, D.Sciliberto1, A.Trifirò4, M.Trimarchì4, M.Vigilante61-INFN Sezione di Catania2-INFN LNS3-Dipartimento di Fisica e Astronomia Università di Catania4-INFN_gr. Coll. Messina and Dipartimento di Fisica Università Messina5-INFN- Sezione di Milano and Politecnico di Milano6-INFN-Sez. di Napoli and Dipartimento di Fisica Università di Napoli Federico II7-Università Kore Enna8-Instituto de Física Universidad Nacional Autónoma de México Apartado Postal 20-364, México D. F. 01000G.Cardella LNS user meeting 2017