1. Physics with CHIMERA at LNS: recent results and future perspectives
G.Cardella
for
the CHIMERA group

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

3. STABLE BEAMS / Dynamical Fission
QUESTION:
is IMF emission statistical or dynamical
ANSWER:
both processes are present and the sharing between them mainly depends from ISOSPIN
E. De Filippo et al., PRC (2005)
P. Russotto et al., PRC 81, (2010)
P. Russotto et al. PRC 91, (2015)
G.Cardella LNS user meeting 2017

4. STABLE BEAMS / Dynamical Fission
IMF-IMF correlation in PLF Fission Like
The 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 Thesis
E.V. Pagano IL NUOVO CIM. 39 C (2016) 404
E.V. Pagano et al. Proc. Bormio (2017) in preparation;
G.Cardella LNS user meeting 2017

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 AMeV
Study 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.
S. Pirrone et al., Journal of Physics: Conf. Series 515 (2014)
M.La Commara et al, EPJ Web of Conference 66, (2014)
G. Politi et al., JPS Conf. Proc. Vol. 6 (2015)
B. Gnoffo, Nuovo Cimento 39C (2016) 275
S.Pirrone, G.politi et al, in preparation
IMF odd-even staggering effect, more pronounced for the n-poor system
G.Cardella LNS user meeting 2017

6. STABLE BEAMS / measurement of fusion barrier
Experiment on the barrier height distribution of the systems 24Mg + 90,92Zr from MeV
Performed 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 beam
E.Piasecki et al., PRC 85, (2012) ;
E.Piasecki, A.Trzcincka, M. Wolińska, A.Pagano et al. In preparation
G.Cardella LNS user meeting 2017

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
The more recent experiments profits of the energy resolution guaranteed by the new FARCOS telescopes
16O + 11B
16O + 12C
2a-channel
We can study in detail differences in the correlation functions among the various decay channels available
E.V.Pagano et al. (Proc. NN2015 Epj Web of Conf. 117,10008(2016)
D.Dell’Aquila et al Nuovo Cim. 39 C (2016) 385
G.Cardella LNS user meeting 2017

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
16O+12C SIKO
40 AMeV EQUILIBRATION
7,67 MeV
Hoyle state
Note 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
J.Bishop,T.Kokalova et al in preparation
M. Papa et al. Phys. Rev. C91, (2015)
G.Cardella LNS user meeting 2017

9. STABLE BEAMS / clustering in reaction mechanism
Study of decay mechanisms of produced resonances in 12C: Hoyle state
35AMeV
40 AMeV
From simulation
Yield of correlated 3α
7,67 MeV
Hoyle state
Yield of correlated 3α
7,74 MeV
Hoyle state
L. Quattrocchi et al. IL NUOVO CIM. 39 C (2016) 391
M. Papa et al. PHYS. REV. C91, (2015)
G.Cardella LNS user meeting 2017

10. STABLE BEAMS / clustering in reaction mechanism
Production mechanism of the Hoyle state
Hoyle State
40 AMeV
Hoyle state produced from breaking of 27Al in rather dissipative collisions
Reconstructed parallel velocity of 12C, obtained from the center of mass of 3a detected in coincidence
Hoyle State
35 AMeV
Hoyle state essentially produced from 12C in less dissipative processes
G.Cardella LNS user meeting 2017

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

12. Radioactive beams: is CHIMERA only for charged particles?
CHIMERA means Charged Heavy Ion Mass and Energy Resolving Array
However 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.C. et al. NIM A 799(2015)64
G.C. et al NCC 39 C (2016) 407
Auditore L. et al., EPJ Web of Conferences, 88 (2015) 01001
G.Cardella LNS user meeting 2017

13. CHIMERA – Gamma ray & radioactive beams
1000
1500
DE-channels
E-channels
First 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
background
PYGMY
First measurement of angular distribution of the 68Ni g-decay of the pygmy resonance showing its E1 character
Energy g MeV
qcm
N.Martorana, E.Lanza, G.C et al. in preparation
G.Cardella LNS user meeting 2017

14. Some tests to compare CSI(Tl) and other materials have been done:
Neutrons signal evaluations (Incidental and direct modes)
Some studies have been done on the possible implementation of simultaneous neutron and charged particle detection.
P.Russotto et al.
Some tests to compare CSI(Tl) and other materials have been done:
Candidate: EJ
Coll. CHIMERA-Rochester group
In the Shade
FARCOS
CHIMERA
20 AMeV C + Al target.
L.Auditore,et al.
PM-Hamamatsu R772
New Tests are going on at LNS-CT-Me ( ) (Data analysis going on )
PM -EMI 9954QA
Like in ARGOS detector
EJ A
-noise measurements with beams
Next (II-2018):
-Neutrons detection in CHIFAR Experiment (E.V.Pagano et al. )
G. Lanzanó,,et al NIM A 312, 3, (1992), Pages
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15. On going upgrading – GET electronics
G.C. et al Il Nuovo Cim. 39 C (2016) 407
S.De Luca et al Il Nuovo Cim. 39 C (2016) 411
G.Cardella LNS user meeting 2017

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

17. time derivative of the average total dipole Dz
Forthcoming experiments
We 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 ready
CHIFAR 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 mechanisms
EQUILIBRATION2 to continue the study of the dynamics of the Isospin equilibration process through the
time derivative of the average total dipole Dz
Hoyle 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
G.Cardella LNS user meeting 2017

18. CONCLUSIONS
There are no conclusions in the work with CHIMERA detector still active after 16 years from the first experiment in the REVERSE configuration
The «standard» CHIMERA measurements are still going using the FARCOS telescopes for a more precise evaluation of correlations also to extract more defined reaction timescales
Also low energy measurements can be performed allowing detailed data analysis of various processes
The upgrading of the electronics with GET will allow also triggering for CsI detectors enabling more and more accurate measurements also of neutron and g-rays
6He
8He
11Li
14Be
New groups are welcome to perform beautiful measurement using both stable and radioactive beams ( upgraded in intensity ) with a nearly complete detector
G.Cardella LNS user meeting 2017

19. Italian collaboration 2017
L.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.Vigilante6
1-INFN Sezione di Catania
2-INFN LNS
3-Dipartimento di Fisica e Astronomia Università di Catania
4-INFN_gr. Coll. Messina and Dipartimento di Fisica Università Messina
5-INFN- Sezione di Milano and Politecnico di Milano
6-INFN-Sez. di Napoli and Dipartimento di Fisica Università di Napoli Federico II
7-Università Kore Enna
8-Instituto de Física Universidad Nacional Autónoma de México Apartado Postal , México D. F
G.Cardella LNS user meeting 2017