# Nuclear physics midterm plan at LNS

C Agodi, F Cappuzzello, G Cardella, G.A.P Cirrone, E de Filippo, A Di Pietro, A Gargano, M La Cognata, D Mascali, G Milluzzo, et al.

<figure><img src="image_1.png" /></figure>

## ► To cite this version:

C Agodi, F Cappuzzello, G Cardella, G.A.P Cirrone, E de Filippo, et al., Nuclear physics midterm plan at LNS. The European Physical Journal Plus, 2023, 138 (11), pp.1038. 10.1140/epjp/s13360-023-04358-7. [hal-04311737](https://hal.science/hal-04311737)

HAL Id: hal-04311737

https://hal.science/hal-04311737

Submitted on 27 May 2024

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<figure><img src="image_2.png" /></figure>
Nuclear physics midterm plan at LNS

C Agodi, F Cappuzzello, G Cardella, G.A.P Cirrone, E de Filippo, A Di Pietro, A Gargano, M La Cognata, D Mascali, G Milluzzo, et al.

<figure><img src="image_1.png" /></figure>

To cite this version:

C Agodi, F Cappuzzello, G Cardella, G.A.P Cirrone, E de Filippo, et al. Nuclear physics midterm plan at LNS. The European Physical Journal Plus, 2023, 138 (11), pp.1038. 10.1140/epjp/s13360-023-04358-7. hal-04311737

HAL Id: hal-04311737

https://hal.science/hal-04311737v1

Submitted on 27 May 2024

**HAL** is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_2.png" /></figure>
Nuclear physics midterm plan at LNS

C. Agodi<fnref n="1" />, F. Cappuzzello<fnref n="1" />,<fnref n="2" />, G. Cardella<fnref n="3" />, G. A. P. Cirrone<fnref n="1" />, E. De Filippo<fnref n="3" />, A. Di Pietro<fnref n="1" />, A. Gargano<fnref n="4" />,
M. La Cognata<fnref n="1" />,<fnref n="4" />, D. Mascali<fnref n="1" />, G. Milluzzo<fnref n="1" />, R. Nania<fnref n="5" />, G. Petringa<fnref n="1" />, A. Pidatella<fnref n="1" />, S. Pirrone<fnref n="3" />, R. G. Pizzone<fnref n="1" />,
G. G. Rapisarda<fnref n="1" />,<fnref n="2" />,<fnref n="6" />, M. L. Sergi<fnref n="1" />,<fnref n="2" />, S. Tudisco<fnref n="1" />, J. J. Valiente-Dobón<fnref n="7" />, E. Vardaci<fnref n="4" />,<fnref n="8" />, H. Abramczyk<fnref n="9" />, L. Acosta<fnref n="10" />,
P. Adsley<fnref n="11" />, S. Amaducci<fnref n="1" />, T. Banerjee<fnref n="4" />, D. Batani<fnref n="12" />, J. Bellone<fnref n="1" />,<fnref n="2" />, C. Bertulani<fnref n="11" />,<fnref n="13" />, S. Biri<fnref n="14" />, A. Bogachev<fnref n="15" />,
A. Bonanno<fnref n="1" />,<fnref n="16" />, A. Bonasera<fnref n="1" />,<fnref n="11" />, C. Borcea<fnref n="17" />, M. Borghesi<fnref n="18" />, S. Bortolussi<fnref n="19" />,<fnref n="20" />, D. Boscolo<fnref n="14" />, G. A. Brischetto<fnref n="1" />,<fnref n="2" />,
S. Burrello<fnref n="1" />,<fnref n="2" />,<fnref n="22" />, M. Busso<fnref n="23" />,<fnref n="24" />, S. Calabrese<fnref n="1" />, S. Calinescu<fnref n="17" />, D. Calvo<fnref n="25" />, V. Capirossi<fnref n="25" />,<fnref n="26" />, D. Carbone<fnref n="1" />, A. Cardinali<fnref n="27" />,
G. Casini<fnref n="28" />, R. Catalano<fnref n="1" />, M. Cavallaro<fnref n="1" />, S. Ceccuzzi<fnref n="29" />, L. Celona<fnref n="1" />, S. Cherubini<fnref n="1" />,<fnref n="2" />, A. Chieffi<fnref n="24" />,³⁰, I. Ciraldo<fnref n="1" />,<fnref n="2" />,
G. Ciullo³¹,³², M. Colonna<fnref n="1" />, L. Cosentino<fnref n="1" />, G. Cuttone<fnref n="1" />, G. D'Agata<fnref n="1" />,<fnref n="2" />, G. De Gregorio<fnref n="4" />,³³, S. Degl'Innocenti³⁴,
F. Delaunay<fnref n="1" />,<fnref n="2" />,³⁵, L. Di Donato<fnref n="1" />,³⁶, A. Di Nitto<fnref n="4" />,<fnref n="8" />, T. Dickel³⁷,³⁸, D. Doria<fnref n="17" />,³⁹, J. E. Ducret⁴⁰, M. Durante<fnref n="14" />, J. Esposito<fnref n="7" />,
F. Farrokhi<fnref n="1" />, J. P. Fernandez Garcia<fnref n="21" />, P. Figuera<fnref n="1" />, M. Fisichella<fnref n="1" />, Z. Fulop<fnref n="14" />, A. Galatá<fnref n="6" />, D. Galaviz Redondo⁴¹,
D. Gambacurta<fnref n="1" />, S. Gammino<fnref n="1" />, E. Geraci<fnref n="2" />,<fnref n="3" />, L. Gizzi⁴², B. Gnoffo<fnref n="2" />,<fnref n="3" />, F. Groppi<fnref n="26" />,<fnref n="27" />, G. L. Guardo<fnref n="1" />, M. Guarrera<fnref n="1" />,
S. Hayakawa⁴³, F. Horst<fnref n="14" />, S. Q. Hou⁴⁴, A. Jarota<fnref n="8" />, J. José⁴⁵, S. Kar<fnref n="18" />,⁴⁶, A. Karpov<fnref n="15" />, H. Kierzkowska-Pawlak<fnref n="9" />,
G. G. Kiss<fnref n="14" />, G. Knyazheva<fnref n="15" />, H. Koivisto⁴⁷, B. Koop⁷², E. Kozulin<fnref n="14" />, D. Kumar³⁷,³⁸, A. Kurmanova<fnref n="1" />, G. La Rana<fnref n="4" />,<fnref n="8" />,
L. Labate⁴², L. Lamia<fnref n="1" />,<fnref n="2" />, E. G. Lanza<fnref n="3" />, J. A. Lay⁴⁸,⁴⁹, D. Lattuada<fnref n="1" />,<fnref n="6" />, H. Lenske⁵⁰, M. Limongi<fnref n="24" />,³⁰,⁵¹, M. Lipoglavsek⁵²,
I. Lombardo<fnref n="2" />,<fnref n="3" />, A. Mairani⁷², S. Manetti<fnref n="26" />,<fnref n="27" />, M. Marafini⁷¹, L. Marcucci³⁴, D. Margarone⁵³, N. S. Martorana<fnref n="1" />,<fnref n="3" />,
L. Maunoury⁴⁰, G. S. Mauro<fnref n="1" />, M. Mazzaglia<fnref n="1" />, S. Mein⁷², A. Mengoni<fnref n="5" />,⁵⁴, M. Milin⁵⁵, B. Mishra<fnref n="1" />, L. Mou<fnref n="7" />, J. Mrazek⁵⁶,
P. Nadtochy⁵⁷, E. Naselli<fnref n="1" />, P. Nicolai<fnref n="12" />, K. Novikov<fnref n="15" />, A. A. Oliva<fnref n="1" />, A. Pagano<fnref n="3" />, E. V. Pagano<fnref n="1" />, S. Palmerini<fnref n="23" />,<fnref n="24" />, M. Papa<fnref n="3" />,
K. Parodi⁷³, V. Patera⁵⁸, J. Pellumaj<fnref n="7" />,³¹, C. Petrone<fnref n="24" />, S. Piantelli<fnref n="28" />, D. Pierroutsakou<fnref n="4" />, F. Pinna<fnref n="25" />, G. Politi<fnref n="2" />,<fnref n="3" />,
I. Postuma<fnref n="19" />,<fnref n="20" />, P. Prajapati<fnref n="1" />,⁵⁹, P. G. Prada Moroni³⁵, G. Pupillo<fnref n="7" />, D. Raffestin<fnref n="12" />, R. Racz<fnref n="14" />, C.-A. Reidel<fnref n="14" />,
D. Rifuggiato<fnref n="1" />, F. Risitano<fnref n="3" />,⁶⁰, F. Rizzo<fnref n="2" />,<fnref n="3" />, X. Roca Maza⁶¹,⁶², S. Romano<fnref n="1" />,<fnref n="2" />, L. Roso⁶³, F. Rotaru<fnref n="17" />, A. D. Russo<fnref n="1" />,
P. Russotto<fnref n="1" />, V. Saiko<fnref n="15" />, D. Santonocito<fnref n="1" />, E. Santopinto⁶⁴, G. Sarri⁴⁶, D. Sartirana<fnref n="25" />, C. Schuy<fnref n="14" />, O. Sgouros<fnref n="1" />,
S. Simonucci⁶⁵, G. Sorbello<fnref n="1" />,³⁶, V. Soukeras<fnref n="1" />, R. Spartá<fnref n="1" />, A. Spatafora<fnref n="1" />,<fnref n="2" />, M. Stanoiu<fnref n="17" />, S. Taioli⁶⁶,⁶⁷,⁶⁸, T. Tessonnier⁷²,
P. Thirolf⁷³, E. Tognelli³⁴, D. Torresi<fnref n="1" />, G. Torrisi<fnref n="1" />, L. Trache<fnref n="17" />, G. Traini⁷⁰, M. Trimarchi<fnref n="3" />,⁶⁰, S. Tsikata⁶⁹, A. Tumino<fnref n="1" />,<fnref n="6" />,
J. Tyczkowski<fnref n="9" />, H. Yamaguchi⁴³, V. Vercesi<fnref n="19" />,<fnref n="20" />, I. Vidana<fnref n="3" />, L. Volpe⁶³, U. Weber<fnref n="14" />

<footnote n="1">¹ Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, 95123 Catania, Italy</footnote>

<footnote n="2">² Dipartimento di Fisica e Astronomia “Ettore Majorana”, University of Catania, 95123 Catania, Italy</footnote>

<footnote n="3">³ Sezione di Catania, Istituto Nazionale di Fisica Nucleare, 95123 Catania, Italy</footnote>

<footnote n="4">⁴ Sezione di Napoli, Istituto Nazionale di Fisica Nucleare, 80126 Napoli, Italy</footnote>

<footnote n="5">⁵ Sezione di Bologna, Istituto Nazionale di Fisica Nucleare, 40127 Bologna, Italy</footnote>

<footnote n="6">⁶ Facoltà di Ingegneria e Architettura, Università degli Studi di Enna “Kore”, 94100 Enna, Italy</footnote>

<footnote n="7">⁷ Laboratori Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare, 35020 Legnaro, Italy</footnote>

<footnote n="8">⁸ Dipartimento di Fisica “Ettore Pancini”, Università di Napoli Federico II, 80126 Napoli, Italy</footnote>

<footnote n="9">⁹ Department of Molecular Engineering, Faculty of Process and Environmental Engineering, Lodz University of Technology, 93-005 Lodz, Poland</footnote>

<footnote n="10">¹⁰ Instituto de Fisica, Universidad Nacional Autonoma de Mexico, 04510 Mexico City, Mexico</footnote>

<footnote n="11">¹¹ Cyclotron Institute, Texas A&M University, College Station, TX 77840, USA</footnote>

<footnote n="12">¹² Centre Lasers Intenses et Applications (CELIA), University of Bordeaux, 33400 Talence, Bordeaux, France</footnote>

<footnote n="13">¹³ Department of Physics and Astronomy, Texas A&M University-Commerce, Commerce, TX 75429-3011, USA</footnote>

<footnote n="14">¹⁴ Atomki, Institute of Nuclear Research, 4026 Debrecen, Hungary</footnote>

<footnote n="15">¹⁵ Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, Dubna, Russia 141980</footnote>

<footnote n="16">¹⁶ Osservatorio Astrofisico di Catania, INAF, via S.Sofia 78, 95123 Catania, Italy</footnote>

<footnote n="17">¹⁷ IFIN-HH “Horia Hulubei”, National Institute of Physics and Nuclear Engineering, 077125 Magurele, Romania</footnote>

<footnote n="18">¹⁸ School of Mathematics and Physics, Centre for Plasma Physics, Queen’s University, Belfast, Northern Ireland BT7 1NN, UK</footnote>

<footnote n="19">¹⁹ Dipartimento di Fisica, Università degli Studi di Pavia, Via Agostino Bassi, 6, 27100 Pavia, Italy</footnote>

<footnote n="20">²⁰ Sezione di Pavia, Istituto Nazionale di Fisica Nucleare (INFN), Via Agostino Bassi, 6, 27100 Pavia, Italy</footnote>

<footnote n="21">²¹ Departamento de Física Atómica Molecular y Nuclear, University of Seville, 41012 Sevilla, Spain</footnote>

<footnote n="22">²² Fachbereich Physik, Institut für Kernphysik, Technische Universität Darmstadt, 61010 Darmstadt, Germany</footnote>

<footnote n="23">²³ Dipartimento di Fisica e Geologia, Università di Perugia, 06125 Perugia, Italy</footnote>

<footnote n="24">²⁴ Sezione di Perugia, Istituto Nazionale di Fisica Nucleare, 06125 Perugia, Italy</footnote>

<footnote n="25">²⁵ Sezione di Torino, Istituto Nazionale di Fisica Nucleare, 10125 Torino, Italy</footnote>

<footnote n="26">²⁶ DISAT, Politecnico di Torino, 10129 Torino, Italy</footnote>

<footnote n="27">²⁷ FSN Department, ENEA, DTT S.C.a r.l., 00044 Frascati, Italy</footnote>

<footnote n="28">²⁸ Sezione di Firenze, Istituto Nazionale di Fisica Nucleare, 50019 Sesto Fiorentino (Fi), Italy</footnote>

<footnote n="29">²⁹ ENEA, DTT S.C.a r.l., 00044 Frascati, Italy</footnote>

<footnote>ᵃ e-mail: lacognata@lns.infn.it</footnote>

<footnote>ᵇ e-mail: grapisarda@lns.infn.it (corresponding author)</footnote>
Nuclear physics midterm plan at LNS

C. Agodi<fnref n="1" />, F. Cappuzzello<fnref n="1" />,<fnref n="2" />, G. Cardella<fnref n="3" />, G. A. P. Cirrone<fnref n="1" />, E. De Filippo<fnref n="3" />, A. Di Pietro<fnref n="1" />, A. Gargano<fnref n="4" />,
M. La Cognata<fnref n="1" />,<fnref n="4" />, D. Mascali<fnref n="1" />, G. Milluzzo<fnref n="1" />, R. Nania<fnref n="5" />, G. Petringa<fnref n="1" />, A. Pidatella<fnref n="1" />, S. Pirrone<fnref n="3" />, R. G. Pizzone<fnref n="1" />,
G. G. Rapisarda<fnref n="1" />,<fnref n="2" />,<fnref n="6" />, M. L. Sergi<fnref n="1" />,<fnref n="2" />, S. Tudisco<fnref n="1" />, J. J. Valiente-Dobón<fnref n="7" />, E. Vardaci<fnref n="4" />,<fnref n="8" />, H. Abramczyk<fnref n="9" />, L. Acosta<fnref n="10" />,
P. Adsley<fnref n="11" />, S. Amaducci<fnref n="1" />, T. Banerjee<fnref n="4" />, D. Batani<fnref n="12" />, J. Bellone<fnref n="1" />,<fnref n="2" />, C. Bertulani<fnref n="11" />,<fnref n="13" />, S. Biri<fnref n="14" />, A. Bogachev<fnref n="15" />,
A. Bonanno<fnref n="1" />,<fnref n="16" />, A. Bonasera<fnref n="1" />,<fnref n="11" />, C. Borcea<fnref n="17" />, M. Borghesi<fnref n="18" />, S. Bortolussi<fnref n="19" />,<fnref n="20" />, D. Boscolo<fnref n="14" />, G. A. Brischetto<fnref n="1" />,<fnref n="2" />,
S. Burrello<fnref n="1" />,<fnref n="2" />,<fnref n="22" />, M. Busso<fnref n="23" />,<fnref n="24" />, S. Calabrese<fnref n="1" />, S. Calinescu<fnref n="17" />, D. Calvo<fnref n="25" />, V. Capirossi<fnref n="25" />,<fnref n="26" />, D. Carbone<fnref n="1" />, A. Cardinali<fnref n="27" />,
G. Casini<fnref n="28" />, R. Catalano<fnref n="1" />, M. Cavallaro<fnref n="1" />, S. Ceccuzzi<fnref n="29" />, L. Celona<fnref n="1" />, S. Cherubini<fnref n="1" />,<fnref n="2" />, A. Chieffi<fnref n="24" />,³⁰, I. Ciraldo<fnref n="1" />,<fnref n="2" />,
G. Ciullo³¹,³², M. Colonna<fnref n="1" />, L. Cosentino<fnref n="1" />, G. Cuttone<fnref n="1" />, G. D'Agata<fnref n="1" />,<fnref n="2" />, G. De Gregorio<fnref n="4" />,³³, S. Degl'Innocenti³⁴,
F. Delaunay<fnref n="1" />,<fnref n="2" />,³⁵, L. Di Donato<fnref n="1" />,³⁶, A. Di Nitto<fnref n="4" />,<fnref n="8" />, T. Dickel³⁷,³⁸, D. Doria<fnref n="17" />,³⁹, J. E. Ducret⁴⁰, M. Durante<fnref n="14" />, J. Esposito<fnref n="7" />,
F. Farrokhi<fnref n="1" />, J. P. Fernandez Garcia<fnref n="21" />, P. Figuera<fnref n="1" />, M. Fisichella<fnref n="1" />, Z. Fulop<fnref n="14" />, A. Galatá<fnref n="6" />, D. Galaviz Redondo⁴¹,
D. Gambacurta<fnref n="1" />, S. Gammino<fnref n="1" />, E. Geraci<fnref n="2" />,<fnref n="3" />, L. Gizzi⁴², B. Gnoffo<fnref n="2" />,<fnref n="3" />, F. Groppi<fnref n="26" />,<fnref n="27" />, G. L. Guardo<fnref n="1" />, M. Guarrera<fnref n="1" />,
S. Hayakawa⁴³, F. Horst<fnref n="14" />, S. Q. Hou⁴⁴, A. Jarota<fnref n="8" />, J. José⁴⁵, S. Kar<fnref n="18" />,⁴⁶, A. Karpov<fnref n="15" />, H. Kierzkowska-Pawlak<fnref n="9" />,
G. G. Kiss<fnref n="14" />, G. Knyazheva<fnref n="15" />, H. Koivisto⁴⁷, B. Koop⁷², E. Kozulin<fnref n="14" />, D. Kumar³⁷,³⁸, A. Kurmanova<fnref n="1" />, G. La Rana<fnref n="4" />,<fnref n="8" />,
L. Labate⁴², L. Lamia<fnref n="1" />,<fnref n="2" />, E. G. Lanza<fnref n="3" />, J. A. Lay⁴⁸,⁴⁹, D. Lattuada<fnref n="1" />,<fnref n="6" />, H. Lenske⁵⁰, M. Limongi<fnref n="24" />,³⁰,⁵¹, M. Lipoglavsek⁵²,
I. Lombardo<fnref n="2" />,<fnref n="3" />, A. Mairani⁷², S. Manetti<fnref n="26" />,<fnref n="27" />, M. Marafini⁷¹, L. Marcucci³⁴, D. Margarone⁵³, N. S. Martorana<fnref n="1" />,<fnref n="3" />,
L. Maunoury⁴⁰, G. S. Mauro<fnref n="1" />, M. Mazzaglia<fnref n="1" />, S. Mein⁷², A. Mengoni<fnref n="5" />,⁵⁴, M. Milin⁵⁵, B. Mishra<fnref n="1" />, L. Mou<fnref n="7" />, J. Mrazek⁵⁶,
P. Nadtochy⁵⁷, E. Naselli<fnref n="1" />, P. Nicolai<fnref n="12" />, K. Novikov<fnref n="15" />, A. A. Oliva<fnref n="1" />, A. Pagano<fnref n="3" />, E. V. Pagano<fnref n="1" />, S. Palmerini<fnref n="23" />,<fnref n="24" />, M. Papa<fnref n="3" />,
K. Parodi⁷³, V. Patera⁵⁸, J. Pellumaj<fnref n="7" />,³¹, C. Petrone<fnref n="24" />, S. Piantelli<fnref n="28" />, D. Pierroutsakou<fnref n="4" />, F. Pinna<fnref n="25" />, G. Politi<fnref n="2" />,<fnref n="3" />,
I. Postuma<fnref n="19" />,<fnref n="20" />, P. Prajapati<fnref n="1" />,⁵⁹, P. G. Prada Moroni³⁵, G. Pupillo<fnref n="7" />, D. Raffestin<fnref n="12" />, R. Racz<fnref n="14" />, C.-A. Reidel<fnref n="14" />,
D. Rifuggiato<fnref n="1" />, F. Risitano<fnref n="3" />,⁶⁰, F. Rizzo<fnref n="2" />,<fnref n="3" />, X. Roca Maza⁶¹,⁶², S. Romano<fnref n="1" />,<fnref n="2" />, L. Roso⁶³, F. Rotaru<fnref n="17" />, A. D. Russo<fnref n="1" />,
P. Russotto<fnref n="1" />, V. Saiko<fnref n="15" />, D. Santonocito<fnref n="1" />, E. Santopinto⁶⁴, G. Sarri⁴⁶, D. Sartirana<fnref n="25" />, C. Schuy<fnref n="14" />, O. Sgouros<fnref n="1" />,
S. Simonucci⁶⁵, G. Sorbello<fnref n="1" />,³⁶, V. Soukeras<fnref n="1" />, R. Spartá<fnref n="1" />, A. Spatafora<fnref n="1" />,<fnref n="2" />, M. Stanoiu<fnref n="17" />, S. Taioli⁶⁶,⁶⁷,⁶⁸, T. Tessonnier⁷²,
P. Thirolf⁷³, E. Tognelli³⁴, D. Torresi<fnref n="1" />, G. Torrisi<fnref n="1" />, L. Trache<fnref n="17" />, G. Traini⁷⁰, M. Trimarchi<fnref n="3" />,⁶⁰, S. Tsikata⁶⁹, A. Tumino<fnref n="1" />,<fnref n="6" />,
J. Tyczkowski<fnref n="9" />, H. Yamaguchi⁴³, V. Vercesi<fnref n="19" />,<fnref n="20" />, I. Vidana<fnref n="3" />, L. Volpe⁶³, U. Weber<fnref n="14" />

<footnote n="1">¹ Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, 95123 Catania, Italy</footnote>

<footnote n="2">² Dipartimento di Fisica e Astronomia “Ettore Majorana”, University of Catania, 95123 Catania, Italy</footnote>

<footnote n="3">³ Sezione di Catania, Istituto Nazionale di Fisica Nucleare, 95123 Catania, Italy</footnote>

<footnote n="4">⁴ Sezione di Napoli, Istituto Nazionale di Fisica Nucleare, 80126 Napoli, Italy</footnote>

<footnote n="5">⁵ Sezione di Bologna, Istituto Nazionale di Fisica Nucleare, 40127 Bologna, Italy</footnote>

<footnote n="6">⁶ Facoltà di Ingegneria e Architettura, Università degli Studi di Enna “Kore”, 94100 Enna, Italy</footnote>

<footnote n="7">⁷ Laboratori Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare, 35020 Legnaro, Italy</footnote>

<footnote n="8">⁸ Dipartimento di Fisica “Ettore Pancini”, Università di Napoli Federico II, 80126 Napoli, Italy</footnote>

<footnote n="9">⁹ Department of Molecular Engineering, Faculty of Process and Environmental Engineering, Lodz University of Technology, 93-005 Lodz, Poland</footnote>

<footnote n="10">¹⁰ Instituto de Fisica, Universidad Nacional Autonoma de Mexico, 04510 Mexico City, Mexico</footnote>

<footnote n="11">¹¹ Cyclotron Institute, Texas A&M University, College Station, TX 77840, USA</footnote>

<footnote n="12">¹² Centre Lasers Intenses et Applications (CELIA), University of Bordeaux, 33400 Talence, Bordeaux, France</footnote>

<footnote n="13">¹³ Department of Physics and Astronomy, Texas A&M University-Commerce, Commerce, TX 75429-3011, USA</footnote>

<footnote n="14">¹⁴ Atomki, Institute of Nuclear Research, 4026 Debrecen, Hungary</footnote>

<footnote n="15">¹⁵ Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, Dubna, Russia 141980</footnote>

<footnote n="16">¹⁶ Osservatorio Astrofisico di Catania, INAF, via S.Sofia 78, 95123 Catania, Italy</footnote>

<footnote n="17">¹⁷ IFIN-HH “Horia Hulubei”, National Institute of Physics and Nuclear Engineering, 077125 Magurele, Romania</footnote>

<footnote n="18">¹⁸ School of Mathematics and Physics, Centre for Plasma Physics, Queen’s University, Belfast, Northern Ireland BT7 1NN, UK</footnote>

<footnote n="19">¹⁹ Dipartimento di Fisica, Università degli Studi di Pavia, Via Agostino Bassi, 6, 27100 Pavia, Italy</footnote>

<footnote n="20">²⁰ Sezione di Pavia, Istituto Nazionale di Fisica Nucleare (INFN), Via Agostino Bassi, 6, 27100 Pavia, Italy</footnote>

<footnote n="21">²¹ Departamento de Física Atómica Molecular y Nuclear, University of Seville, 41012 Sevilla, Spain</footnote>

<footnote n="22">²² Fachbereich Physik, Institut für Kernphysik, Technische Universität Darmstadt, 61010 Darmstadt, Germany</footnote>

<footnote n="23">²³ Dipartimento di Fisica e Geologia, Università di Perugia, 06125 Perugia, Italy</footnote>

<footnote n="24">²⁴ Sezione di Perugia, Istituto Nazionale di Fisica Nucleare, 06125 Perugia, Italy</footnote>

<footnote n="25">²⁵ Sezione di Torino, Istituto Nazionale di Fisica Nucleare, 10125 Torino, Italy</footnote>

<footnote n="26">²⁶ DISAT, Politecnico di Torino, 10129 Torino, Italy</footnote>

<footnote n="27">²⁷ FSN Department, ENEA, DTT S.C.a r.l., 00044 Frascati, Italy</footnote>

<footnote n="28">²⁸ Sezione di Firenze, Istituto Nazionale di Fisica Nucleare, 50019 Sesto Fiorentino (Fi), Italy</footnote>

<footnote n="29">²⁹ ENEA, DTT S.C.a r.l., 00044 Frascati, Italy</footnote>

<footnote>ᵃ e-mail: lacognata@lns.infn.it</footnote>

<footnote>ᵇ e-mail: grapisarda@lns.infn.it (corresponding author)</footnote>
30 Osservatorio di Roma, INAF, Monteporzio Catone, Italy

31 Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara, 44122 Ferrara, Italy

32 Sezione di Ferrara, Istituto Nazionale di Fisica Nucleare, 44122 Ferrara, Italy

33 Dipartimento di Matematica e Fisica, Università degli Studi della Campania, 81100 Caserta, Italy

34 Dipartimento di Fisica, Università di Pisa, Pisa, Italy

35 LPC Caen, ENSICAEN, UNICAEN, CNRS/INP3, Normandie Université, Caen, France

36 Dipartimento di Ingegneria Elettrica, Elettronica e Informatica, Università degli Studi di Catania, 95125 Catania, Italy

37 GSI Helmholtz Centre for Heavy Ion Research GmbH, 64291 Darmstadt, Germany

38 Justus-Liebig University of Giessen, 35390 Giessen, Germany

39 Extreme Light Infrastructure-Nuclear Physics (ELI-NP), 077125 Bucharest-Magurele, Romania

40 Grand Accélérateur National d'Ions Lourds, 14000 Caen, France

41 Nuclear Physics Center, University of Lisbon, Lisboa, Portugal

42 Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche, Pisa, Italy

43 CNS, University of Tokyo, RIKEN Campus, Wakoshi, Japan

44 IMP, University of Lanzhou, Lanzhou, China

45 Physics Department, Universitat Politècnica de Catalunya, Barcelona, Spain

46 School of Mathematics and Physics, The Queen's University of Belfast, BT7 1NN Belfast, UK

47 Department of Physics, University of Jyväskylä, Jyväskylä, Finland

48 FAMN, University of Seville, 41004 Seville, Spain

49 Instituto Interuniversitario Carlos I de Física Teórica y Computacional, Seville, Spain

50 Institut für Theoretische Physik, Justus-Liebig-Universität Giessen, 35392 Giessen, Germany

51 Kavli Institute for the Physics and Mathematics of the Universe, Todai Institutes for Advanced Study, University of Tokyo, Kashiwa 277-8583, Japan

52 Jozef Stefan Institute, Lubiana, Slovenia

53 ELI-Beamlines, Institute of Physics ASCR, v.v.i (FZU), 18221 Prague, Czech Republic

54 ENEA, Department of Fusion and Technology for Nuclear Safety and Security, 40127 Bologna, Italy

55 Department of Physics, University of Zagreb, 10000 Zagreb, Croatia

56 Cyclotron Institute, Academy of Science of Czech Republic, Rez, Praha, Czech Republic

57 Omsk State Technical University, Omsk, Russia 644050

58 Università “La Sapienza”, Roma, Italy

59 Manipal Centre for Natural Sciences, MAHE, Manipal 576 104, India

60 Dipartimento di Scienze Matematiche e Informatiche, Scienze Fisiche e Scienze della Terra (MIFT), University of Messina, 98166 Messina, Italy

61 Dipartimento di Fisica, Università degli Studi di Milano, 20133 Milano, Italy

62 Sezione di Milano, Istituto Nazionale di Fisica Nucleare, 20133 Milano, Italy

63 CPLU, Centro de Laseres Pulsados, Salamanca, Spain

64 Sezione di Genova, Istituto Nazionale di Fisica Nucleare, 16146 Genova, Italy

65 Physics Department, University of Camerino, Camerino, Italia

66 Trento Institute for Fundamental Physics and Applications, TIFPA-INFN, 38123 Trento, Italy

67 European Centre for Theoretical Studies in Nuclear Physics and Related Areas, Fondazione Bruno Kessler, 38123 Trento, Italy

68 World-Class Research Center for Advanced Digital Technologies, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia 195251

69 Centre National de la Recherche Scientifique (CNRS), ICARE UPR 3021, 45071 Orléans, France

70 Sezione di Roma, Istituto Nazionale di Fisica Nucleare (INFN), Piazzale Aldo Moro, 2, 00158 Roma, Italy

71 Centro Studi e Ricerche Enrico Fermi, Via Panisperna, 89, 00184 Roma, Italy

72 Heidelberg Ion-Beam Therapy Center (HIT), Im Neuenheimer Feld, 450, 69120 Heidelberg, Germany

73 Department of Medical Physics, Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, 80539 Munich, Germany

Received: 3 March 2023 / Accepted: 1 August 2023

© The Author(s) 2023

**Abstract** The next years will see the completion of several new facilities at Istituto Nazionale di Fisica Nucleare – Laboratori Nazionali del Sud (LNS) opening up new possibilities in the fields of nuclear structure, nuclear dynamics, nuclear astrophysics and applications. These include a new line for high-intensity cyclotron beams, a new facility for in-flight production of radioactive ion beams, the PANDORA plasma trap for multidisciplinary studies and a high-power laser for basic science and applied physics. The nuclear physics community has organized a workshop to discuss the new physics opportunities that will be possible in the middle term (5–7 years) by employing state-of-the-art detection systems. A detailed discussion of the outcome from the workshop is presented in this report.

**Abbreviations**

ANC Asymptotic normalization coefficient

BNCT Boron-neutron capture therapy

BNV Boltzmann-Nordheim-Vlasov

CoMD Constrained molecular dynamics

CPLU Centre de Laseres Pulsados
30 Osservatorio di Roma, INAF, Monteporzio Catone, Italy

31 Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara, 44122 Ferrara, Italy

32 Sezione di Ferrara, Istituto Nazionale di Fisica Nucleare, 44122 Ferrara, Italy

33 Dipartimento di Matematica e Fisica, Università degli Studi della Campania, 81100 Caserta, Italy

34 Dipartimento di Fisica, Università di Pisa, Pisa, Italy

35 LPC Caen, ENSICAEN, UNICAEN, CNRS/INP3, Normandie Université, Caen, France

36 Dipartimento di Ingegneria Elettrica, Elettronica e Informatica, Università degli Studi di Catania, 95125 Catania, Italy

37 GSI Helmholtz Centre for Heavy Ion Research GmbH, 64291 Darmstadt, Germany

38 Justus-Liebig University of Giessen, 35390 Giessen, Germany

39 Extreme Light Infrastructure-Nuclear Physics (ELI-NP), 077125 Bucharest-Magurele, Romania

40 Grand Accélérateur National d'Ions Lourds, 14000 Caen, France

41 Nuclear Physics Center, University of Lisbon, Lisboa, Portugal

42 Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche, Pisa, Italy

43 CNS, University of Tokyo, RIKEN Campus, Wakoshi, Japan

44 IMP, University of Lanzhou, Lanzhou, China

45 Physics Department, Universitat Politècnica de Catalunya, Barcelona, Spain

46 School of Mathematics and Physics, The Queen's University of Belfast, BT7 1NN Belfast, UK

47 Department of Physics, University of Jyväskylä, Jyväskylä, Finland

48 FAMN, University of Seville, 41004 Seville, Spain

49 Instituto Interuniversitario Carlos I de Física Teórica y Computacional, Seville, Spain

50 Institut für Theoretische Physik, Justus-Liebig-Universität Giessen, 35392 Giessen, Germany

51 Kavli Institute for the Physics and Mathematics of the Universe, Todai Institutes for Advanced Study, University of Tokyo, Kashiwa 277-8583, Japan

52 Jozef Stefan Institute, Lubiana, Slovenia

53 ELI-Beamlines, Institute of Physics ASCR, v.v.i (FZU), 18221 Prague, Czech Republic

54 ENEA, Department of Fusion and Technology for Nuclear Safety and Security, 40127 Bologna, Italy

55 Department of Physics, University of Zagreb, 10000 Zagreb, Croatia

56 Cyclotron Institute, Academy of Science of Czech Republic, Rez, Praha, Czech Republic

57 Omsk State Technical University, Omsk, Russia 644050

58 Università “La Sapienza”, Roma, Italy

59 Manipal Centre for Natural Sciences, MAHE, Manipal 576 104, India

60 Dipartimento di Scienze Matematiche e Informatiche, Scienze Fisiche e Scienze della Terra (MIFT), University of Messina, 98166 Messina, Italy

61 Dipartimento di Fisica, Università degli Studi di Milano, 20133 Milano, Italy

62 Sezione di Milano, Istituto Nazionale di Fisica Nucleare, 20133 Milano, Italy

63 CPLU, Centro de Laseres Pulsados, Salamanca, Spain

64 Sezione di Genova, Istituto Nazionale di Fisica Nucleare, 16146 Genova, Italy

65 Physics Department, University of Camerino, Camerino, Italia

66 Trento Institute for Fundamental Physics and Applications, TIFPA-INFN, 38123 Trento, Italy

67 European Centre for Theoretical Studies in Nuclear Physics and Related Areas, Fondazione Bruno Kessler, 38123 Trento, Italy

68 World-Class Research Center for Advanced Digital Technologies, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia 195251

69 Centre National de la Recherche Scientifique (CNRS), ICARE UPR 3021, 45071 Orléans, France

70 Sezione di Roma, Istituto Nazionale di Fisica Nucleare (INFN), Piazzale Aldo Moro, 2, 00158 Roma, Italy

71 Centro Studi e Ricerche Enrico Fermi, Via Panisperna, 89, 00184 Roma, Italy

72 Heidelberg Ion-Beam Therapy Center (HIT), Im Neuenheimer Feld, 450, 69120 Heidelberg, Germany

73 Department of Medical Physics, Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, 80539 Munich, Germany

Received: 3 March 2023 / Accepted: 1 August 2023

© The Author(s) 2023

**Abstract** The next years will see the completion of several new facilities at Istituto Nazionale di Fisica Nucleare – Laboratori Nazionali del Sud (LNS) opening up new possibilities in the fields of nuclear structure, nuclear dynamics, nuclear astrophysics and applications. These include a new line for high-intensity cyclotron beams, a new facility for in-flight production of radioactive ion beams, the PANDORA plasma trap for multidisciplinary studies and a high-power laser for basic science and applied physics. The nuclear physics community has organized a workshop to discuss the new physics opportunities that will be possible in the middle term (5–7 years) by employing state-of-the-art detection systems. A detailed discussion of the outcome from the workshop is presented in this report.

**Abbreviations**

ANC Asymptotic normalization coefficient

BNCT Boron-neutron capture therapy

BNV Boltzmann-Nordheim-Vlasov

CoMD Constrained molecular dynamics

CPLU Centre de Laseres Pulsados
<table><tr><td>DWBA</td><td>Distorted-wave Born approximation</td></tr><tr><td>ECR</td><td>Electron cyclotron resonance</td></tr><tr><td>ECR-CB</td><td>Electron cyclotron resonance-based charge breeder</td></tr><tr><td>ED</td><td>Electrostatic deflector</td></tr><tr><td>EOS</td><td>Equation of state</td></tr><tr><td>FPT</td><td>Flexible plasma trap</td></tr><tr><td>GDR</td><td>Giant dipole resonances</td></tr><tr><td>GR</td><td>Giant resonances</td></tr><tr><td>HIBs</td><td>High-intensity beams</td></tr><tr><td>HIT</td><td>Hidelberg ion therapy</td></tr><tr><td>ICH</td><td>Ion cyclotron heating</td></tr><tr><td>ICRH</td><td>Ion cyclotron resonance heating</td></tr><tr><td>ICH-CT</td><td>Ion cyclotron heating antennas for compact traps</td></tr><tr><td>ISGMR</td><td>Isoscalar giant monopole resonance</td></tr><tr><td>LET</td><td>Linear energy transfer</td></tr><tr><td>LWFA</td><td>Laser wakefield acceleration</td></tr><tr><td>MIRT</td><td>Multi-ion radiotherapy</td></tr><tr><td>MIT</td><td>Multi-ion therapy</td></tr><tr><td>NIRS</td><td>National Institute of Radiological Sciences</td></tr><tr><td>PALS</td><td>Positron annihilation lifetime spectroscopy</td></tr><tr><td>PDR</td><td>Pygmy dipole resonances</td></tr><tr><td>PET</td><td>Positron emission tomography</td></tr><tr><td>RBE</td><td>Relative biological effectiveness</td></tr><tr><td>RF</td><td>Radio-frequency</td></tr><tr><td>RIBs</td><td>Radioactive ion beams</td></tr><tr><td>RPA</td><td>Radiation pressure acceleration</td></tr><tr><td>SC</td><td>Superconductive cyclotron</td></tr><tr><td>THM</td><td>Trojan horse method</td></tr><tr><td>uHDR</td><td>Ultrahigh dose rates</td></tr><tr><td>WDM</td><td>Warm dense matter</td></tr></table>

# 1 Executive summary

The LNS is an user-oriented large-scale facility dedicated to basic nuclear and subnuclear physics studies and to the development of applications with important benefit for society. The LNS accelerator complex consists of a K-800 superconducting cyclotron (SC) and a 13.5 MV Tandem. To fulfill the requests of users aiming to study rare processes in nuclear physics, a significant upgrade of the entire setup is currently in progress. The availability of new beams and new facilities (discussed in Sect. 2) called for a thorough discussion on the midterm research plan to be carried out. The Nuclear Physics Mid Term Plan in Italy made it possible to trigger and coordinate new ideas proposed by the international community interested in such experimentations, in particular by younger nuclear physics researchers that will be the leading force in the exploitation of the new facilities. The LNS session of the workshop included four working groups on nuclear dynamics, nuclear structure, nuclear astrophysics and applications, involving experimentalists and theoretists.

This initiative follows the previous INFN Nuclear Physics Division joint works on nuclear astrophysics [1] and on particle identification [2].

## 1.1 Nuclear dynamics

Nuclear dynamics includes a large number of phenomena that allow to explore the relevant properties of the nuclear medium. Heavy-ion collisions (HIC) represent a powerful tool of investigation in this field, spanning a wide range of energies at LNS and creating different regimes of nuclear matter. In this way they could provide information on various aspects, from the features of nuclear equation of state (EOS) to the structure of nuclei and their decay modes, up to the dynamics of the nuclear reactions to produce nuclei in the region of “terra incognita”, far from the stability valley. In the framework of nuclear dynamics, three principal subjects “Heavy-Ion Collision and Equation of State” (Sect. 3.1), “Clustering” (Sect. 3.2) and “Fission Dynamics” (Sect. 3.3) were addressed.

Section 3.1 explores some new ideas and devices that, by using stable and radioactive beams at LNS in the Fermi energy domain, will improve the precision and the reliability of the symmetry energy constraints at densities below saturation ($\rho \le 0.17\text{fm}^{-3}$). In particular, the symmetry energy will be investigated through the study of the dynamical dipole, an observable connected to the
<table><tr><td>DWBA</td><td>Distorted-wave Born approximation</td></tr><tr><td>ECR</td><td>Electron cyclotron resonance</td></tr><tr><td>ECR-CB</td><td>Electron cyclotron resonance-based charge breeder</td></tr><tr><td>ED</td><td>Electrostatic deflector</td></tr><tr><td>EOS</td><td>Equation of state</td></tr><tr><td>FPT</td><td>Flexible plasma trap</td></tr><tr><td>GDR</td><td>Giant dipole resonances</td></tr><tr><td>GR</td><td>Giant resonances</td></tr><tr><td>HIBs</td><td>High-intensity beams</td></tr><tr><td>HIT</td><td>Hidelberg ion therapy</td></tr><tr><td>ICH</td><td>Ion cyclotron heating</td></tr><tr><td>ICRH</td><td>Ion cyclotron resonance heating</td></tr><tr><td>ICH-CT</td><td>Ion cyclotron heating antennas for compact traps</td></tr><tr><td>ISGMR</td><td>Isoscalar giant monopole resonance</td></tr><tr><td>LET</td><td>Linear energy transfer</td></tr><tr><td>LWFA</td><td>Laser wakefield acceleration</td></tr><tr><td>MIRT</td><td>Multi-ion radiotherapy</td></tr><tr><td>MIT</td><td>Multi-ion therapy</td></tr><tr><td>NIRS</td><td>National Institute of Radiological Sciences</td></tr><tr><td>PALS</td><td>Positron annihilation lifetime spectroscopy</td></tr><tr><td>PDR</td><td>Pygmy dipole resonances</td></tr><tr><td>PET</td><td>Positron emission tomography</td></tr><tr><td>RBE</td><td>Relative biological effectiveness</td></tr><tr><td>RF</td><td>Radio-frequency</td></tr><tr><td>RIBs</td><td>Radioactive ion beams</td></tr><tr><td>RPA</td><td>Radiation pressure acceleration</td></tr><tr><td>SC</td><td>Superconductive cyclotron</td></tr><tr><td>THM</td><td>Trojan horse method</td></tr><tr><td>uHDR</td><td>Ultrahigh dose rates</td></tr><tr><td>WDM</td><td>Warm dense matter</td></tr></table>

# 1 Executive summary

The LNS is an user-oriented large-scale facility dedicated to basic nuclear and subnuclear physics studies and to the development of applications with important benefit for society. The LNS accelerator complex consists of a K-800 superconducting cyclotron (SC) and a 13.5 MV Tandem. To fulfill the requests of users aiming to study rare processes in nuclear physics, a significant upgrade of the entire setup is currently in progress. The availability of new beams and new facilities (discussed in Sect. 2) called for a thorough discussion on the midterm research plan to be carried out. The Nuclear Physics Mid Term Plan in Italy made it possible to trigger and coordinate new ideas proposed by the international community interested in such experimentations, in particular by younger nuclear physics researchers that will be the leading force in the exploitation of the new facilities. The LNS session of the workshop included four working groups on nuclear dynamics, nuclear structure, nuclear astrophysics and applications, involving experimentalists and theoretists.

This initiative follows the previous INFN Nuclear Physics Division joint works on nuclear astrophysics [1] and on particle identification [2].

## 1.1 Nuclear dynamics

Nuclear dynamics includes a large number of phenomena that allow to explore the relevant properties of the nuclear medium. Heavy-ion collisions (HIC) represent a powerful tool of investigation in this field, spanning a wide range of energies at LNS and creating different regimes of nuclear matter. In this way they could provide information on various aspects, from the features of nuclear equation of state (EOS) to the structure of nuclei and their decay modes, up to the dynamics of the nuclear reactions to produce nuclei in the region of “terra incognita”, far from the stability valley. In the framework of nuclear dynamics, three principal subjects “Heavy-Ion Collision and Equation of State” (Sect. 3.1), “Clustering” (Sect. 3.2) and “Fission Dynamics” (Sect. 3.3) were addressed.

Section 3.1 explores some new ideas and devices that, by using stable and radioactive beams at LNS in the Fermi energy domain, will improve the precision and the reliability of the symmetry energy constraints at densities below saturation ($ρ ≤ 0.17fm^{-3}$). In particular, the symmetry energy will be investigated through the study of the dynamical dipole, an observable connected to the
<figure><img src="image_3.png" /><figcaption>Fig. 1 Highlight for nuclear dynamics for the three items and temporal phases A, B and C</figcaption></figure>

stiffness parameter, and by using advanced multidetectors such as CHIMERA, FARCOS and FAZIA, also coupling new devices for neutron detection. FraISe (Sect. 2.2.2) beams will be particularly important to span a broad isospin range.

The working group on “Clustering” (Sect. 3.2) proposes some new ideas to carry out very precise measurements of already known cluster states in a number of key nuclei and to search for new cluster structures and their decays, in previously unstudied nuclei or even new mass regions. Investigations of cluster states other than providing results on the clustering effects can also show the presence of neutron halos and skins, or α-condensate structures, especially in medium-light nuclei. Tandem beams (including long-lived radioactive nuclei, see Sect. 5 and noble gas beams, Sect. 5.1.1) will be used in parallel to FraISe beams.

The “Fission Dynamics” working group (Sect. 3.3) has focused on shell effects in fission and quasifission (Sect. 3.3.1), on multinucleon transfer reactions to investigate “Terra Incognita” (Sect. 3.3.1), and on possible alternative paths to produce superheavy elements (Sect. 3.3.5), mostly using high-intensity cyclotron beams as cross sections can be as low as few pb. Besides the theoretical developments, new tools such as the addition of a time-of-flight arm to the MAGNEX spectrometer (Sect. 2.3) will be necessary to carry out the research program.

The time phases for the different physics programs are shown in Fig. 1, where A, B and C are used for the shorter to longer time intervals. The detailed timeline is presented in Table 4.

## 1.2 Nuclear structure

Nuclear structure (Sect. 4) addresses static properties of nuclei in their ground and excited states. These studies are characterized by important interfaces to nuclear dynamics. New ideas were gathered along two lines: the study of the nuclear matrix elements (NMEs) toward neutrinoless double-beta decay $0\nu\beta\beta$-decays (Sect. 4.1), with a synergistic work on the development of theoretical models and on the combined use of high-intensity beams and advanced spectrometry; and the study of collectivity in nuclei (Sect. 4.2).

The working group on NME focuses on single charge exchange (SCE) and double charge exchange (DCE) reactions (Sect. 4.1.2) induced by heavy ions as well as double γ-decay process (Sect. 4.1.6) to reduce uncertainties in the calculations of the NME. Indeed, the NME is a crucial ingredient in the expression of the $0\nu\beta\beta$ half-life, describing the transition probability of nuclear processes. To date, results produced by different models to evaluate NME show a spread by a factor of three, leading to big uncertainties both on the amount of material required in the experiments and on the neutrino mass. To this purpose, state-of-the-art nuclear structure models (realistic SM, Skyrme-QRPA and IBMs, see Sect. 4.1.7 for details) will be developed to provide the input for direct and transfer heavy-ion SCE and DCE reactions.

As discussed in Sect. 4.1, the idea is to use heavy-ion DCE reactions to acquire information on the $0\nu\beta\beta$ decay exploiting possible analogies between the two processes, as already pointed out for single CE excitations and β decay. To acquire experimental information on the $0\nu\beta\beta$ NMEs, the NUMEN project proposes to use heavy-ion DCE reactions, with high-intensity beams and advanced spectrometry, as surrogates for $0\nu\beta\beta$ decays. Although their different nature, these two processes, in fact, show possible analogies as discussed in Sect. 4.1.1.

Improved statistics using high-intensity beams from the LNS SC will make it possible to extend the studies to a larger number of systems presently not accessible due to the low cross sections. In the experimental approach to DCE reactions, a key tool will be the
<figure><img src="image_3.png" /><figcaption>Fig. 1 Highlight for nuclear dynamics for the three items and temporal phases A, B and C</figcaption></figure>

stiffness parameter, and by using advanced multidetectors such as CHIMERA, FARCOS and FAZIA, also coupling new devices for neutron detection. FraISe (Sect. 2.2.2) beams will be particularly important to span a broad isospin range.

The working group on “Clustering” (Sect. 3.2) proposes some new ideas to carry out very precise measurements of already known cluster states in a number of key nuclei and to search for new cluster structures and their decays, in previously unstudied nuclei or even new mass regions. Investigations of cluster states other than providing results on the clustering effects can also show the presence of neutron halos and skins, or α-condensate structures, especially in medium-light nuclei. Tandem beams (including long-lived radioactive nuclei, see Sect. 5 and noble gas beams, Sect. 5.1.1) will be used in parallel to FraISe beams.

The “Fission Dynamics” working group (Sect. 3.3) has focused on shell effects in fission and quasifission (Sect. 3.3.1), on multinucleon transfer reactions to investigate “Terra Incognita” (Sect. 3.3.1), and on possible alternative paths to produce superheavy elements (Sect. 3.3.5), mostly using high-intensity cyclotron beams as cross sections can be as low as few pb. Besides the theoretical developments, new tools such as the addition of a time-of-flight arm to the MAGNEX spectrometer (Sect. 2.3) will be necessary to carry out the research program.

The time phases for the different physics programs are shown in Fig. 1, where A, B and C are used for the shorter to longer time intervals. The detailed timeline is presented in Table 4.

## 1.2 Nuclear structure

Nuclear structure (Sect. 4) addresses static properties of nuclei in their ground and excited states. These studies are characterized by important interfaces to nuclear dynamics. New ideas were gathered along two lines: the study of the nuclear matrix elements (NMEs) toward neutrinoless double-beta decay $0\nu\beta\beta$-decays (Sect. 4.1), with a synergistic work on the development of theoretical models and on the combined use of high-intensity beams and advanced spectrometry; and the study of collectivity in nuclei (Sect. 4.2).

The working group on NME focuses on single charge exchange (SCE) and double charge exchange (DCE) reactions (Sect. 4.1.2) induced by heavy ions as well as double γ-decay process (Sect. 4.1.6) to reduce uncertainties in the calculations of the NME. Indeed, the NME is a crucial ingredient in the expression of the $0\nu\beta\beta$ half-life, describing the transition probability of nuclear processes. To date, results produced by different models to evaluate NME show a spread by a factor of three, leading to big uncertainties both on the amount of material required in the experiments and on the neutrino mass. To this purpose, state-of-the-art nuclear structure models (realistic SM, Skyrme-QRPA and IBMs, see Sect. 4.1.7 for details) will be developed to provide the input for direct and transfer heavy-ion SCE and DCE reactions.

As discussed in Sect. 4.1, the idea is to use heavy-ion DCE reactions to acquire information on the $0\nu\beta\beta$ decay exploiting possible analogies between the two processes, as already pointed out for single CE excitations and β decay. To acquire experimental information on the $0\nu\beta\beta$ NMEs, the NUMEN project proposes to use heavy-ion DCE reactions, with high-intensity beams and advanced spectrometry, as surrogates for $0\nu\beta\beta$ decays. Although their different nature, these two processes, in fact, show possible analogies as discussed in Sect. 4.1.1.

Improved statistics using high-intensity beams from the LNS SC will make it possible to extend the studies to a larger number of systems presently not accessible due to the low cross sections. In the experimental approach to DCE reactions, a key tool will be the
<figure><img src="image_4.png" /><figcaption>**Fig. 2** Highlight for nuclear structure for the three items and temporal phases A, B and C</figcaption></figure>

MAGNEX 2.3 magnetic spectrometer, with its upgrade to sustain high rates and at the same time to maintain the current resolution and sensitivity.

An additional topic is the investigation of collectivity in nuclei (Sect. 4.2), using FraISe (Sect. 2.2.2) beams in combination with the multidetectors available at LNS. In detail, FraISe day-one experiments will be devoted to Pigmy dipole resonance (PDR) search and then dynamical dipole studies in reactions induced by Ar isotopes on Ca or Ni isotope will be addressed. Phenomena linked with the giant dipole resonance (GDR), such as quenching of the GDR γ-ray yield and its disappearance with the liquid-gas phase transition will be also investigated, in connection with the nuclear dynamics working group.

The time phases for the different physics programs are shown in Fig. 2, with the same meaning for the three time steps. The detailed timeline is presented in Table 5.

## 1.3 Nuclear astrophysics

Nuclear astrophysics (Sect. 5) is an interdisciplinary field which connects astrophysics (mainly stellar physics and cosmological nucleosynthesis) to experimental techniques of low-energy cross section measurements and nuclear physics theory. In the last two decades, the measurements/calculations of many cross sections of astrophysical interest have been greatly improved. However, in several cases present uncertainties still affect the predictions for stellar characteristics and element nucleosynthesis. LNS has undoubtedly played a leading role within this framework with its stable and unstable beams.

In Sect. 5.1, “Nuclear and Atomic Inputs for Quiescent Stellar Evolution”, light elements depletion (Sect. 5.1.1) will be studied, in particular addressing the cosmological lithium problem, to date the most critical issue in our understanding of the early universe. Its investigation will benefit from the possibility of studying ⁷Be half-life (Sect. 5.1.2) in strongly ionized stellar environments by means of the PANDORA plasma trap (Sect. 2.3). Reaction involving heavier ions, taking place in advanced stellar evolutionary stages such as carbon and oxygen burning (Sect. 5.1.3) and NeNaAl cycle (Sect. 5.1.4), will be also studied using direct and indirect methods, especially thanks to the availability of the NESTOR source to be installed at the LNS Tandem. Also, nuclear reactions in hot and dense plasmas similar to the astrophysical ones will be studied thanks to the availability of the I-LUCE facility (Sect. 2.3).

Astrophysical most violent phenomena such as Novae, Supernovae, X-Ray Bursts and neutron-star mergers involve unstable nuclei (Sect. 5.2.2). As already tested using ¹⁰Be, at LNS it will be possible to accelerate long-lived isotopes at Tandem (²⁶Al, ¹⁰Be, ⁴⁴Ti) at high intensities and angular/energy resolution, making it possible to understand, among others, the birth of the solar system. FraISe beams will be also used to access the isotopes far from the stability valley, exploring regions in the nuclear chart complementary to the ones reached by SPES.

Since nuclei heavier than iron are mostly produced through neutron captures (the so-called s- and r-processes), Sect. 5.3 is devoted to the direct and indirect studies of stellar neutron sources and neutron poisons (Sect. 5.3.1). A major role in shaping the path toward heavy ions is played by β-decays; PANDORA will allow very precise half-life/branching ratio measurements in stellar
<figure><img src="image_4.png" /><figcaption>**Fig. 2** Highlight for nuclear structure for the three items and temporal phases A, B and C</figcaption></figure>

MAGNEX 2.3 magnetic spectrometer, with its upgrade to sustain high rates and at the same time to maintain the current resolution and sensitivity.

An additional topic is the investigation of collectivity in nuclei (Sect. 4.2), using FraISe (Sect. 2.2.2) beams in combination with the multidetectors available at LNS. In detail, FraISe day-one experiments will be devoted to Pigmy dipole resonance (PDR) search and then dynamical dipole studies in reactions induced by Ar isotopes on Ca or Ni isotope will be addressed. Phenomena linked with the giant dipole resonance (GDR), such as quenching of the GDR γ-ray yield and its disappearance with the liquid-gas phase transition will be also investigated, in connection with the nuclear dynamics working group.

The time phases for the different physics programs are shown in Fig. 2, with the same meaning for the three time steps. The detailed timeline is presented in Table 5.

## 1.3 Nuclear astrophysics

Nuclear astrophysics (Sect. 5) is an interdisciplinary field which connects astrophysics (mainly stellar physics and cosmological nucleosynthesis) to experimental techniques of low-energy cross section measurements and nuclear physics theory. In the last two decades, the measurements/calculations of many cross sections of astrophysical interest have been greatly improved. However, in several cases present uncertainties still affect the predictions for stellar characteristics and element nucleosynthesis. LNS has undoubtedly played a leading role within this framework with its stable and unstable beams.

In Sect. 5.1, “Nuclear and Atomic Inputs for Quiescent Stellar Evolution”, light elements depletion (Sect. 5.1.1) will be studied, in particular addressing the cosmological lithium problem, to date the most critical issue in our understanding of the early universe. Its investigation will benefit from the possibility of studying ⁷Be half-life (Sect. 5.1.2) in strongly ionized stellar environments by means of the PANDORA plasma trap (Sect. 2.3). Reaction involving heavier ions, taking place in advanced stellar evolutionary stages such as carbon and oxygen burning (Sect. 5.1.3) and NeNaAl cycle (Sect. 5.1.4), will be also studied using direct and indirect methods, especially thanks to the availability of the NESTOR source to be installed at the LNS Tandem. Also, nuclear reactions in hot and dense plasmas similar to the astrophysical ones will be studied thanks to the availability of the I-LUCE facility (Sect. 2.3).

Astrophysical most violent phenomena such as Novae, Supernovae, X-Ray Bursts and neutron-star mergers involve unstable nuclei (Sect. 5.2.2). As already tested using ¹⁰Be, at LNS it will be possible to accelerate long-lived isotopes at Tandem (²⁶Al, ¹⁰Be, ⁴⁴Ti) at high intensities and angular/energy resolution, making it possible to understand, among others, the birth of the solar system. FraISe beams will be also used to access the isotopes far from the stability valley, exploring regions in the nuclear chart complementary to the ones reached by SPES.

Since nuclei heavier than iron are mostly produced through neutron captures (the so-called s- and r-processes), Sect. 5.3 is devoted to the direct and indirect studies of stellar neutron sources and neutron poisons (Sect. 5.3.1). A major role in shaping the path toward heavy ions is played by β-decays; PANDORA will allow very precise half-life/branching ratio measurements in stellar
<figure><img src="image_5.png" /><figcaption>Fig. 3 Highlight for nuclear astrophysics for the three physics programs and temporal phases A, B and C</figcaption></figure>

plasma for elements which are determinant for the s-process. Away from the stability valley, the POLYFEMO neutron detector will make it possible to characterize β-delayed neutron emission (Sect. 5.3.4). Along with the SC and the Tandem, laser beams will also make it possible to produce neutron beams for direct measurement of n-induced reactions (Sect. 5.3.2). Finally, the PANDORA facility may allow the measurement of opacities at electron densities and temperatures resembling some ejecta plasma conditions, shedding light on r-process-generated metallic species at specific time stages of the Kilonovae diffusion.

The time frame for the different physics programs is shown in Fig. 3. The detailed timeline is presented in Table 6.

## 1.4 Nuclear physics applications

Nuclear physics applications span a very broad range of topics. In Sect. 6 we will discuss the perspectives at the LNS for the coming years on this subject. We can identify three major scientific areas (medical, laser and plasma traps applications) also in relation to the main LNS facilities, the new laser system and the plasma trap PANDORA. Activities related to medical applications (Sect. 6.1) are well consolidated, starting from the 2000s with the construction of the CATANA facility for hadron therapy. Future study programs in this area are still focused on the availability of stable LNS beams, covering hot topics such as the flash radiotherapy and flash BNCT (boron-neutron capture therapy). The forthcoming high-intensity beams (HIBs) and radioactive ion beams (RIBs) that will be available at LNS in the near future (Sect. 6.1.2) will open new and interesting perspectives. In particular, RIBs can trigger new approaches for innovation on treatment methods that could be coupled with online contemporary diagnostic tools and will trigger cross section studies for new exotic radioisotopes and radiopharmaceutical drugs.

The near future of LNS research activities also involves the new high-power laser facility (Sect. 6.2) and the almost unique possibility to have, in the same experimental area, intense laser-accelerated and conventional ion beams. All the new acceleration schemes developed in the recent years triggered ideas and proposals for the development of new and compact laser-driven secondary sources (Sect. 6.2.1), for the measurement of stopping power in warm dense matter (Sect. 6.2.2) and for the hydrogen production from water by focused femtosecond laser pulses (Sect. 6.2.3).

In Sect. 6.3, the potential applications deriving from the developments related to the PANDORA facility are highlighted. The section is divided into three main topics: (i) magnetic plasmas and related issues (ions heating, charge breeding, stopping power, etc., Sect. 6.3.1); (ii) physics and technology aspects for fusion plasmas (Sect. 6.3.2); and (iii) innovative plasma chambers and resonators for compact reactors development (Sect. 6.3.3).

The timeline for the different physics programs is shown in Fig. 4. The detailed timeline is presented in Table 7.

# 2 Introduction

## 2.1 The LNS accelerator complex

The LNS accelerator complex consists of a K-800 superconducting cyclotron and a 13.5 MV Tandem.

The LNS superconducting cyclotron (SC) is a three-sector compact machine with a wide operating range, able to accelerate heavy ions of q/A from 0.1 to 0.5 at energies from 10 to 80 AMeV [3]. The SC has been in operation for more than 20 years, delivering beams mainly devoted to nuclear and applied physics experiments. The beam extraction efficiency, during its lifetime, has been
<figure><img src="image_5.png" /><figcaption>Fig. 3 Highlight for nuclear astrophysics for the three physics programs and temporal phases A, B and C</figcaption></figure>

plasma for elements which are determinant for the s-process. Away from the stability valley, the POLYFEMO neutron detector will make it possible to characterize β-delayed neutron emission (Sect. 5.3.4). Along with the SC and the Tandem, laser beams will also make it possible to produce neutron beams for direct measurement of n-induced reactions (Sect. 5.3.2). Finally, the PANDORA facility may allow the measurement of opacities at electron densities and temperatures resembling some ejecta plasma conditions, shedding light on r-process-generated metallic species at specific time stages of the Kilonovae diffusion.

The time frame for the different physics programs is shown in Fig. 3. The detailed timeline is presented in Table 6.

## 1.4 Nuclear physics applications

Nuclear physics applications span a very broad range of topics. In Sect. 6 we will discuss the perspectives at the LNS for the coming years on this subject. We can identify three major scientific areas (medical, laser and plasma traps applications) also in relation to the main LNS facilities, the new laser system and the plasma trap PANDORA. Activities related to medical applications (Sect. 6.1) are well consolidated, starting from the 2000s with the construction of the CATANA facility for hadron therapy. Future study programs in this area are still focused on the availability of stable LNS beams, covering hot topics such as the flash radiotherapy and flash BNCT (boron-neutron capture therapy). The forthcoming high-intensity beams (HIBs) and radioactive ion beams (RIBs) that will be available at LNS in the near future (Sect. 6.1.2) will open new and interesting perspectives. In particular, RIBs can trigger new approaches for innovation on treatment methods that could be coupled with online contemporary diagnostic tools and will trigger cross section studies for new exotic radioisotopes and radiopharmaceutical drugs.

The near future of LNS research activities also involves the new high-power laser facility (Sect. 6.2) and the almost unique possibility to have, in the same experimental area, intense laser-accelerated and conventional ion beams. All the new acceleration schemes developed in the recent years triggered ideas and proposals for the development of new and compact laser-driven secondary sources (Sect. 6.2.1), for the measurement of stopping power in warm dense matter (Sect. 6.2.2) and for the hydrogen production from water by focused femtosecond laser pulses (Sect. 6.2.3).

In Sect. 6.3, the potential applications deriving from the developments related to the PANDORA facility are highlighted. The section is divided into three main topics: (i) magnetic plasmas and related issues (ions heating, charge breeding, stopping power, etc., Sect. 6.3.1); (ii) physics and technology aspects for fusion plasmas (Sect. 6.3.2); and (iii) innovative plasma chambers and resonators for compact reactors development (Sect. 6.3.3).

The timeline for the different physics programs is shown in Fig. 4. The detailed timeline is presented in Table 7.

# 2 Introduction

## 2.1 The LNS accelerator complex

The LNS accelerator complex consists of a K-800 superconducting cyclotron and a 13.5 MV Tandem.

The LNS superconducting cyclotron (SC) is a three-sector compact machine with a wide operating range, able to accelerate heavy ions of q/A from 0.1 to 0.5 at energies from 10 to 80 AMeV [3]. The SC has been in operation for more than 20 years, delivering beams mainly devoted to nuclear and applied physics experiments. The beam extraction efficiency, during its lifetime, has been
<figure><img src="image_6.png" /><figcaption>Fig. 4 Highlight for nuclear physics applications for the three lines of research and temporal phases A, B and C</figcaption></figure>

<figure><img src="image_7.png" /><figcaption>Fig. 5 Ion-beam trajectories
calculated for stripping extraction</figcaption></figure>

lower than 60%, and for such a reason, the maximum beam power was limited to about 100 W, constrained by the beam power dissipation on the electrostatic deflectors.

To fulfill the request of users aiming to study rare processes in nuclear physics [4, 5] and provide high-intensity radioactive ion beams, complementary to those delivered by SPES at LNL, a significant upgrade of the entire setup is currently in progress. The upgrade was funded within the POTLNS project, triggered by the NUMEN physics case [4, 5], in the frame of a national program (PON) aimed at strengthening the research infrastructures identified as priorities, according to the European Strategy Forum on Research Infrastructures (ESFRI). The upgrade consists in a new extraction method based on the stripping of the accelerated ions [6–8] that will be used alternately with the electrostatic deflectors. Such a method is based on the instantaneous change of the magnetic rigidity of the accelerated ions, when their charge state suddenly increases after crossing a thin stripper foil. The final aim is to increase the beam power up to 2–10 kW for ions with mass $A \le 40$ and energy above 15 AMeV. This upper mass limit is connected to the fact that more than 99% of such ions can be fully stripped and therefore extracted from the SC. The reference trajectories for $^{12}$C, $^{18}$O, $^{20}$Ne and $^{40}$Ar are shown in Fig. 5. The feasibility of this kind of extraction through an optimized channel with an increased transverse section has been deeply studied in Refs. [9–11]. In the meantime, the radio-frequency (RF) system has
<figure><img src="image_6.png" /><figcaption>Fig. 4 Highlight for nuclear physics applications for the three lines of research and temporal phases A, B and C</figcaption></figure>

<figure><img src="image_7.png" /><figcaption>Fig. 5 Ion-beam trajectories
calculated for stripping extraction</figcaption></figure>

lower than 60%, and for such a reason, the maximum beam power was limited to about 100 W, constrained by the beam power dissipation on the electrostatic deflectors.

To fulfill the request of users aiming to study rare processes in nuclear physics [4, 5] and provide high-intensity radioactive ion beams, complementary to those delivered by SPES at LNL, a significant upgrade of the entire setup is currently in progress. The upgrade was funded within the POTLNS project, triggered by the NUMEN physics case [4, 5], in the frame of a national program (PON) aimed at strengthening the research infrastructures identified as priorities, according to the European Strategy Forum on Research Infrastructures (ESFRI). The upgrade consists in a new extraction method based on the stripping of the accelerated ions [6–8] that will be used alternately with the electrostatic deflectors. Such a method is based on the instantaneous change of the magnetic rigidity of the accelerated ions, when their charge state suddenly increases after crossing a thin stripper foil. The final aim is to increase the beam power up to 2–10 kW for ions with mass $A \le 40$ and energy above 15 AMeV. This upper mass limit is connected to the fact that more than 99% of such ions can be fully stripped and therefore extracted from the SC. The reference trajectories for $^{12}$C, $^{18}$O, $^{20}$Ne and $^{40}$Ar are shown in Fig. 5. The feasibility of this kind of extraction through an optimized channel with an increased transverse section has been deeply studied in Refs. [9–11]. In the meantime, the radio-frequency (RF) system has
<figure><img src="image_8.png" /><figcaption>**Fig. 6** The upgraded LNS superconducting cyclotron</figcaption></figure>

gone through many improvements for more reliable operation of the SC [12, 13], also increasing to 30 mm the vertical gap between the “dees” of the acceleration chamber, by renewing the existing liners. Other upgrades are under study to further improve the SC performances in terms of intensities and accelerated species.

Figure 6 shows the layout of the new cyclotron, where together with the classical extraction through electrostatic deflection (ED) a second extraction channel has been added, with two further magnetic channels.

Moreover, upgrades of the ion sources and of the axial injection beam line are planned, in order to fully satisfy the requested beam intensity, as well as to optimize the optics and the matching with the SC in the phase space. All these improvements will be performed in the framework of high safety standards for the machine and for the operational staff. The SC recommissioning is foreseen to start in the late 2024 using the electrostatic deflection, while the first extraction by stripping ions is foreseen in the late 2025. Taking profit of the stop for the SC upgrade, also the Tandem is subject to a deep renovation of the hardware, electronics and automation. The power electronics and the diagnostics will be changed, while vacuum and optical element controls will be renewed. An extraordinary maintenance of the Pelletron charge system will be carried out to minimize the ripple and a new Tandem terminal voltage HV stabilizer will be installed. The Tandem has played a crucial role in the framework of nuclear studies as well as cross sections measurements for nuclear astrophysics (see, e.g., Refs. [14, 15]).

## 2.2 Beams

### 2.2.1 High-intensity stable beams

A full list of beams produced so far using the extraction by means of electrostatic deflection is shown in Table 1. Such beams will be always available through the ED extraction channel with a maximum power of about 100 W. Table 2 reports a list of the expected beams and intensities obtained through the new stripping extraction. The availability of new sources (aiming to reach higher charged states and injected currents) and further studies triggered by users’ requests will make it possible to significantly extend such list to other ion species over the years.

A list of the ions accelerated by the LNS Tandem in the last 20 years is shown in Table 3. In addition to those beams, the accelerator division is developing a new source able to provide He beams with this accelerator.

### 2.2.2 FraISe: a new in-flight fragment separator at LNS

In order to exploit the high beam power delivered by the upgraded SC, the POTLNS project has included the construction of a new In-Flight facility for Radioactive Ion Beams (RIBs) production, named Fragment Ion Separator (FraISe) [16–18].

The new FraISe facility will be hosted in a shielded area (bunker), as schematically shown in Fig. 7. It will allow to use primary beams of power up to ~2–3 kW. Figure 8 shows a schematic view of FraISe. The new production target is a copy of the CLIM one used in the LISE facility at GANIL [19]. It will be placed in a dedicated chamber and consists of a beryllium (or carbon) rotating disk of appropriate thickness, allowing to distribute the primary beam power on a circular crown of ~10–15 cm mean radius, allowing to keep the target degradation and heating under control. The beam line upstream the target chamber has been designed with a condition of energy achromatism and a very focused spot size of stable beam at target position, in order to optimize the outgoing cocktail beam.
<figure><img src="image_8.png" /><figcaption>**Fig. 6** The upgraded LNS superconducting cyclotron</figcaption></figure>

gone through many improvements for more reliable operation of the SC [12, 13], also increasing to 30 mm the vertical gap between the “dees” of the acceleration chamber, by renewing the existing liners. Other upgrades are under study to further improve the SC performances in terms of intensities and accelerated species.

Figure 6 shows the layout of the new cyclotron, where together with the classical extraction through electrostatic deflection (ED) a second extraction channel has been added, with two further magnetic channels.

Moreover, upgrades of the ion sources and of the axial injection beam line are planned, in order to fully satisfy the requested beam intensity, as well as to optimize the optics and the matching with the SC in the phase space. All these improvements will be performed in the framework of high safety standards for the machine and for the operational staff. The SC recommissioning is foreseen to start in the late 2024 using the electrostatic deflection, while the first extraction by stripping ions is foreseen in the late 2025. Taking profit of the stop for the SC upgrade, also the Tandem is subject to a deep renovation of the hardware, electronics and automation. The power electronics and the diagnostics will be changed, while vacuum and optical element controls will be renewed. An extraordinary maintenance of the Pelletron charge system will be carried out to minimize the ripple and a new Tandem terminal voltage HV stabilizer will be installed. The Tandem has played a crucial role in the framework of nuclear studies as well as cross sections measurements for nuclear astrophysics (see, e.g., Refs. [14, 15]).

## 2.2 Beams

### 2.2.1 High-intensity stable beams

A full list of beams produced so far using the extraction by means of electrostatic deflection is shown in Table 1. Such beams will be always available through the ED extraction channel with a maximum power of about 100 W. Table 2 reports a list of the expected beams and intensities obtained through the new stripping extraction. The availability of new sources (aiming to reach higher charged states and injected currents) and further studies triggered by users’ requests will make it possible to significantly extend such list to other ion species over the years.

A list of the ions accelerated by the LNS Tandem in the last 20 years is shown in Table 3. In addition to those beams, the accelerator division is developing a new source able to provide He beams with this accelerator.

### 2.2.2 FraISe: a new in-flight fragment separator at LNS

In order to exploit the high beam power delivered by the upgraded SC, the POTLNS project has included the construction of a new In-Flight facility for Radioactive Ion Beams (RIBs) production, named Fragment Ion Separator (FraISe) [16–18].

The new FraISe facility will be hosted in a shielded area (bunker), as schematically shown in Fig. 7. It will allow to use primary beams of power up to ~2–3 kW. Figure 8 shows a schematic view of FraISe. The new production target is a copy of the CLIM one used in the LISE facility at GANIL [19]. It will be placed in a dedicated chamber and consists of a beryllium (or carbon) rotating disk of appropriate thickness, allowing to distribute the primary beam power on a circular crown of ~10–15 cm mean radius, allowing to keep the target degradation and heating under control. The beam line upstream the target chamber has been designed with a condition of energy achromatism and a very focused spot size of stable beam at target position, in order to optimize the outgoing cocktail beam.
<table><caption>**Table 1** The LNS K-800 superconducting cyclotron beams available through electrostatic deflection</caption><thead><tr><th>Ion</th><th>E (A MeV)</th><th>Ion</th><th>E (A MeV)</th></tr></thead><tbody><tr><td>H<sub>2</sub><sup>+</sup></td><td>62, 80</td><td><sup>40</sup>Ar</td><td>15, 20, 40</td></tr><tr><td>H<sub>3</sub><sup>+</sup></td><td>30, 35, 45</td><td><sup>40</sup>Ca</td><td>10, 25, 40, 45</td></tr><tr><td><sup>2</sup>D<sup>+</sup></td><td>35, 62, 80</td><td><sup>42,48</sup>Ca</td><td>10, 45</td></tr><tr><td><sup>4</sup>He</td><td>25, 62, 80</td><td><sup>58</sup>Ni</td><td>16, 23, 25, 30, 35, 40, 45</td></tr><tr><td>He-H</td><td>10, 21</td><td>62, <sup>64</sup>Ni</td><td>25, 35</td></tr><tr><td><sup>9</sup>Be</td><td>45</td><td>68, <sup>70</sup>Zn</td><td>40</td></tr><tr><td><sup>11</sup>B</td><td>55</td><td><sup>74</sup>Ge</td><td>40</td></tr><tr><td><sup>12</sup>C</td><td>23, 62, 80</td><td>78, <sup>86</sup>Kr</td><td>10</td></tr><tr><td><sup>13</sup>C</td><td>45, 55</td><td><sup>84</sup>Kr</td><td>10, 15, 20, 25</td></tr><tr><td><sup>14</sup>N</td><td>62, 80</td><td><sup>93</sup>Nb</td><td>15, 17, 23, 30, 38</td></tr><tr><td><sup>16</sup>O</td><td>21, 25, 55, 62, 80</td><td><sup>107</sup>Ag</td><td>40</td></tr><tr><td><sup>18</sup>O</td><td>15, 55</td><td><sup>112</sup>Sn</td><td>15.5, 35, 43.5</td></tr><tr><td><sup>19</sup>F</td><td>35, 40, 45</td><td><sup>116</sup>Sn</td><td>23, 30, 38</td></tr><tr><td><sup>20</sup>Ne</td><td>20, 40, 45, 62</td><td><sup>124</sup>Sn</td><td>15, 25, 30, 35</td></tr><tr><td><sup>24</sup>Mg</td><td>50</td><td><sup>129</sup>Xe</td><td>20, 21, 23, 35</td></tr><tr><td><sup>27</sup>Al</td><td>40</td><td><sup>197</sup>Au</td><td>10, 15, 20, 21, 23</td></tr><tr><td><sup>36</sup>Ar</td><td>16, 38</td><td><sup>208</sup>Au</td><td>10</td></tr></tbody></table>

<table><caption>**Table 2** The beam current values expected using the stripping extraction from the K-800 superconducting cyclotron</caption><thead><tr><th>Ion</th><th>E (AMeV)</th><th>I<sub>extr</sub> (eµA)</th><th>I<sub>extr</sub> (pps)</th><th>P<sub>extr</sub> (Watt)</th></tr></thead><tbody><tr><td><sup>12</sup>C</td><td>30</td><td>45</td><td>4.7 × 10<sup>13</sup></td><td>2700</td></tr><tr><td><sup>12</sup>C</td><td>45</td><td>90</td><td>9.4 × 10<sup>13</sup></td><td>8100</td></tr><tr><td><sup>12</sup>C</td><td>60</td><td>90</td><td>9.4 × 10<sup>13</sup></td><td>10,800</td></tr><tr><td><sup>18</sup>O</td><td>20</td><td>80</td><td>6.2 × 10<sup>13</sup></td><td>3600</td></tr><tr><td><sup>18</sup>O</td><td>29</td><td>80</td><td>6.2 × 10<sup>13</sup></td><td>5220</td></tr><tr><td><sup>18</sup>O</td><td>45</td><td>80</td><td>6.2 × 10<sup>13</sup></td><td>8100</td></tr><tr><td><sup>18</sup>O</td><td>60</td><td>80</td><td>6.2 × 10<sup>13</sup></td><td>10,800</td></tr><tr><td><sup>18</sup>O</td><td>70</td><td>34</td><td>2.7 × 10<sup>13</sup></td><td>5400</td></tr><tr><td><sup>20</sup>Ne</td><td>28</td><td>85</td><td>5.3 × 10<sup>13</sup></td><td>4800</td></tr><tr><td><sup>20</sup>Ne</td><td>70</td><td>85</td><td>5.3 × 10<sup>13</sup></td><td>10,280</td></tr><tr><td><sup>40</sup>Ar</td><td>60</td><td>77</td><td>2.7 × 10<sup>13</sup></td><td>10,280</td></tr></tbody></table>

<table><caption>**Table 3** Available Tandem beams</caption><tbody><tr><td><sup>1</sup>H, <sup>2</sup>H</td><td><sup>23</sup>Na</td><td><sup>63</sup>Cu, <sup>65</sup>Cu</td></tr><tr><td><sup>6</sup>Li, <sup>7</sup>Li</td><td><sup>24</sup>Mg, <sup>25</sup>Mg</td><td><sup>70</sup>Ge</td></tr><tr><td><sup>9</sup>Be, <sup>10</sup>Be</td><td><sup>27</sup>Al</td><td><sup>79</sup>Br</td></tr><tr><td><sup>10</sup>B, <sup>11</sup>B</td><td><sup>28</sup>Si, <sup>29</sup>Si</td><td><sup>93</sup>Nb</td></tr><tr><td><sup>12</sup>C, <sup>13</sup>C</td><td><sup>32</sup>S, <sup>34</sup>S</td><td><sup>116</sup>Sn</td></tr><tr><td><sup>14</sup>N</td><td><sup>35</sup>Cl, <sup>37</sup>Cl</td><td><sup>120</sup>Sn</td></tr><tr><td><sup>16</sup>O, <sup>17</sup>O, <sup>18</sup>O</td><td><sup>40</sup>Ca</td><td><sup>127</sup>I</td></tr><tr><td><sup>19</sup>F</td><td><sup>58</sup>Ni, <sup>60</sup>Ni</td><td><sup>197</sup>Au</td></tr></tbody></table>

A slit on the symmetry plane can be used to reduce the energetic dispersion of the outgoing beam. The exit slit will be used, when needed, to reduce and possibly remove contaminants from the cocktail beam, thus improving the quality and purity of the produced beams.

The FraISe line will allow to transport beams with a maximum magnetic rigidity of 3.2 Tm. The momentum acceptance is equal to 1.2% and the solid angle acceptance to 2.5 msr. The momentum dispersion at symmetry plane is about 5 m, corresponding to an energy resolving power of about 2600 with 1 mm beam spot size. Given the high energy dispersion capability at the symmetry plane, FraISe will be very effective also in reducing the energy spread of the high-intensity primary beam extracted by the SC using
<table><caption>**Table 1** The LNS K-800 superconducting cyclotron beams available through electrostatic deflection</caption><thead><tr><th>Ion</th><th>E (A MeV)</th><th>Ion</th><th>E (A MeV)</th></tr></thead><tbody><tr><td>H<sub>2</sub><sup>+</sup></td><td>62, 80</td><td><sup>40</sup>Ar</td><td>15, 20, 40</td></tr><tr><td>H<sub>3</sub><sup>+</sup></td><td>30, 35, 45</td><td><sup>40</sup>Ca</td><td>10, 25, 40, 45</td></tr><tr><td><sup>2</sup>D<sup>+</sup></td><td>35, 62, 80</td><td><sup>42,48</sup>Ca</td><td>10, 45</td></tr><tr><td><sup>4</sup>He</td><td>25, 62, 80</td><td><sup>58</sup>Ni</td><td>16, 23, 25, 30, 35, 40, 45</td></tr><tr><td>He-H</td><td>10, 21</td><td>62,<sup>64</sup>Ni</td><td>25, 35</td></tr><tr><td><sup>9</sup>Be</td><td>45</td><td>68,<sup>70</sup>Zn</td><td>40</td></tr><tr><td><sup>11</sup>B</td><td>55</td><td><sup>74</sup>Ge</td><td>40</td></tr><tr><td><sup>12</sup>C</td><td>23, 62, 80</td><td>78,<sup>86</sup>Kr</td><td>10</td></tr><tr><td><sup>13</sup>C</td><td>45, 55</td><td><sup>84</sup>Kr</td><td>10, 15, 20, 25</td></tr><tr><td><sup>14</sup>N</td><td>62, 80</td><td><sup>93</sup>Nb</td><td>15, 17, 23, 30, 38</td></tr><tr><td><sup>16</sup>O</td><td>21, 25, 55, 62, 80</td><td><sup>107</sup>Ag</td><td>40</td></tr><tr><td><sup>18</sup>O</td><td>15, 55</td><td><sup>112</sup>Sn</td><td>15.5, 35, 43.5</td></tr><tr><td><sup>19</sup>F</td><td>35, 40, 45</td><td><sup>116</sup>Sn</td><td>23, 30, 38</td></tr><tr><td><sup>20</sup>Ne</td><td>20, 40, 45, 62</td><td><sup>124</sup>Sn</td><td>15, 25, 30, 35</td></tr><tr><td><sup>24</sup>Mg</td><td>50</td><td><sup>129</sup>Xe</td><td>20, 21, 23, 35</td></tr><tr><td><sup>27</sup>Al</td><td>40</td><td><sup>197</sup>Au</td><td>10, 15, 20, 21, 23</td></tr><tr><td><sup>36</sup>Ar</td><td>16, 38</td><td><sup>208</sup>Au</td><td>10</td></tr></tbody></table>

<table><caption>**Table 2** The beam current values expected using the stripping extraction from the K-800 superconducting cyclotron</caption><thead><tr><th>Ion</th><th>E (AMeV)</th><th>I<sub>extr</sub> (eµA)</th><th>I<sub>extr</sub> (pps)</th><th>P<sub>extr</sub> (Watt)</th></tr></thead><tbody><tr><td><sup>12</sup>C</td><td>30</td><td>45</td><td>4.7 × 10<sup>13</sup></td><td>2700</td></tr><tr><td><sup>12</sup>C</td><td>45</td><td>90</td><td>9.4 × 10<sup>13</sup></td><td>8100</td></tr><tr><td><sup>12</sup>C</td><td>60</td><td>90</td><td>9.4 × 10<sup>13</sup></td><td>10,800</td></tr><tr><td><sup>18</sup>O</td><td>20</td><td>80</td><td>6.2 × 10<sup>13</sup></td><td>3600</td></tr><tr><td><sup>18</sup>O</td><td>29</td><td>80</td><td>6.2 × 10<sup>13</sup></td><td>5220</td></tr><tr><td><sup>18</sup>O</td><td>45</td><td>80</td><td>6.2 × 10<sup>13</sup></td><td>8100</td></tr><tr><td><sup>18</sup>O</td><td>60</td><td>80</td><td>6.2 × 10<sup>13</sup></td><td>10,800</td></tr><tr><td><sup>18</sup>O</td><td>70</td><td>34</td><td>2.7 × 10<sup>13</sup></td><td>5400</td></tr><tr><td><sup>20</sup>Ne</td><td>28</td><td>85</td><td>5.3 × 10<sup>13</sup></td><td>4800</td></tr><tr><td><sup>20</sup>Ne</td><td>70</td><td>85</td><td>5.3 × 10<sup>13</sup></td><td>10,280</td></tr><tr><td><sup>40</sup>Ar</td><td>60</td><td>77</td><td>2.7 × 10<sup>13</sup></td><td>10,280</td></tr></tbody></table>

<table><caption>**Table 3** Available Tandem beams</caption><tbody><tr><td><sup>1</sup>H, <sup>2</sup>H</td><td><sup>23</sup>Na</td><td><sup>63</sup>Cu, <sup>65</sup>Cu</td></tr><tr><td><sup>6</sup>Li, <sup>7</sup>Li</td><td><sup>24</sup>Mg, <sup>25</sup>Mg</td><td><sup>70</sup>Ge</td></tr><tr><td><sup>9</sup>Be, <sup>10</sup>Be</td><td><sup>27</sup>Al</td><td><sup>79</sup>Br</td></tr><tr><td><sup>10</sup>B, <sup>11</sup>B</td><td><sup>28</sup>Si, <sup>29</sup>Si</td><td><sup>93</sup>Nb</td></tr><tr><td><sup>12</sup>C, <sup>13</sup>C</td><td><sup>32</sup>S, <sup>34</sup>S</td><td><sup>116</sup>Sn</td></tr><tr><td><sup>14</sup>N</td><td><sup>35</sup>Cl, <sup>37</sup>Cl</td><td><sup>120</sup>Sn</td></tr><tr><td><sup>16</sup>O, <sup>17</sup>O, <sup>18</sup>O</td><td><sup>40</sup>Ca</td><td><sup>127</sup>I</td></tr><tr><td><sup>19</sup>F</td><td><sup>58</sup>Ni, <sup>60</sup>Ni</td><td><sup>197</sup>Au</td></tr></tbody></table>

A slit on the symmetry plane can be used to reduce the energetic dispersion of the outgoing beam. The exit slit will be used, when needed, to reduce and possibly remove contaminants from the cocktail beam, thus improving the quality and purity of the produced beams.

The FraISe line will allow to transport beams with a maximum magnetic rigidity of 3.2 Tm. The momentum acceptance is equal to 1.2% and the solid angle acceptance to 2.5 msr. The momentum dispersion at symmetry plane is about 5 m, corresponding to an energy resolving power of about 2600 with 1 mm beam spot size. Given the high energy dispersion capability at the symmetry plane, FraISe will be very effective also in reducing the energy spread of the high-intensity primary beam extracted by the SC using
<figure><img src="image_9.png" /><figcaption>Fig. 7 Schematic view of the LNS following the POTLNS upgrade project</figcaption></figure>

<figure><img src="image_10.png" /><figcaption>Fig. 8 Schematic view of the FraISe fragment separator</figcaption></figure>

the stripping method. These features will allow to use FraISe not only as in-flight facility, but also as a precise energy selector for those experiments requiring stable beams with very small energy dispersion. For example, it will be possible to reach an energy spread of 0.1%, a value which matches one of the mandatory constraints for the NUMEN experimental program [20].
<figure><img src="image_9.png" /><figcaption>Fig. 7 Schematic view of the LNS following the POTLNS upgrade project</figcaption></figure>

<figure><img src="image_10.png" /><figcaption>Fig. 8 Schematic view of the FraISe fragment separator</figcaption></figure>

the stripping method. These features will allow to use FraISe not only as in-flight facility, but also as a precise energy selector for those experiments requiring stable beams with very small energy dispersion. For example, it will be possible to reach an energy spread of 0.1%, a value which matches one of the mandatory constraints for the NUMEN experimental program [20].
<figure><img src="image_11.png" /><figcaption>**Fig. 9** Estimation of isotopes yield and average energy, at the exit of the fragment separator, achievable with FraISe using primary beams of ¹²C at 60 AMeV (left panel) and ¹⁸O at 70 AMeV (right panel)</figcaption></figure>

<caption>**Fig. 10** Same as Fig. 9 but using a primary beam of ²⁰Ne at 70 AMeV</caption>

<table><caption>²⁰Ne¹⁰⁺ @70 MeV/A 2 kW on ⁹Be target</caption><thead><tr><th>¹⁷Ne</th><th>¹⁸Ne</th><th>¹⁹Ne</th><th>²⁰Ne</th><th>²¹Ne</th><th>²²Ne</th><th>²³Ne</th><th>²⁴Ne</th></tr></thead><tbody><tr><td>8.7E5<br>53</td><td>3.1E7<br>51</td><td>6.0E8<br>52</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td></td><td>17F<br>1.7E8<br>50</td><td>18F</td><td>19F</td><td>20F<br>9.5E6<br>55</td><td>21F</td><td>22F</td><td>23F</td></tr><tr><td>¹⁵O</td><td>¹⁶O</td><td>¹⁷O</td><td>¹⁸O</td><td>¹⁹O</td><td>²⁰O</td><td>²¹O</td><td>²²O</td></tr><tr><td>¹⁴N</td><td>¹⁵N</td><td>¹⁶N</td><td>¹⁷N</td><td>¹⁸N<br>3.7E6<br>57</td><td>¹⁹N</td><td>²⁰N</td><td>²¹N</td></tr></tbody></table>

An aluminum degrader can be placed close to the symmetry plane after the central slit, in order to modify the magnetic rigidity of species with similar A/Z ratio and perform a better rejection of contaminants.

Sizeable improvements in the yield production of light and medium mass exotic nuclei in the Fermi energy regime are foreseen due to the higher power of the primary beams following the SC upgrade. In order to present a few examples of the potentialities of the new fragment separator, simulations of RIBs production were carried out using the LISE++ tool [21] for few relevant cases. In these simulations, a 100-µm-thick aluminum degrader was placed on the symmetry plane, and a 100-µm-thick SiC detector (presently under test) at the exit of the fragment separator as tagging detector. The results have been obtained assuming 2 kW primary beams for the ions listed in Table 2, but only for a single beam energy. Thus, the same primary beams, but at different energies, can be used while keeping in mind that below $E_{beam} = 25$ AMeV the fragmentation becomes less effective in producing RIBs of sufficient intensities.

For each isotope of interest, a ⁹Be production target was used with optimized thickness and the fragment separator was tuned in order to allow a good separation from the contaminants. To this aim, a ΔE-ToF tagging plot was simulated, where the ΔE is given by the energy deposited in the SiC detector and the ToF is the time difference between the radio-frequency signal of the SC and the timing signal of the SiC detector (with expected time resolution better than 500 ps). Figure 9 reports the expected intensities and average energies for RIBs produced by ¹²C⁶⁺ at 60 AMeV (left panel) and ¹⁸O⁸⁺ at 70 AMeV primary beams (right panel). Results indicate that about 10⁷–10⁸ pps can be reached for RIBs near the primary beams and the stability valley while yield production for nuclei far from stability valley can reach about 10³–10⁴ pps. Figure 10 shows the simulated yield production using a primary beam of ²⁰Ne¹⁰⁺ at 70 AMeV.

To evaluate the potentially achievable beam purity, the spatial distribution at the exit of the fragment separator on the horizontal direction and the ΔE-ToF tagging plot with ¹⁸O⁸⁺ at 70 AMeV as primary beam, with the fragment separator optimized for ¹⁶C
<figure><img src="image_11.png" /><figcaption>**Fig. 9** Estimation of isotopes yield and average energy, at the exit of the fragment separator, achievable with FraISe using primary beams of $^{12}\text{C}$ at 60 AMeV (left panel) and $^{18}\text{O}$ at 70 AMeV (right panel)</figcaption></figure>

<caption>**Fig. 10** Same as Fig. 9 but using a primary beam of $^{20}\text{Ne}$ at 70 AMeV</caption>

<table><caption>$^{20}\text{Ne}^{10+}$ @70 MeV/A 2 kW on $^{9}\text{Be}$ target</caption><thead><tr><th><sup>17</sup>Ne</th><th><sup>18</sup>Ne</th><th><sup>19</sup>Ne</th><th><sup>20</sup>Ne</th><th><sup>21</sup>Ne</th><th><sup>22</sup>Ne</th><th><sup>23</sup>Ne</th><th><sup>24</sup>Ne</th></tr></thead><tbody><tr><td>8.7E5<br>53</td><td>3.1E7<br>51</td><td>6.0E8<br>52</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td></td><td>17F<br>1.7E8<br>50</td><td>18F</td><td>19F</td><td>20F<br>9.5E6<br>55</td><td>21F</td><td>22F</td><td>23F</td></tr><tr><td><sup>15</sup>O</td><td><sup>16</sup>O</td><td><sup>17</sup>O</td><td><sup>18</sup>O</td><td><sup>19</sup>O</td><td><sup>20</sup>O</td><td><sup>21</sup>O</td><td><sup>22</sup>O</td></tr><tr><td><sup>14</sup>N</td><td><sup>15</sup>N</td><td><sup>16</sup>N</td><td><sup>17</sup>N</td><td><sup>18</sup>N<br>3.7E6<br>57</td><td><sup>19</sup>N</td><td><sup>20</sup>N</td><td><sup>21</sup>N</td></tr></tbody></table>

An aluminum degrader can be placed close to the symmetry plane after the central slit, in order to modify the magnetic rigidity of species with similar A/Z ratio and perform a better rejection of contaminants.

Sizeable improvements in the yield production of light and medium mass exotic nuclei in the Fermi energy regime are foreseen due to the higher power of the primary beams following the SC upgrade. In order to present a few examples of the potentialities of the new fragment separator, simulations of RIBs production were carried out using the LISE++ tool [21] for few relevant cases. In these simulations, a 100-µm-thick aluminum degrader was placed on the symmetry plane, and a 100-µm-thick SiC detector (presently under test) at the exit of the fragment separator as tagging detector. The results have been obtained assuming 2 kW primary beams for the ions listed in Table 2, but only for a single beam energy. Thus, the same primary beams, but at different energies, can be used while keeping in mind that below $E_{\text{beam}} = 25$ AMeV the fragmentation becomes less effective in producing RIBs of sufficient intensities.

For each isotope of interest, a $^{9}\text{Be}$ production target was used with optimized thickness and the fragment separator was tuned in order to allow a good separation from the contaminants. To this aim, a $\Delta E$-ToF tagging plot was simulated, where the $\Delta E$ is given by the energy deposited in the SiC detector and the ToF is the time difference between the radio-frequency signal of the SC and the timing signal of the SiC detector (with expected time resolution better than 500 ps). Figure 9 reports the expected intensities and average energies for RIBs produced by $^{12}\text{C}^{6+}$ at 60 AMeV (left panel) and $^{18}\text{O}^{8+}$ at 70 AMeV primary beams (right panel). Results indicate that about $10^{7}-10^{8}$ pps can be reached for RIBs near the primary beams and the stability valley while yield production for nuclei far from stability valley can reach about $10^{3}-10^{4}$ pps. Figure 10 shows the simulated yield production using a primary beam of $^{20}\text{Ne}^{10+}$ at 70 AMeV.

To evaluate the potentially achievable beam purity, the spatial distribution at the exit of the fragment separator on the horizontal direction and the $\Delta E$-ToF tagging plot with $^{18}\text{O}^{8+}$ at 70 AMeV as primary beam, with the fragment separator optimized for $^{16}\text{C}$
<figure><img src="image_12.png" /><figcaption>$^{40}$Ar$^{18+}$ @60 MeV/A 2 kW on $^{9}$Be target</figcaption></figure>

<table><caption>**Fig. 12** Same as Figs. 9 and 10 but using a primary beam of $^{40}$Ar at 60 AMeV</caption><thead><tr><th></th><th></th><th></th><th></th><th>3<sup>5</sup>K</th><th>3<sup>6</sup>K</th><th>3<sup>7</sup>K</th><th>3<sup>8</sup>K</th><th>3<sup>9</sup>K</th><th>4<sup>0</sup>K</th><th>4<sup>1</sup>K</th><th>4<sup>2</sup>K</th><th>4<sup>3</sup>K</th></tr></thead><tbody><tr><td></td><td></td><td>3<sup>1</sup>Ar</td><td>3<sup>2</sup>Ar</td><td>3<sup>3</sup>Ar</td><td>3<sup>4</sup>Ar</td><td>3<sup>5</sup>Ar</td><td>3<sup>6</sup>Ar</td><td>3<sup>7</sup>Ar</td><td>3<sup>8</sup>Ar</td><td>3<sup>9</sup>Ar</td><td>4<sup>0</sup>Ar</td><td>4<sup>1</sup>Ar</td><td>4<sup>2</sup>Ar</td></tr><tr><td></td><td></td><td></td><td></td><td></td><td></td><td>8.9E5</td><td>9.2E7</td><td>42</td><td></td><td>1.3E9</td><td></td><td>1.0E7</td><td>2.2e4</td></tr><tr><td></td><td></td><td></td><td>3<sup>1</sup>Cl</td><td>3<sup>2</sup>Cl</td><td>3<sup>3</sup>Cl</td><td>3<sup>4</sup>Cl</td><td>3<sup>5</sup>Cl</td><td>3<sup>6</sup>Cl</td><td>3<sup>7</sup>Cl</td><td>3<sup>8</sup>Cl</td><td>3<sup>9</sup>Cl</td><td>4<sup>0</sup>Cl</td><td>4<sup>1</sup>Cl</td></tr><tr><td></td><td></td><td></td><td></td><td>4.6E4</td><td>1.2E6</td><td>1.5E7</td><td>42</td><td></td><td></td><td>7.4E8</td><td>3.2E8</td><td>4.9E6</td><td>4.8E3</td></tr><tr><td></td><td></td><td></td><td></td><td>46</td><td>46</td><td></td><td></td><td></td><td></td><td>39</td><td>44</td><td>44</td><td>46</td></tr><tr><td>28S</td><td>29S</td><td>30S</td><td>31S</td><td>32S</td><td>33S</td><td>34S</td><td>35S</td><td>36S</td><td>37S</td><td>38S</td><td>39S</td><td>40S</td></tr><tr><td></td><td></td><td>5.7E4</td><td>3.5E7</td><td></td><td></td><td></td><td>1.1E8</td><td></td><td></td><td>6.1E7</td><td>1.7E7</td><td>1.6E5</td><td>4.1E2</td></tr><tr><td></td><td></td><td>42</td><td>45</td><td></td><td></td><td></td><td>35</td><td></td><td></td><td>48</td><td>48</td><td>47</td><td>49</td></tr><tr><td>27p</td><td>28p</td><td>5.8E4</td><td>1.3E6</td><td>31p</td><td>32p</td><td>33p</td><td>34p</td><td>35p</td><td>36p</td><td>37p</td><td>38p</td><td>39p</td></tr><tr><td></td><td></td><td>42</td><td>43</td><td></td><td>9.2E7</td><td>6.7E7</td><td>3.9E7</td><td>1.5E7</td><td></td><td>8.2E5</td><td>7.9E3</td><td>48</td><td></td></tr><tr><td></td><td></td><td></td><td></td><td></td><td>44</td><td>48</td><td>44</td><td>48</td><td></td><td>50</td><td></td><td></td><td></td></tr><tr><td>26Si</td><td>27Si</td><td>9.7E5</td><td>43</td><td>30S</td><td>31Si</td><td>32Si</td><td>33Si</td><td>34Si</td><td>35Si</td><td>36Si</td><td>37Si</td><td>38Si</td></tr><tr><td></td><td></td><td></td><td></td><td></td><td>3.5E7</td><td>1.3E7</td><td>3.5E6</td><td>52</td><td>1.0E6</td><td>1.9E5</td><td>2.5E4</td><td></td><td></td></tr><tr><td></td><td></td><td></td><td></td><td></td><td>45</td><td>48</td><td>52</td><td>52</td><td>52</td><td>49</td><td>49</td><td></td><td></td></tr><tr><td>25Al</td><td>26Al</td><td>5.4E6</td><td>44</td><td>27Al</td><td>28Al</td><td>29Al</td><td>30Al</td><td>31Al</td><td>32Al</td><td>33Al</td><td>34Al</td><td>35Al</td><td>36Al</td></tr><tr><td></td><td></td><td>44</td><td>44</td><td></td><td>2.0E7</td><td>1.2E7</td><td>4.4E6</td><td>1.0E6</td><td>2.1E5</td><td>3.1E4</td><td>4.3E3</td><td>5.0E2</td><td>4.9</td></tr><tr><td></td><td></td><td></td><td></td><td></td><td>45</td><td>45</td><td>45</td><td>52</td><td>45</td><td>52</td><td>52</td><td>52</td><td>51</td></tr></tbody></table>

production, were simulated. Results are shown in Fig. 11. The spatial separation with respect to the main contaminants on the plane of the slits is wide enough to ensure a high-purity $^{16}$C beam. Moreover, using primary beams of ~30 AMeV will result in a decrease,
<figure><img src="image_12.png" /><figcaption>$^{40}$Ar$^{18+}$ @60 MeV/A 2 kW on $^{9}$Be target</figcaption></figure>

<table><caption>**Fig. 12** Same as Figs. 9 and 10 but using a primary beam of $^{40}$Ar at 60 AMeV</caption><thead><tr><th></th><th></th><th></th><th></th><th>3<sup>5</sup>K</th><th>3<sup>6</sup>K</th><th>3<sup>7</sup>K</th><th>3<sup>8</sup>K</th><th>3<sup>9</sup>K</th><th>4<sup>0</sup>K</th><th>4<sup>1</sup>K</th><th>4<sup>2</sup>K</th><th>4<sup>3</sup>K</th></tr></thead><tbody><tr><td></td><td><sup>31</sup>Ar</td><td><sup>32</sup>Ar</td><td><sup>33</sup>Ar</td><td><sup>34</sup>Ar</td><td><sup>35</sup>Ar</td><td><sup>36</sup>Ar</td><td><sup>37</sup>Ar</td><td><sup>38</sup>Ar</td><td><sup>39</sup>Ar</td><td><sup>40</sup>Ar</td><td><sup>41</sup>Ar</td><td><sup>42</sup>Ar</td></tr><tr><td></td><td></td><td></td><td></td><td></td><td>8.9E5</td><td>45</td><td>9.2E7</td><td>42</td><td>1.3E9</td><td>43</td><td>1.0E7</td><td>47</td></tr><tr><td></td><td></td><td><sup>31</sup>Cl</td><td><sup>32</sup>Cl</td><td><sup>33</sup>Cl</td><td><sup>34</sup>Cl</td><td><sup>35</sup>Cl</td><td><sup>36</sup>Cl</td><td><sup>37</sup>Cl</td><td><sup>38</sup>Cl</td><td><sup>39</sup>Cl</td><td><sup>40</sup>Cl</td><td><sup>41</sup>Cl</td></tr><tr><td></td><td></td><td></td><td>4.6E4</td><td>1.2E6</td><td>1.5E7</td><td>42</td><td></td><td></td><td>7.4E8</td><td>3.2E8</td><td>4.9E6</td><td>4.8E3</td></tr><tr><td><sup>28</sup>S</td><td><sup>29</sup>S</td><td><sup>30</sup>S</td><td><sup>31</sup>S</td><td><sup>32</sup>S</td><td><sup>33</sup>S</td><td><sup>34</sup>S</td><td><sup>35</sup>S</td><td><sup>36</sup>S</td><td><sup>37</sup>S</td><td><sup>38</sup>S</td><td><sup>39</sup>S</td><td><sup>40</sup>S</td></tr><tr><td></td><td></td><td>5.7E4</td><td>3.5E7</td><td></td><td></td><td></td><td>1.1E8</td><td></td><td>6.1E7</td><td>48</td><td>1.6E5</td><td>47</td></tr><tr><td></td><td></td><td></td><td>42</td><td>45</td><td></td><td></td><td>35</td><td></td><td></td><td></td><td></td><td>49</td></tr><tr><td><sup>27</sup>p</td><td><sup>28</sup>p</td><td><sup>29</sup>p</td><td><sup>30</sup>p</td><td><sup>31</sup>p</td><td><sup>32</sup>p</td><td><sup>33</sup>p</td><td><sup>34</sup>p</td><td><sup>35</sup>p</td><td><sup>36</sup>p</td><td><sup>37</sup>p</td><td><sup>38</sup>p</td><td><sup>39</sup>p</td></tr><tr><td></td><td>5.8E4</td><td>1.3E6</td><td>1.1E7</td><td></td><td>9.2E7</td><td>6.7E7</td><td>3.9E7</td><td>1.5E7</td><td></td><td>8.2E5</td><td>7.9E3</td><td></td></tr><tr><td></td><td></td><td>42</td><td>43</td><td></td><td>44</td><td>48</td><td>44</td><td>48</td><td></td><td>50</td><td>48</td><td></td></tr><tr><td><sup>26</sup>Si</td><td><sup>27</sup>Si</td><td><sup>28</sup>Si</td><td><sup>29</sup>Si</td><td><sup>30</sup>S</td><td><sup>31</sup>Si</td><td><sup>32</sup>Si</td><td><sup>33</sup>Si</td><td><sup>34</sup>Si</td><td><sup>35</sup>Si</td><td><sup>36</sup>Si</td><td><sup>37</sup>Si</td><td><sup>38</sup>Si</td></tr><tr><td></td><td></td><td>9.7E5</td><td>43</td><td></td><td>3.5E7</td><td>1.3E7</td><td>3.5E6</td><td>52</td><td>1.0E6</td><td>1.9E5</td><td>2.5E4</td><td></td></tr><tr><td><sup>25</sup>Al</td><td><sup>26</sup>Al</td><td><sup>27</sup>Al</td><td><sup>28</sup>Al</td><td><sup>29</sup>Al</td><td><sup>30</sup>Al</td><td><sup>31</sup>Al</td><td><sup>32</sup>Al</td><td><sup>33</sup>Al</td><td><sup>34</sup>Al</td><td><sup>35</sup>Al</td><td><sup>36</sup>Al</td><td><sup>37</sup>Al</td></tr><tr><td></td><td>9.2E5</td><td>5.4E6</td><td></td><td>2.0E7</td><td>1.2E7</td><td>4.4E6</td><td>1.0E6</td><td>2.1E5</td><td>3.1E4</td><td>4.3E3</td><td>5.0E2</td><td>4.9</td></tr><tr><td></td><td>44</td><td>44</td><td></td><td>45</td><td>45</td><td>45</td><td>52</td><td>45</td><td>52</td><td>52</td><td>52</td><td>51</td></tr></tbody></table>

production, were simulated. Results are shown in Fig. 11. The spatial separation with respect to the main contaminants on the plane of the slits is wide enough to ensure a high-purity $^{16}$C beam. Moreover, using primary beams of ~ 30 AMeV will result in a decrease,
**Fig. 13** Experimental setup in the CT2000 chamber to perform an experiment of relevance for nuclear astrophysics. The two movable arms where detectors are mounted are clearly visible, together with the target holder and the last part of the beam pipe

<figure><img src="image_13.png" /></figure>

with respect to the case of ~ 70 AMeV, of ~ 1 order of magnitude for the expected intensities and final energies of 20–25 AMeV. Exploiting these light primary beams, it will be possible to efficiently span a relevant part of neutron-poor and neutron-rich unstable nuclei with $A \le 20$. Figure 12 presents the results obtained using a primary beam of $^{40}$Ar$^{18+}$ at 60 AMeV showing the wide spectrum of exotic isotopes of K, Ar, Cl, S, P, Si and Al that can be produced.

The use of other primary beams is possible, but it requires a special study devoted to investigate the acceleration and extraction trajectories inside the SC and the achievable output power. Further beams would allow to extend the already rich presented offer, and to investigate several physics cases of relevant interest. Possible examples are represented by the $^{13}$C primary beam which would allow to increase the yield of neutron-rich B, Be, Li isotopes and by the $^{16}$O which would allow to increase the yield of neutron-poor oxygen isotopes, with respect to what shown in Figs. 9 and 10. The $^{22}$Ne primary beam could be used to increase the yield of neutron-rich N, O, F isotopes, while the $^{36}$Ar beam is suited for a better production of neutron-poor isotopes. In addition, the use of heavier primary beams, such as Ni or Zn, could be also relevant for producing heavier isotopes and will be investigated in a near future, following the detailed characterization of the SC that will take place during the commissioning phase.

Thus, the availability of the RIBs offered by FraISE will be very competitive, in the international scenario, for light and medium mass nuclei at the Fermi energies. This will be complementary to what made available by the SPES facility [22], offering heavier beams at lower beam energies. The operation of both facilities in Italy will be very important for the nuclear physics community.

## 2.3 Facilities at LNS: present and future scenario

Keeping in with the main scientific mission of the LNS related to the study of fundamental nuclear physics, the LNS hosts several facilities and more are about to come. A brief overview will follow, starting from the existing ones and then moving on to outline the future scenario.

* **Multipurpose scattering chambers: CT2000 and GIRA:** the LNS have traditionally provided the users with the CT2000 scattering chamber, placed at the end of the 60 degree beam line, available for experiments with Tandem beams. The chamber, with a diameter of 2 m, is equipped with 2 independently rotating arms to host the detectors and a collimation system with a goniometer that allows to measure precise angular distributions. The interior of CT2000 is shown in Fig. 13. The CICLOPE chamber, devoted to experiments with cyclotron beams, will be soon replaced with a smaller cylindrical chamber, called GIRA, with a diameter of 1.5 m and a length of 2 m, still reliable for complex detection systems with hundreds of detectors.
Multipurpose chambers have been used to perform experiments of nuclear physics and nuclear astrophysics, covering several topics such as the equation of state of nuclear matter and the role of symmetry energy, the influence and role of isospin and clustering, the stellar and primordial nucleosynthesis and energetics by means of the Trojan horse method and the asymptotic normalization coefficient.

* **CHIMERA:** it is a $4\pi$ multidetector operating at LNS for about 20 years (see, for instance, Ref. [23] and Fig. 14). It is equipped with 1192 detection units, each consisting of a silicon first stage detector, followed by CsI(Tl) crystal coupled to a photodiode as second stage. Different particle identification methods are in operation ($\Delta$E–E, time of flight, pulse shape discrimination) for a complete detection of the charged particles emitted in nuclear collisions. Furthermore, the CsI(Tl) crystals can be used to detect and identify neutrons (by shadowing or vetoing the charged particle produced) and $\gamma$-rays.
CHIMERA will be coupled with the FARCOS [24] (Femtoscope ARray for COrrelations and Spectroscopy) correlator devoted to high angular and energy resolution particle-particle correlation studies. In its complete configuration, FARCOS will consist of 20 modules, each one made of two stages of double-sided silicon strip detectors (DSSSD) with thickness of 300 and 1500 $\mu$m, respectively, and a third stage with a CsI(Tl) crystal+Si photodiode for a total of 132 detection channels. In future, an ancillary hodoscope for $n, \gamma$ and charged particles will be also added. Feasibility studies are currently underway on an EJ-276G + SiPM prototype. Future CHIMERA experimental activity will be performed with the new high-intensity stable SC beams (see Sect. 2 and Table 2) as well as FraISe radioactive beams (see Sect. 2.2.2 and Figs. 9 and 10).
**Fig. 13** Experimental setup in the CT2000 chamber to perform an experiment of relevance for nuclear astrophysics. The two movable arms where detectors are mounted are clearly visible, together with the target holder and the last part of the beam pipe

<figure><img src="image_13.png" /></figure>

with respect to the case of ~ 70 AMeV, of ~ 1 order of magnitude for the expected intensities and final energies of 20–25 AMeV. Exploiting these light primary beams, it will be possible to efficiently span a relevant part of neutron-poor and neutron-rich unstable nuclei with $A \le 20$. Figure 12 presents the results obtained using a primary beam of $^{40}$Ar$^{18+}$ at 60 AMeV showing the wide spectrum of exotic isotopes of K, Ar, Cl, S, P, Si and Al that can be produced.

The use of other primary beams is possible, but it requires a special study devoted to investigate the acceleration and extraction trajectories inside the SC and the achievable output power. Further beams would allow to extend the already rich presented offer, and to investigate several physics cases of relevant interest. Possible examples are represented by the $^{13}$C primary beam which would allow to increase the yield of neutron-rich B, Be, Li isotopes and by the $^{16}$O which would allow to increase the yield of neutron-poor oxygen isotopes, with respect to what shown in Figs. 9 and 10. The $^{22}$Ne primary beam could be used to increase the yield of neutron-rich N, O, F isotopes, while the $^{36}$Ar beam is suited for a better production of neutron-poor isotopes. In addition, the use of heavier primary beams, such as Ni or Zn, could be also relevant for producing heavier isotopes and will be investigated in a near future, following the detailed characterization of the SC that will take place during the commissioning phase.

Thus, the availability of the RIBs offered by FraISE will be very competitive, in the international scenario, for light and medium mass nuclei at the Fermi energies. This will be complementary to what made available by the SPES facility [22], offering heavier beams at lower beam energies. The operation of both facilities in Italy will be very important for the nuclear physics community.

## 2.3 Facilities at LNS: present and future scenario

Keeping in with the main scientific mission of the LNS related to the study of fundamental nuclear physics, the LNS hosts several facilities and more are about to come. A brief overview will follow, starting from the existing ones and then moving on to outline the future scenario.

* **Multipurpose scattering chambers: CT2000 and GIRA:** the LNS have traditionally provided the users with the CT2000 scattering chamber, placed at the end of the 60 degree beam line, available for experiments with Tandem beams. The chamber, with a diameter of 2 m, is equipped with 2 independently rotating arms to host the detectors and a collimation system with a goniometer that allows to measure precise angular distributions. The interior of CT2000 is shown in Fig. 13. The CICLOPE chamber, devoted to experiments with cyclotron beams, will be soon replaced with a smaller cylindrical chamber, called GIRA, with a diameter of 1.5 m and a length of 2 m, still reliable for complex detection systems with hundreds of detectors. Multipurpose chambers have been used to perform experiments of nuclear physics and nuclear astrophysics, covering several topics such as the equation of state of nuclear matter and the role of symmetry energy, the influence and role of isospin and clustering, the stellar and primordial nucleosynthesis and energetics by means of the Trojan horse method and the asymptotic normalization coefficient.

* **CHIMERA:** it is a $4\pi$ multidetector operating at LNS for about 20 years (see, for instance, Ref. [23] and Fig. 14). It is equipped with 1192 detection units, each consisting of a silicon first stage detector, followed by CsI(Tl) crystal coupled to a photodiode as second stage. Different particle identification methods are in operation ($\Delta$E-E, time of flight, pulse shape discrimination) for a complete detection of the charged particles emitted in nuclear collisions. Furthermore, the CsI(Tl) crystals can be used to detect and identify neutrons (by shadowing or vetoing the charged particle produced) and $\gamma$-rays.

CHIMERA will be coupled with the FARCOS [24] (Femtoscope ARray for COrrelations and Spectroscopy) correlator devoted to high angular and energy resolution particle-particle correlation studies. In its complete configuration, FARCOS will consist of 20 modules, each one made of two stages of double-sided silicon strip detectors (DSSSD) with thickness of 300 and 1500 $\mu$m, respectively, and a third stage with a CsI(Tl) crystal+Si photodiode for a total of 132 detection channels. In future, an ancillary hodoscope for $n, \gamma$ and charged particles will be also added. Feasibility studies are currently underway on an EJ-276G + SiPM prototype. Future CHIMERA experimental activity will be performed with the new high-intensity stable SC beams (see Sect. 2 and Table 2) as well as FraISe radioactive beams (see Sect. 2.2.2 and Figs. 9 and 10).
<figure><img src="image_14.png" /><figcaption>**Fig. 15** The future MAGNEX configurations: red writings with arrows highlight the parts that are currently being upgraded/refurbished</figcaption></figure>

<figure><img src="image_15.png" /></figure>

* MAGNEX: it is a large acceptance magnetic spectrometer (see Fig. 15) that combines the advantages of traditional magnetic spectrometry with those of a large angular (50 msr) and momentum (−14%, + 10.3%) acceptance detector [25]. The spectrometer consists of two large aperture magnets, i.e., a quadrupole followed by a 55° dipole and a focal plane detector (FPD) for detecting the ions emitted during a reaction. The quadrupole magnet focuses in the non-dispersive (vertical) direction, while the dipole magnet provides the dispersion and the focusing strength in the dispersive direction (horizontal). Two ancillary surface coils are used to fine-tune and adapt the focusing to the kinematics of the reaction under study (α coil) and to correct for chromatic aberrations (β coil). The accepted magnetic rigidities, Bρ, range from ~ 0.2 Tm to ~ 1.8 Tm, corresponding to energies of the detected ions ranging from E ~ 0.2 AMeV to E ~ 40 AMeV, depending on their mass and charge. An intense activity is currently in progress for the upgrade of MAGNEX to withstand the forthcoming high rates (Table 2), while maintaining the current resolution and sensitivity. In particular, this upgrade will include [26]: a new power supply to increase the maximum magnetic rigidity acceptance from 1.8 to 2.2 Tm, resulting in an increase of the energy range of detected particles; a new focal plane detector (FPD), consisting of a gas tracker based on M-THGEM technology and a wall of telescopes of SiC-CsI detectors for ion identification (PID wall); a gamma-array calorimeter of LaBr (G-NUMEN); the development of suitable front-end and readout electronics, for a fast readout of the detector signals, a high signal-to-noise ratio and adequate hardness to radiation; the implementation of a suitable architecture for data acquisition, storage and data handling; the development of the technology for nuclear targets to be used in the future experiments; and a new beam dump in the MAGNEX hall to stop the high power beams.
<figure><img src="image_14.png" /><figcaption>**Fig. 15** The future MAGNEX configurations: red writings with arrows highlight the parts that are currently being upgraded/refurbished</figcaption></figure>

<figure><img src="image_15.png" /></figure>

* MAGNEX: it is a large acceptance magnetic spectrometer (see Fig. 15) that combines the advantages of traditional magnetic spectrometry with those of a large angular (50 msr) and momentum (−14%, + 10.3%) acceptance detector [25]. The spectrometer consists of two large aperture magnets, i.e., a quadrupole followed by a 55° dipole and a focal plane detector (FPD) for detecting the ions emitted during a reaction. The quadrupole magnet focuses in the non-dispersive (vertical) direction, while the dipole magnet provides the dispersion and the focusing strength in the dispersive direction (horizontal). Two ancillary surface coils are used to fine-tune and adapt the focusing to the kinematics of the reaction under study (α coil) and to correct for chromatic aberrations (β coil). The accepted magnetic rigidities, Bρ, range from ~ 0.2 Tm to ~ 1.8 Tm, corresponding to energies of the detected ions ranging from E ~ 0.2 AMeV to E ~ 40 AMeV, depending on their mass and charge. An intense activity is currently in progress for the upgrade of MAGNEX to withstand the forthcoming high rates (Table 2), while maintaining the current resolution and sensitivity. In particular, this upgrade will include [26]: a new power supply to increase the maximum magnetic rigidity acceptance from 1.8 to 2.2 Tm, resulting in an increase of the energy range of detected particles; a new focal plane detector (FPD), consisting of a gas tracker based on M-THGEM technology and a wall of telescopes of SiC-CsI detectors for ion identification (PID wall); a gamma-array calorimeter of LaBr (G-NUMEN); the development of suitable front-end and readout electronics, for a fast readout of the detector signals, a high signal-to-noise ratio and adequate hardness to radiation; the implementation of a suitable architecture for data acquisition, storage and data handling; the development of the technology for nuclear targets to be used in the future experiments; and a new beam dump in the MAGNEX hall to stop the high power beams.
* **PANDORA**: it will be a facility [27] conceived for multidisciplinary studies especially in the nuclear astrophysics framework. The main objective is to perform the first measurements of β-decays of astrophysical relevance in laboratory magnetized plasmas able to mimic some stellar-like conditions. The new experimental approach will allow to check the theoretical predictions about decay rates variation (expected to change dramatically as a function of the ionization state [28]). Only few experimental evidences were, in fact, collected up to now in storage rings (e.g., a lifetime reduction by 9 orders of magnitude was measured for $^{187}$Re [29]). Another relevant goal is to measure the opacities of plasmas of astrophysical interest (kilonovae's ejecta). PANDORA will mainly consist of three subsystems:

- an innovative superconducting magnetic plasma trap [30], capable to produce and confine plasmas with electron-ion densities up to $10^{13} \text{ cm}^{-3}$ and electron temperatures of $T_e \sim 0.1–30 \text{ keV}$;

- an advanced plasma multidiagnostic system [31], consisting of a set of noninvasive diagnostic tools capable of operating simultaneously for the non-intrusive monitoring of the thermodynamic plasma properties and the measurement of plasma parameters;

- an array of 14 HPGe (high-purity germanium) detectors for γ-ray spectroscopy [32], surrounding the plasma trap, to tag the in-plasma nuclear β-decays via the γ-rays emitted from the excited states of the daughter nuclei.

In 2021 the activity of the collaboration was dedicated to the definition of the details of the overall project, reported in the specific Technical Design Report (TDR) [33], as well as to the start of the procurement phase of the main subsystems. As part of a Collaboration Agreement between the PANDORA and GAMMA collaborations, 16 HPGe detectors belonging to the GALILEO setup will be transferred from LNL to LNS in 2023. In the meantime, the phases of know-how transfer and specific skills on the operation, maintenance and management of germanium detectors have been started, including the development of a special laboratory at LNS, already in the design phase. Thanks to the CSN3 financial support, the procurement nowadays includes two RF power supplies (18GHz-Klystrons), a new X-ray-CCD camera, the first part of funding needed to start the so-called Competitive Dialogue (i.e., a negotiated procurement procedure) about the superconducting magnetic trap, that is the most expensive part of the project. Among the ongoing activities it is worth mentioning a preliminary numerical simulation study on the possibility of measuring the opacities of plasmas of astrophysical interest in PANDORA (kilonovae's ejecta), the study of expected abundances and constraints in AGB stars for some isotopes of interest for PANDORA; the experimental tests and benchmarks, using the normal conductive trap of ATOMKI-Debrecen, of magnetic confinement and turbulence in plasma; and the definition of the analysis algorithm for X imaging and space-resolved spectroscopy.

The first physics cases to investigate are $^{176}$Lu (potential cosmo-chronometer), $^{134}$Cs (to reproduce adequately the observed abundance ratio of the two s-only isotopes, $^{134}$Ba and $^{136}$Ba, see Sect. 5.3.1) and $^{94}$Nb (solving the puzzle about the exact contribution of s-processing to $^{94}$Mo).

* **BCT and I-LUCE**: the BCT facility (breast cancer therapy with radiosensitizers in proton therapy and conventional radiotherapy) has been recently funded by the Sicilian Region with the main aim to study and define new therapeutic approaches for radio-therapy, drugs development and new treatment modalities of breast carcinoma. The first phase will consist in the installation and commissioning of an ultrashort pulse power laser (50 TW, 25 fs) for the generation of laser-driven ion, proton (maximum energy of 5 MeV), electron (maximum energy of 200 MeV) and gamma beams mainly for radiobiological and preclinical irradiation studies. The second BCT phase will provide an increased laser power up to 250 TW, having a system designed to be upgradable up to 1 PW. From the nuclear physics point of view, the availability of this laser will allow one to carry out studies of reactions directly in plasmas, a topic of interest for nuclear astrophysics.

The I-LUCE (INFN—laser-induced particle acceleration) facility will make the new laser-driven beams available to the community for nuclear and multidisciplinary applications. The acceleration from laser-matter interaction is grafted, moreover, into the new radiotherapy method called “FLASH” in which radiation beams with very intense dose rates are used to irradiate tumors, allowing a huge saving of healthy tissues.

Ion acceleration driven by pulsed laser-plasma sources is an emerging field of research, resulting from recent high-power laser technology achievements in terms of ultrahigh intensities ($10^{21} \text{ W/cm}^2$) reached on target; as a reference, the first experiments done by LNS researchers in the second half of ‘90s used laser intensities $10^6$ times lower [34]. In addition, studies based on the interaction of high-density plasmas, generated in the interaction of the laser with matter, with the ion beams from the LNS accelerators are foreseen as a future and unique LNS capability, and this will open up a very wide range of perspectives, both in the field of nuclear physics and astrophysics.

* **In-air irradiation with ion beams**: LNS is equipped with a multidisciplinary beamline where several international groups perform innovative experiments for different kinds of application, from radiation damage study to irradiation of biological sample and of electronics devices. The new intensities, as well as the new radioactive beams, will open new perspectives for irradiation of samples under extreme conditions: high dose rate measurements and for mimicking of laser-driven accelerated beams or high-power pulsed beam from modern accelerators.

* **X-ray Tube**: an X-ray-based high-voltage (up to 320 kVp) facility, capable to deliver a homogeneous and shaped photon beam. It was designed to work with pulsed beams as well as in continuous mode, mainly to perform both 2D imaging and small animal/cells irradiations with doses that can be delivered up to several Gy. After the final commissioning, the X-ray tube will
* **PANDORA**: it will be a facility [27] conceived for multidisciplinary studies especially in the nuclear astrophysics framework. The main objective is to perform the first measurements of β-decays of astrophysical relevance in laboratory magnetized plasmas able to mimic some stellar-like conditions. The new experimental approach will allow to check the theoretical predictions about decay rates variation (expected to change dramatically as a function of the ionization state [28]). Only few experimental evidences were, in fact, collected up to now in storage rings (e.g., a lifetime reduction by 9 orders of magnitude was measured for $^{187}$Re [29]). Another relevant goal is to measure the opacities of plasmas of astrophysical interest (kilonovae's ejecta). PANDORA will mainly consist of three subsystems:

- an innovative superconducting magnetic plasma trap [30], capable to produce and confine plasmas with electron-ion densities up to $10^{13} \text{ cm}^{-3}$ and electron temperatures of $T_e \sim 0.1-30 \text{ keV}$;

- an advanced plasma multidiagnostic system [31], consisting of a set of noninvasive diagnostic tools capable of operating simultaneously for the non-intrusive monitoring of the thermodynamic plasma properties and the measurement of plasma parameters;

- an array of 14 HPGe (high-purity germanium) detectors for γ-ray spectroscopy [32], surrounding the plasma trap, to tag the in-plasma nuclear β-decays via the γ-rays emitted from the excited states of the daughter nuclei.

In 2021 the activity of the collaboration was dedicated to the definition of the details of the overall project, reported in the specific Technical Design Report (TDR) [33], as well as to the start of the procurement phase of the main subsystems. As part of a Collaboration Agreement between the PANDORA and GAMMA collaborations, 16 HPGe detectors belonging to the GALILEO setup will be transferred from LNL to LNS in 2023. In the meantime, the phases of know-how transfer and specific skills on the operation, maintenance and management of germanium detectors have been started, including the development of a special laboratory at LNS, already in the design phase. Thanks to the CSN3 financial support, the procurement nowadays includes two RF power supplies (18GHz-Klystrons), a new X-ray-CCD camera, the first part of funding needed to start the so-called Competitive Dialogue (i.e., a negotiated procurement procedure) about the superconducting magnetic trap, that is the most expensive part of the project. Among the ongoing activities it is worth mentioning a preliminary numerical simulation study on the possibility of measuring the opacities of plasmas of astrophysical interest in PANDORA (kilonovae's ejecta), the study of expected abundances and constraints in AGB stars for some isotopes of interest for PANDORA; the experimental tests and benchmarks, using the normal conductive trap of ATOMKI-Debrecen, of magnetic confinement and turbulence in plasma; and the definition of the analysis algorithm for X imaging and space-resolved spectroscopy.

The first physics cases to investigate are $^{176}$Lu (potential cosmo-chronometer), $^{134}$Cs (to reproduce adequately the observed abundance ratio of the two s-only isotopes, $^{134}$Ba and $^{136}$Ba, see Sect. 5.3.1) and $^{94}$Nb (solving the puzzle about the exact contribution of s-processing to $^{94}$Mo).

* **BCT and I-LUCE**: the BCT facility (breast cancer therapy with radiosensitizers in proton therapy and conventional radiotherapy) has been recently funded by the Sicilian Region with the main aim to study and define new therapeutic approaches for radio-therapy, drugs development and new treatment modalities of breast carcinoma. The first phase will consist in the installation and commissioning of an ultrashort pulse power laser (50 TW, 25 fs) for the generation of laser-driven ion, proton (maximum energy of 5 MeV), electron (maximum energy of 200 MeV) and gamma beams mainly for radiobiological and preclinical irradiation studies. The second BCT phase will provide an increased laser power up to 250 TW, having a system designed to be upgradable up to 1 PW. From the nuclear physics point of view, the availability of this laser will allow one to carry out studies of reactions directly in plasmas, a topic of interest for nuclear astrophysics.

The I-LUCE (INFN—laser-induced particle acceleration) facility will make the new laser-driven beams available to the community for nuclear and multidisciplinary applications. The acceleration from laser-matter interaction is grafted, moreover, into the new radiotherapy method called “FLASH” in which radiation beams with very intense dose rates are used to irradiate tumors, allowing a huge saving of healthy tissues.

Ion acceleration driven by pulsed laser-plasma sources is an emerging field of research, resulting from recent high-power laser technology achievements in terms of ultrahigh intensities ($10^{21} \text{ W/cm}^2$) reached on target; as a reference, the first experiments done by LNS researchers in the second half of ‘90s used laser intensities $10^6$ times lower [34]. In addition, studies based on the interaction of high-density plasmas, generated in the interaction of the laser with matter, with the ion beams from the LNS accelerators are foreseen as a future and unique LNS capability, and this will open up a very wide range of perspectives, both in the field of nuclear physics and astrophysics.

* **In-air irradiation with ion beams**: LNS is equipped with a multidisciplinary beamline where several international groups perform innovative experiments for different kinds of application, from radiation damage study to irradiation of biological sample and of electronics devices. The new intensities, as well as the new radioactive beams, will open new perspectives for irradiation of samples under extreme conditions: high dose rate measurements and for mimicking of laser-driven accelerated beams or high-power pulsed beam from modern accelerators.

* **X-ray Tube**: an X-ray-based high-voltage (up to 320 kVp) facility, capable to deliver a homogeneous and shaped photon beam. It was designed to work with pulsed beams as well as in continuous mode, mainly to perform both 2D imaging and small animal/cells irradiations with doses that can be delivered up to several Gy. After the final commissioning, the X-ray tube will
be fully available to nuclear physics users for various activities, such as X-ray beam calibration, radiation hardness studies, and detectors characterization.

## 3 Nuclear dynamics

Nuclear dynamics is a wide field of nuclear physics, involving a large number of phenomena and effects that allow to explore the relevant properties of the nuclear medium. Heavy-ion collisions (HIC) represent a powerful tool of investigation in this field, spanning a wide range of energies, producing different states of nuclear matter, and providing crucial information on various aspects, ranging from the nuclear equation of state (EOS) to the structure of nuclei and their decay modes, up to the dynamics of the nuclear reactions to produce nuclei in the region of “terra incognita”, far from the stability valley.

In the context of the Mid Term Plan of Nuclear Physics, we present the relevant, current, challenging and key physics cases in nuclear dynamics that we will be able to unravel at LNS thanks to the ongoing upgrade of the accelerator machines and of the available apparatuses, and to the installation of the fragment separator FraISe.

In the framework of nuclear dynamics, we have treated three principal items “Heavy-Ion Collision and Equation of State”, “Clustering” and “Fission Dynamics”.

Contributions and proposals discussed and emerged during the workshop are presented in detail in the devoted paragraphs.

The first item “Heavy-Ion Collision and Equation of State” (Sect. 3.1) explores some new ideas and devices that, by using stable and radioactive beams in the Fermi energy regime at the LNS, will improve our understanding of the symmetry energy constraints at densities below saturation. In this framework, the working group highlighted the $^{68}$Ni + $^{124}$Sn and $^{56}$Ni + $^{112}$Sn reactions using FraISe beams (tag LNS-ND-HIC-c0 reported in Table 4 and Sect. 3.1.3) and the $^{96}$Zr + $^{96}$Zr (N/Z = 1.4) and $^{96}$Ru + $^{96}$Ru (N/Z = 1.18) reactions using SC stable beams (tag LNS-ND-HIC-b0, reported in Table 4 and Sect. 3.1.3). The symmetry energy can be also investigated through the study of the dynamical dipole, an observable connected to the stiffness parameter, describing the potential term of the symmetry energy (see also Sect. 4.2.2). For these studies, it is proposed to use the new high-intensity SC stable beams of Ar and Ca isotopes on Ca or Ni targets (tag LNS-ND-HIC-b1 in Table 4 and Sect. 3.1.5).

Another interesting point is the study of the caloric curve of nuclear matter and its dependence on the neutron–proton asymmetry and on reaction dynamics. Different theoretical calculations are conflicting and few experimental data are existing. It is proposed to extend this study to the investigation of the reactions $^{34}$Ar + $^{58}$Ni and $^{46}$Ar + $^{64}$Ni at energies between 15 and 30 AMeV, taking advantage of the FraISe beams (2.2.2). For these reasons, the development of FraISe beams with A = 30–70 is strongly supported for their relevance in order to further progress in this area of research (tag LNS-ND-HIC-c1 in Table 4 and Sect. 3.1.4).

All the experiments described up to now can be implemented by using the 4π CHIMERA detector [23] and the FARCOS correlator [24].

Still in the domain of nuclear dynamics at Fermi energy and its links to the symmetry term in the EOS, some items are suggested mainly exploiting the enhanced isotopic identification capabilities of the FAZIA array. Among the most relevant beams, we mention neutron-poor Kr (including the stable $^{78}$Kr) or Ar beams (including the stable $^{36}$Ar) at 35 AMeV on $^{40}$Ca, $^{120}$Sn, $^{208}$Pb targets (tag LNS-ND-HIC-b2 in Table 4 and Sect. 3.1.7). Zero-degree configurations (i.e., modules with specific holding structures mounted at zero degree) can also be envisaged, to perform precise cross section measurements. Relevant reactions might be those induced by FraISe beams, $^{15}$C, $^{14}$Be and $^{16,20}$O, at 40 AMeV on $^{12}$C, $^{197}$Au targets (tag LNS-ND-HIC-c2 in Table 4 and Sect. 3.1.7).

The second item “Clustering” (Sect. 3.2) proposes some new ideas to carry out fine and very precise measurements of already known cluster states in a number of key nuclei, and to search for new cluster structures and their decays, in previously unstudied nuclei or even new mass regions. Investigations of cluster states other than providing results on clustering effects can also show the presence of neutron halos and skins, or alpha–condensate structures.

Among the highlights for this item, there is the study of the clustering structure of $^{10}$Be and $^{14}$C both produced in batch mode and accelerated by the TANDEM (tag LNS-ND-CLU-a0 in Table 4 and Sect. 3.2.1).

Besides, the availability of noble gas beams at the Tandem accelerator, for example, $^{4}$He, $^{3}$He or $^{20}$Ne, could lead to perform new interesting physics investigation on the structure of light-to-medium mass nuclei (tag LNS-ND-CLU-b0 in Table 4 and Sect. 3.2.3).

Others relevant experiments can be done by using exotic beams produced at FraISe, and benefiting from the high intensity of the beams delivered by the SC. For example, the study of the molecular states predicted for the $^{13}$B in breakup reactions (tag LNS-ND-CLU-a1 in Table 4 and Sect. 3.2.4).

An important subject concerning halo nuclei is how the halo can affect the reaction dynamics, and investigation in this field are proposed, by measuring elastic scattering and direct reaction angular distributions in collisions induced by different n-halo and p-halo beams, obtained by FraISe, on a $^{208}$Pb target at about 2–3 times the Coulomb barrier (tag LNS-ND-CLU-b1 in Table 4 and Sect. 3.2.4).

The third and last item is “Fission Dynamics” (Sect. 3.3) that presents three lines which can be experimentally addressed with the high-intensity facility under construction at the INFN-LNS: shell effects in fission and quasifission (Sect. 3.3.1), multinucleon transfer reactions to investigate “Terra Incognita” (Sect. 3.3.1), and a possible alternative pathway to produce superheavy elements (Sect. 3.3.5).
be fully available to nuclear physics users for various activities, such as X-ray beam calibration, radiation hardness studies, and detectors characterization.

## 3 Nuclear dynamics

Nuclear dynamics is a wide field of nuclear physics, involving a large number of phenomena and effects that allow to explore the relevant properties of the nuclear medium. Heavy-ion collisions (HIC) represent a powerful tool of investigation in this field, spanning a wide range of energies, producing different states of nuclear matter, and providing crucial information on various aspects, ranging from the nuclear equation of state (EOS) to the structure of nuclei and their decay modes, up to the dynamics of the nuclear reactions to produce nuclei in the region of “terra incognita”, far from the stability valley.

In the context of the Mid Term Plan of Nuclear Physics, we present the relevant, current, challenging and key physics cases in nuclear dynamics that we will be able to unravel at LNS thanks to the ongoing upgrade of the accelerator machines and of the available apparatuses, and to the installation of the fragment separator FraISe.

In the framework of nuclear dynamics, we have treated three principal items “Heavy-Ion Collision and Equation of State”, “Clustering” and “Fission Dynamics”.

Contributions and proposals discussed and emerged during the workshop are presented in detail in the devoted paragraphs.

The first item “Heavy-Ion Collision and Equation of State” (Sect. 3.1) explores some new ideas and devices that, by using stable and radioactive beams in the Fermi energy regime at the LNS, will improve our understanding of the symmetry energy constraints at densities below saturation. In this framework, the working group highlighted the $^{68}$Ni + $^{124}$Sn and $^{56}$Ni + $^{112}$Sn reactions using FraISe beams (tag LNS-ND-HIC-c0 reported in Table 4 and Sect. 3.1.3) and the $^{96}$Zr + $^{96}$Zr (N/Z = 1.4) and $^{96}$Ru + $^{96}$Ru (N/Z = 1.18) reactions using SC stable beams (tag LNS-ND-HIC-b0, reported in Table 4 and Sect. 3.1.3). The symmetry energy can be also investigated through the study of the dynamical dipole, an observable connected to the stiffness parameter, describing the potential term of the symmetry energy (see also Sect. 4.2.2). For these studies, it is proposed to use the new high-intensity SC stable beams of Ar and Ca isotopes on Ca or Ni targets (tag LNS-ND-HIC-b1 in Table 4 and Sect. 3.1.5).

Another interesting point is the study of the caloric curve of nuclear matter and its dependence on the neutron–proton asymmetry and on reaction dynamics. Different theoretical calculations are conflicting and few experimental data are existing. It is proposed to extend this study to the investigation of the reactions $^{34}$Ar + $^{58}$Ni and $^{46}$Ar + $^{64}$Ni at energies between 15 and 30 AMeV, taking advantage of the FraISe beams (2.2.2). For these reasons, the development of FraISe beams with A = 30–70 is strongly supported for their relevance in order to further progress in this area of research (tag LNS-ND-HIC-c1 in Table 4 and Sect. 3.1.4).

All the experiments described up to now can be implemented by using the 4π CHIMERA detector [23] and the FARCOS correlator [24].

Still in the domain of nuclear dynamics at Fermi energy and its links to the symmetry term in the EOS, some items are suggested mainly exploiting the enhanced isotopic identification capabilities of the FAZIA array. Among the most relevant beams, we mention neutron-poor Kr (including the stable $^{78}$Kr) or Ar beams (including the stable $^{36}$Ar) at 35 AMeV on $^{40}$Ca, $^{120}$Sn, $^{208}$Pb targets (tag LNS-ND-HIC-b2 in Table 4 and Sect. 3.1.7). Zero-degree configurations (i.e., modules with specific holding structures mounted at zero degree) can also be envisaged, to perform precise cross section measurements. Relevant reactions might be those induced by FraISe beams, $^{15}$C, $^{14}$Be and $^{16,20}$O, at 40 AMeV on $^{12}$C, $^{197}$Au targets (tag LNS-ND-HIC-c2 in Table 4 and Sect. 3.1.7).

The second item “Clustering” (Sect. 3.2) proposes some new ideas to carry out fine and very precise measurements of already known cluster states in a number of key nuclei, and to search for new cluster structures and their decays, in previously unstudied nuclei or even new mass regions. Investigations of cluster states other than providing results on clustering effects can also show the presence of neutron halos and skins, or alpha–condensate structures.

Among the highlights for this item, there is the study of the clustering structure of $^{10}$Be and $^{14}$C both produced in batch mode and accelerated by the TANDEM (tag LNS-ND-CLU-a0 in Table 4 and Sect. 3.2.1).

Besides, the availability of noble gas beams at the Tandem accelerator, for example, $^{4}$He, $^{3}$He or $^{20}$Ne, could lead to perform new interesting physics investigation on the structure of light-to-medium mass nuclei (tag LNS-ND-CLU-b0 in Table 4 and Sect. 3.2.3).

Others relevant experiments can be done by using exotic beams produced at FraISe, and benefiting from the high intensity of the beams delivered by the SC. For example, the study of the molecular states predicted for the $^{13}$B in breakup reactions (tag LNS-ND-CLU-a1 in Table 4 and Sect. 3.2.4).

An important subject concerning halo nuclei is how the halo can affect the reaction dynamics, and investigation in this field are proposed, by measuring elastic scattering and direct reaction angular distributions in collisions induced by different n-halo and p-halo beams, obtained by FraISe, on a $^{208}$Pb target at about 2–3 times the Coulomb barrier (tag LNS-ND-CLU-b1 in Table 4 and Sect. 3.2.4).

The third and last item is “Fission Dynamics” (Sect. 3.3) that presents three lines which can be experimentally addressed with the high-intensity facility under construction at the INFN-LNS: shell effects in fission and quasifission (Sect. 3.3.1), multinucleon transfer reactions to investigate “Terra Incognita” (Sect. 3.3.1), and a possible alternative pathway to produce superheavy elements (Sect. 3.3.5).
<table><caption>**Table 4** Tables with priorities and feasibility as addressed in the working group</caption><thead><tr><th>Tag</th><th>Description</th><th>Reaction</th><th>Phase</th></tr></thead><tbody><tr><td>LNS-ND-CLU-a0</td><td>Clustering structure of <sup>10</sup>Be, <sup>14</sup>C<br>Batch mode (<sup>10</sup>Be, <sup>14</sup>C)</td><td><sup>10</sup>Be → <sup>6</sup>He+<sup>4</sup>He<br><sup>10</sup>Be+<sup>4</sup>He → <sup>14</sup>C* → <sup>10</sup>Be+<sup>4</sup>He<br><sup>14</sup>C + α → <sup>18</sup>O <sup>14</sup>C + <sup>7</sup>Li → <sup>20</sup>O+p</td><td>A</td></tr><tr><td>LNS-ND-CLU-a1</td><td>Clustering structure of <sup>13</sup>B, <sup>18</sup>,<sup>20</sup>O<br>FraISe beam by SC</td><td><sup>13</sup>B → <sup>12</sup>Be+p, <sup>9</sup>Li+α, <sup>10</sup>Be+t, <sup>7</sup>Li+<sup>6</sup>He</td><td>A</td></tr><tr><td>LNS-ND-HIC-b0</td><td>E<sub>sym</sub> precision<br>Measurements ρ &lt; ρ<sub>0</sub><br>Stable beam by SC</td><td><sup>96</sup>Zr+<sup>96</sup>Zr <sup>96</sup>Ru+<sup>96</sup>Ru</td><td>B</td></tr><tr><td>LNS-ND-HIC-b1</td><td>E<sub>sym</sub> precision<br>Measurements ρ &lt; ρ<sub>0</sub><br>Stable beam by SC</td><td><sup>x</sup>Ar, <sup>x</sup>Ca+<sup>x</sup>Ca, <sup>x</sup>Ni</td><td>B</td></tr><tr><td>LNS-ND-HIC-b2</td><td>E<sub>sym</sub> precision<br>Measurements ρ &lt; ρ<sub>0</sub><br>Stable beam by SC</td><td><sup>56</sup>Fe, <sup>78</sup>Kr+<sup>40</sup>Ca, <sup>120</sup>Sn, <sup>208</sup>Pb</td><td>B</td></tr><tr><td>LNS-ND-CLU-b0</td><td>Cluster in <sup>13</sup>C<br>Cluster in p-rich environment<br>Noble gas by Tandem</td><td><sup>4</sup>He+<sup>9</sup>Be, <sup>10</sup>,<sup>11</sup>B, <sup>13</sup>C → <sup>13</sup>C*, <sup>14</sup>, <sup>15</sup>N*, <sup>17</sup>O*</td><td>B</td></tr><tr><td>LNS-ND-CLU-b1</td><td>Halo effect on dynamics<br>FraISe beam by SC</td><td><sup>3</sup>He+<sup>6</sup>Li, <sup>10</sup>B, <sup>12</sup>C, <sup>14</sup>N, <sup>16</sup>O</td><td>B</td></tr><tr><td>LNS-ND-FIS-b0</td><td>Exploring Magic Numbers<br>Stable beam by SC</td><td><sup>14</sup>B, <sup>15</sup>C, <sup>17</sup>Ne+ <sup>208</sup>Pb</td><td>B</td></tr><tr><td>LNS-ND-FIS-b1</td><td>SHE Production<br>Multinucleon transfer reactions<br>Stable beam by SC</td><td><sup>48</sup>Ca + <sup>208</sup>Pb, <sup>232</sup>Th, <sup>238</sup>Th → <sup>256</sup>No, <sup>280</sup>Os, <sup>286</sup>Cn<br><sup>22</sup>Ne + <sup>238</sup>U, <sup>232</sup>Th → <sup>260</sup>No, <sup>254</sup>Fm<br><sup>122</sup>Sn + <sup>208</sup>Pb <sup>136</sup>Xe + <sup>202</sup>Os<br><sup>70</sup>Zn + <sup>232</sup>Th <sup>70</sup>Zn + <sup>238</sup>U</td><td>B</td></tr><tr><td>LNS-ND-FIS-b2</td><td>SHE Production<br>2 body reactions<br>Stable beam by SC</td><td><sup>48</sup>Ca + <sup>238</sup>Th<br><sup>32</sup>S + <sup>238</sup>U → <sup>4</sup>He + <sup>266</sup>Sg<br><sup>66</sup>Zn + <sup>232</sup>Th → <sup>4</sup>He + <sup>294</sup>Og<br><sup>18</sup>O + <sup>120</sup>Sn → <sup>4</sup>He + <sup>134</sup>Ba</td><td>B</td></tr><tr><td>LNS-ND-HIC-c0</td><td>E<sub>sym</sub> precision<br>Measurements ρ &lt; ρ<sub>0</sub><br>FraISe beam by SC</td><td><sup>68</sup>Ni+<sup>124</sup>Sn <sup>56</sup>Ni+<sup>112</sup>Sn</td><td>C</td></tr><tr><td>LNS-ND-HIC-c1</td><td>Isospin dependence of<br>Nuclear caloric curve<br>FraISe beam by SC</td><td><sup>34</sup>Ar+<sup>58</sup>Ni <sup>46</sup>Ar+<sup>64</sup>Ni</td><td>C</td></tr><tr><td>LNS-ND-HIC-c2</td><td>Fragmentation cross section<br>Precision measurement<br>FraISe beam by SC</td><td><sup>15</sup>C, <sup>14</sup>Be, <sup>16</sup>,<sup>20</sup>O + <sup>12</sup>C, <sup>197</sup>Au</td><td>C</td></tr></tbody></table>

Planning experiments to investigate shell effect in supersymmetric fission and quasifission need, other than high beam intensity, the capability of measuring the charge and the mass of fragments in the region of mass about 70–80 a.m.u. This can be achieved with the MAGNEX spectrometer, adding a time-of-flight arm, on the opposite side, to select the reaction mechanism. Main reactions for the supersymmetric channel and for which high-intensity beams will be available are <sup>22</sup>Ne + <sup>238</sup>U → <sup>260</sup>No and <sup>22</sup>Ne + <sup>232</sup>Th → <sup>254</sup>Fm. Reactions that might be a possible channel for <sup>78</sup>Ni production are <sup>48</sup>Ca induced on <sup>208</sup>Pb, <sup>232</sup>Th and <sup>238</sup>U (tag LNS-ND-FIS-b0 in Table 4 and Sect. 3.3.3).

In this framework, multinucleon transfer (Sect. 3.3.4) is the best mechanism to produce neutron-rich isotopes of the Terra Incognita below <sup>208</sup>Pb, with production cross sections ranging from a few mb to a few pb. Interesting case is, for example, the reaction <sup>122</sup>Sn + <sup>208</sup>Pb (tag LNS-ND-FIS-b1 in Table 4 and Sect. 3.3.4).
<table><caption>**Table 4** Tables with priorities and feasibility as addressed in the working group</caption><thead><tr><th>Tag</th><th>Description</th><th>Reaction</th><th>Phase</th></tr></thead><tbody><tr><td>LNS-ND-CLU-a0</td><td>Clustering structure of <sup>10</sup>Be, <sup>14</sup>C<br>Batch mode (<sup>10</sup>Be, <sup>14</sup>C)</td><td><sup>10</sup>Be → <sup>6</sup>He+<sup>4</sup>He<br><sup>10</sup>Be+<sup>4</sup>He → <sup>14</sup>C* → <sup>10</sup>Be+<sup>4</sup>He<br><sup>14</sup>C + α → <sup>18</sup>O <sup>14</sup>C + <sup>7</sup>Li → <sup>20</sup>O+p</td><td>A</td></tr><tr><td>LNS-ND-CLU-a1</td><td>Clustering structure of <sup>13</sup>B, <sup>18</sup>,<sup>20</sup>O<br>FraISe beam by SC</td><td><sup>13</sup>B → <sup>12</sup>Be+p, <sup>9</sup>Li+α, <sup>10</sup>Be+t, <sup>7</sup>Li+<sup>6</sup>He</td><td>A</td></tr><tr><td>LNS-ND-HIC-b0</td><td>E<sub>sym</sub> precision<br>Measurements ρ &lt; ρ<sub>0</sub><br>Stable beam by SC</td><td><sup>96</sup>Zr+<sup>96</sup>Zr <sup>96</sup>Ru+<sup>96</sup>Ru</td><td>B</td></tr><tr><td>LNS-ND-HIC-b1</td><td>E<sub>sym</sub> precision<br>Measurements ρ &lt; ρ<sub>0</sub><br>Stable beam by SC</td><td><sup>x</sup>Ar, <sup>x</sup>Ca+<sup>x</sup>Ca, <sup>x</sup>Ni</td><td>B</td></tr><tr><td>LNS-ND-HIC-b2</td><td>E<sub>sym</sub> precision<br>Measurements ρ &lt; ρ<sub>0</sub><br>Stable beam by SC</td><td><sup>56</sup>Fe, <sup>78</sup>Kr+<sup>40</sup>Ca, <sup>120</sup>Sn, <sup>208</sup>Pb</td><td>B</td></tr><tr><td>LNS-ND-CLU-b0</td><td>Cluster in <sup>13</sup>C<br>Cluster in p-rich environment<br>Noble gas by Tandem</td><td><sup>4</sup>He+<sup>9</sup>Be, <sup>10,11</sup>B, <sup>13</sup>C → <sup>13</sup>C*, <sup>14,15</sup>N*, <sup>17</sup>O*</td><td>B</td></tr><tr><td>LNS-ND-CLU-b1</td><td>Halo effect on dynamics<br>FraISe beam by SC</td><td><sup>3</sup>He+<sup>6</sup>Li, <sup>10</sup>B, <sup>12</sup>C, <sup>14</sup>N, <sup>16</sup>O</td><td>B</td></tr><tr><td>LNS-ND-FIS-b0</td><td>Exploring Magic Numbers<br>Stable beam by SC</td><td><sup>14</sup>B, <sup>15</sup>C, <sup>17</sup>Ne+ <sup>208</sup>Pb</td><td>B</td></tr><tr><td>LNS-ND-FIS-b1</td><td>SHE Production<br>Multinucleon transfer reactions<br>Stable beam by SC</td><td><sup>48</sup>Ca + <sup>208</sup>Pb, <sup>232</sup>Th, <sup>238</sup>Th → <sup>256</sup>No, <sup>280</sup>Os, <sup>286</sup>Cn<br><sup>22</sup>Ne + <sup>238</sup>U, <sup>232</sup>Th → <sup>260</sup>No, <sup>254</sup>Fm<br><sup>122</sup>Sn + <sup>208</sup>Pb <sup>136</sup>Xe + <sup>202</sup>Os<br><sup>70</sup>Zn + <sup>232</sup>Th <sup>70</sup>Zn + <sup>238</sup>U</td><td>B</td></tr><tr><td>LNS-ND-FIS-b2</td><td>SHE Production<br>2 body reactions<br>Stable beam by SC</td><td><sup>48</sup>Ca + <sup>238</sup>Th<br><sup>32</sup>S + <sup>238</sup>U → <sup>4</sup>He + <sup>266</sup>Sg<br><sup>66</sup>Zn + <sup>232</sup>Th → <sup>4</sup>He + <sup>294</sup>Og<br><sup>18</sup>O + <sup>120</sup>Sn → <sup>4</sup>He + <sup>134</sup>Ba</td><td>B</td></tr><tr><td>LNS-ND-HIC-c0</td><td>E<sub>sym</sub> precision<br>Measurements ρ &lt; ρ<sub>0</sub><br>FraISe beam by SC</td><td><sup>68</sup>Ni+<sup>124</sup>Sn <sup>56</sup>Ni+<sup>112</sup>Sn</td><td>C</td></tr><tr><td>LNS-ND-HIC-c1</td><td>Isospin dependence of<br>Nuclear caloric curve<br>FraISe beam by SC</td><td><sup>34</sup>Ar+<sup>58</sup>Ni <sup>46</sup>Ar+<sup>64</sup>Ni</td><td>C</td></tr><tr><td>LNS-ND-HIC-c2</td><td>Fragmentation cross section<br>Precision measurement<br>FraISe beam by SC</td><td><sup>15</sup>C, <sup>14</sup>Be, <sup>16,20</sup>O + <sup>12</sup>C, <sup>197</sup>Au</td><td>C</td></tr></tbody></table>

Planning experiments to investigate shell effect in supersymmetric fission and quasifission need, other than high beam intensity, the capability of measuring the charge and the mass of fragments in the region of mass about 70–80 a.m.u. This can be achieved with the MAGNEX spectrometer, adding a time-of-flight arm, on the opposite side, to select the reaction mechanism. Main reactions for the supersymmetric channel and for which high-intensity beams will be available are <sup>22</sup>Ne + <sup>238</sup>U → <sup>260</sup>No and <sup>22</sup>Ne + <sup>232</sup>Th → <sup>254</sup>Fm. Reactions that might be a possible channel for <sup>78</sup>Ni production are <sup>48</sup>Ca induced on <sup>208</sup>Pb, <sup>232</sup>Th and <sup>238</sup>U (tag LNS-ND-FIS-b0 in Table 4 and Sect. 3.3.3).

In this framework, multinucleon transfer (Sect. 3.3.4) is the best mechanism to produce neutron-rich isotopes of the Terra Incognita below <sup>208</sup>Pb, with production cross sections ranging from a few mb to a few pb. Interesting case is, for example, the reaction <sup>122</sup>Sn + <sup>208</sup>Pb (tag LNS-ND-FIS-b1 in Table 4 and Sect. 3.3.4).
<figure><img src="image_16.png" /><figcaption>Fig. 16 Highlight for nuclear dynamics for the three items and temporal phases A, B, C</figcaption></figure>

Finally, a possible pathway to produce superheavy elements by two-body reactions is suggested (Sect. 3.3.6). A typical reaction could be $^{32}$S(193 MeV) + $^{238}$U→ α + $^{266}$Sg or $^{66}$Zn (363 MeV) + $^{232}$Th → α + $^{294}$Og (tag LNS-ND-FIS-b2 in Table 4 and Sect. 3.3.6).

Figure 16 summarizes the highlights for each item, inserted in a timeline of the upgrades at LNS, called Phase A, B, C.

At the end of this section, we show a table with the list of the selected nuclear reactions proposed for the realization of the highlighted goal and addressing to the experiments described in the text.

## 3.1 Heavy-ion collisions: EOS

### 3.1.1 Introduction

A unique aspect in the study of HIC is the production of nuclear matter in different conditions of excitation energy, temperature and density. In this way, it is possible to form, in a short interaction time, large density variations and transient states of nuclear matter: this is the optimal condition to study the nuclear EOS under laboratory controlled conditions as a function of the isospin asymmetry $δ = (ρ_n - ρ_p)/ρ$ and barionic densities, where n and p refer to neutron and proton numbers, respectively. In asymmetric nuclear matter, the EOS can be written as a sum of the energy per nucleon for the symmetric nuclear matter $E(ρ, δ = 0)$ and the symmetry energy term $E_{sym}(ρ)$, quadratic with respect to $δ$ [35, 36]: $E(ρ, δ) = E(ρ, δ = 0) + E_{sym}(ρ)δ^2$.

The symmetry energy term can be expanded around its value at nuclear saturation density ($ρ_0 = 0.16 fm^{-3}$):

$$E_{sym}(\rho) = E_{sym,0} + \frac{L}{3} \left( \frac{\rho - \rho_o}{\rho_o} \right) + \frac{K_{sym}}{18} \left( \frac{\rho - \rho_o}{\rho_o} \right)^2 + \dots \quad (1)$$

where $E_{sym,0} = S_0$, $L = 3 \left( \frac{\partial E_{sym}}{\partial \rho} \right) \bigg|_{\rho_0}$ and $K_{sym}$ are, respectively, the value of symmetry energy, the slope (related to the neutron pressure in asymmetric nuclear matter) and the curvature at $ρ_0$. These parameters, and particularly L, have been correlated to several observables in nuclear structure, nuclear dynamics and astrophysics [37, 38]. For example, simulations of neutron-star properties require as main input a model for the EOS as a function of a wide range of densities and isospin asymmetries, from low-density asymmetric matter (neutron-star crust) toward very high densities (outer core). On the other hand, the neutron-skin thickness of neutron-rich nuclei [39, 40] or their electric dipole polarizability, related to the giant dipole resonance (GDR) [41], also depends upon the symmetry energy parametrization. This means that the symmetry term of EOS in asymmetric nuclear matter affects the radius of a given mass neutron star, the neutron skin of a neutron-rich nucleus like $^{208}$Pb or $^{48}$Ca [42] as well as the dynamic evolution of HICs, because it is related to the fundamental properties of nuclear effective interaction [43]. Moreover, the recent detection of gravitation waves (GW) [44] from the merger of a binary neutron-star system has shown relevant correlations with the EOS and symmetry energy predicting the radius R of a neutron star (the so-called *tidal polarizability* $\Lambda$ observable in a GW event is in fact roughly proportional to $R^5$) opening the so-called multimessenger astronomy [45, 46] filed. These astrophysical studies can be now compared with those coming from terrestrial experiments, mainly by using HICs.
<figure><img src="image_16.png" /><figcaption>Fig. 16 Highlight for nuclear dynamics for the three items and temporal phases A, B, C</figcaption></figure>

Finally, a possible pathway to produce superheavy elements by two-body reactions is suggested (Sect. 3.3.6). A typical reaction could be ³²S(193 MeV) + ²³⁸U → α + ²⁶⁶Sg or ⁶⁶Zn (363 MeV) + ²³²Th → α + ²⁹⁴Og (tag LNS-ND-FIS-b2 in Table 4 and Sect. 3.3.6).

Figure 16 summarizes the highlights for each item, inserted in a timeline of the upgrades at LNS, called Phase A, B, C.

At the end of this section, we show a table with the list of the selected nuclear reactions proposed for the realization of the highlighted goal and addressing to the experiments described in the text.

## 3.1 Heavy-ion collisions: EOS

### 3.1.1 Introduction

A unique aspect in the study of HIC is the production of nuclear matter in different conditions of excitation energy, temperature and density. In this way, it is possible to form, in a short interaction time, large density variations and transient states of nuclear matter: this is the optimal condition to study the nuclear EOS under laboratory controlled conditions as a function of the isospin asymmetry $\delta = (\rho_n - \rho_p)/\rho$ and barionic densities, where n and p refer to neutron and proton numbers, respectively. In asymmetric nuclear matter, the EOS can be written as a sum of the energy per nucleon for the symmetric nuclear matter $E(\rho, \delta = 0)$ and the symmetry energy term $E_{sym}(\rho)$, quadratic with respect to $\delta$ [35, 36]: $E(\rho, \delta) = E(\rho, \delta = 0) + E_{sym}(\rho)\delta^2$.

The symmetry energy term can be expanded around its value at nuclear saturation density ($\rho_0 = 0.16 \text{ fm}^{-3}$):

$$E_{sym}(\rho) = E_{sym,0} + \frac{L}{3} \left( \frac{\rho - \rho_0}{\rho_0} \right) + \frac{K_{sym}}{18} \left( \frac{\rho - \rho_0}{\rho_0} \right)^2 + \dots \quad (1)$$

where $E_{sym,0} = S_0$, $L = 3 \left( \frac{\partial E_{sym}}{\partial \rho} \right)_{\rho_0}$ and $K_{sym}$ are, respectively, the value of symmetry energy, the slope (related to the neutron pressure in asymmetric nuclear matter) and the curvature at $\rho_0$. These parameters, and particularly L, have been correlated to several observables in nuclear structure, nuclear dynamics and astrophysics [37, 38]. For example, simulations of neutron-star properties require as main input a model for the EOS as a function of a wide range of densities and isospin asymmetries, from low-density asymmetric matter (neutron-star crust) toward very high densities (outer core). On the other hand, the neutron-skin thickness of neutron-rich nuclei [39, 40] or their electric dipole polarizability, related to the giant dipole resonance (GDR) [41], also depends upon the symmetry energy parametrization. This means that the symmetry term of EOS in asymmetric nuclear matter affects the radius of a given mass neutron star, the neutron skin of a neutron-rich nucleus like ²⁰⁸Pb or ⁴⁸Ca [42] as well as the dynamic evolution of HICs, because it is related to the fundamental properties of nuclear effective interaction [43]. Moreover, the recent detection of gravitation waves (GW) [44] from the merger of a binary neutron-star system has shown relevant correlations with the EOS and symmetry energy predicting the radius R of a neutron star (the so-called *tidal polarizability* $\Lambda$ observable in a GW event is in fact roughly proportional to $R^5$) opening the so-called multimessenger astronomy [45, 46] filed. These astrophysical studies can be now compared with those coming from terrestrial experiments, mainly by using HICs.
**Fig. 17** Adapted and modified from Burgio et al. [47]: correlation between the symmetry energy at saturation $S_0$ and the slope of the symmetry energy around saturation density. The shaded area corresponds to experimental data. In particular the cyan area (HIC) corresponds to isospin diffusion data on Sn+Sn collisions [48]. Black symbols correspond to results of theoretical microscopic approaches to EOS or (other colors) phenomenological approaches (see text and Ref. [47] for details). Gray area corresponds to AsyEos, Au+Au data from Ref. [49]. The impact of the PREX-II data analysis results [50] is also shown on the right

<figure><img src="image_17.png" /></figure>

Figure 17 shows a recent compilation of the constraints in the symmetry energy $S_0$ versus the slope $L$ obtained from different sources; in particular the shaded bands show experimental data from studies on HICs at the Fermi energies and isospin diffusion [48], neutron-skin thicknesses in Sn [51], electric dipole polarizability in GDR [52], isobaric-analog-state (IAS) analysis and neutron-skin data [53], and from calculations on mass and radius measurements for neutron stars [54] (see ref. [47] for a detailed description). Investigations on the symmetry energy have been also conducted exploiting other collective motions in neutron-rich nuclei such as the pygmy dipole resonances [55] or the giant monopole resonances [56] (see Sect. 4.2.3).

A compilation of 53 experimental results [57] gives the values of $31.7 \pm 3.20$ MeV and $58.7 \pm 28.1$ MeV for $S_0$ and $L$, respectively. It is interesting to note in Fig. 17 that the neutron-skin thickness for $^{208}$Pb, on PREX-II data, based on measurement of the parity-violating asymmetry in the elastic scattering of longitudinally polarized electrons off $^{208}$Pb [50, 58], brings to an average slope parameter $L = 106 \pm 37$ MeV, larger than previous values obtained from microscopic theoretical approaches and experimental data. A missing aspect in the plot of Fig. 17 is that it does not show the barionic density domain that is really explored in the experimental data while this information is indeed a fundamental ingredient [59]. Also microscopic “ab-initio” calculations are generally done around the saturation density and the results are extrapolated toward higher densities [60, 61]. In Fig. 17 we have drawn results of the ASYEOS experiment on Au+Au at 400 AMeV at GSI [49] as gray band. This experiment explores the supra-saturation density region in the range $1.5-2 \rho_0$ where few experimental data exist [62–64], by measuring the elliptic flows of neutrons and light charged particles [49, 65]. Results have shown a noticeable coherence with data coming from astrophysical observations [66, 67].

The consistency of the measurements conducted below and above saturation density is an important challenge also in the context of the “multimessenger” physics and in order to further constrain the coherence of different transport models. In the following, exploring some new ideas or devices, we show how the use of new stable and radioactive beams at LNS could contribute to improve the precision and reliability of symmetry energy constraints at densities below the saturation one.

### 3.1.2 Plans for midterm advances at LNS with SC beams

In the Fermi energy regime, various reaction mechanisms have been used to probe the symmetry energy at low density from $\rho_0$ down to $0.1 \rho_0$ where clusterization occurs [68–70]. From central collisions (multifragmentation and the experimental isoscaling phenomena [71], studies of emitted neutron-proton ratios [72]) to semi-peripheral reactions (isospin diffusion [48, 73, 74] and migration through the “neck” [75–77]) many experimental and theoretical contributions have been given to this research line (see the Refs. [78, 79] for some reviews). One of the basic ideas in constraining the symmetry energy at low densities is to look at N/Z of particles and intermediate mass fragments (IMF) emitted from semi-central to semi-peripheral reactions by using projectiles and targets with large isospin asymmetries with stable neutron-rich, neutron-poor or radioactive beams. Isospin transport effects appear as being caused by processes like the isospin diffusion and equilibration or the IMF emission from a transient “neck” region. All these phenomena are related to experimental observables that, in comparison with transport model calculations, can provide information on the density dependence of the symmetry energy. For example, in the neck fragmentation mechanism it is supposed that light
**Fig. 17** Adapted and modified from Burgio et al. [47]: correlation between the symmetry energy at saturation $S_0$ and the slope of the symmetry energy around saturation density. The shaded area corresponds to experimental data. In particular the cyan area (HIC) corresponds to isospin diffusion data on Sn+Sn collisions [48]. Black symbols correspond to results of theoretical microscopic approaches to EOS or (other colors) phenomenological approaches (see text and Ref. [47] for details). Gray area corresponds to AsyEos, Au+Au data from Ref. [49]. The impact of the PREX-II data analysis results [50] is also shown on the right

<figure><img src="image_17.png" /></figure>

Figure 17 shows a recent compilation of the constraints in the symmetry energy $S_0$ versus the slope $L$ obtained from different sources; in particular the shaded bands show experimental data from studies on HICs at the Fermi energies and isospin diffusion [48], neutron-skin thicknesses in Sn [51], electric dipole polarizability in GDR [52], isobaric-analog-state (IAS) analysis and neutron-skin data [53], and from calculations on mass and radius measurements for neutron stars [54] (see ref. [47] for a detailed description). Investigations on the symmetry energy have been also conducted exploiting other collective motions in neutron-rich nuclei such as the pygmy dipole resonances [55] or the giant monopole resonances [56] (see Sect. 4.2.3).

A compilation of 53 experimental results [57] gives the values of $31.7 \pm 3.20$ MeV and $58.7 \pm 28.1$ MeV for $S_0$ and $L$, respectively. It is interesting to note in Fig. 17 that the neutron-skin thickness for $^{208}$Pb, on PREX-II data, based on measurement of the parity-violating asymmetry in the elastic scattering of longitudinally polarized electrons off $^{208}$Pb [50, 58], brings to an average slope parameter $L = 106 \pm 37$ MeV, larger than previous values obtained from microscopic theoretical approaches and experimental data. A missing aspect in the plot of Fig. 17 is that it does not show the barionic density domain that is really explored in the experimental data while this information is indeed a fundamental ingredient [59]. Also microscopic “ab-initio” calculations are generally done around the saturation density and the results are extrapolated toward higher densities [60, 61]. In Fig. 17 we have drawn results of the ASYEOS experiment on Au+Au at 400 AMeV at GSI [49] as gray band. This experiment explores the supra-saturation density region in the range $1.5-2 \rho_0$ where few experimental data exist [62–64], by measuring the elliptic flows of neutrons and light charged particles [49, 65]. Results have shown a noticeable coherence with data coming from astrophysical observations [66, 67].

The consistency of the measurements conducted below and above saturation density is an important challenge also in the context of the “multimessenger” physics and in order to further constrain the coherence of different transport models. In the following, exploring some new ideas or devices, we show how the use of new stable and radioactive beams at LNS could contribute to improve the precision and reliability of symmetry energy constraints at densities below the saturation one.

### 3.1.2 Plans for midterm advances at LNS with SC beams

In the Fermi energy regime, various reaction mechanisms have been used to probe the symmetry energy at low density from $\rho_0$ down to $0.1 \rho_0$ where clusterization occurs [68–70]. From central collisions (multifragmentation and the experimental isoscaling phenomena [71], studies of emitted neutron-proton ratios [72]) to semi-peripheral reactions (isospin diffusion [48, 73, 74] and migration through the “neck” [75–77]) many experimental and theoretical contributions have been given to this research line (see the Refs. [78, 79] for some reviews). One of the basic ideas in constraining the symmetry energy at low densities is to look at N/Z of particles and intermediate mass fragments (IMF) emitted from semi-central to semi-peripheral reactions by using projectiles and targets with large isospin asymmetries with stable neutron-rich, neutron-poor or radioactive beams. Isospin transport effects appear as being caused by processes like the isospin diffusion and equilibration or the IMF emission from a transient “neck” region. All these phenomena are related to experimental observables that, in comparison with transport model calculations, can provide information on the density dependence of the symmetry energy. For example, in the neck fragmentation mechanism it is supposed that light
**Fig. 18** Adapted from Ref. [86]: ratio of the dynamical component to the total (dynamical+statistical) value in the breakup of the quasi-projectile plotted as a function of the IMF atomic number Z, for the three isobaric systems $^{124}$Xe+$^{64}$Zn (empty circles), $^{124}$Xe + $^{64}$Ni (full triangles) $^{124}$Sn + $^{64}$Ni (full circles) and for the $^{112}$Sn + $^{58}$Ni (empty triangles)

<figure><img src="image_18.png" /></figure>

IMFs are formed in a dilute n-rich matter in contact with the regions of projectile-like (PLF) and target-like (TLF) fragments at normal densities due to transport of neutrons toward the low-density region [80]. The interplay between experiments and transport model calculations is essential. In the last years, a big effort has been done (and it is in progress) in order to test the robustness of transport model predictions in reaching consistent conclusions with experimental data [81].

Many aspect of this physics case have been independently studied at INFN-LNS by the CHIMERA and INDRA-FAZIA collaborations and by other groups worldwide. All these subjects are related with the density dependence of the isovector part of the nuclear effective interaction and with the in-medium correlation effects; in particular, the latter focus on the microscopic mechanism to form clusters or fragments during the short interaction time when the transient systems explore “exotic” regions of EOS.

New exciting opportunities will be opened by the high-intensity heavy-ion beams and the radioactive beams at Fermi energies delivered by the SC after the upgrade. In fact, a higher sensitivity to the symmetry energy is expected both in experimental observables and theoretical models if we increase the strength of the N/Z dependent observable (by using, for example, more neutron-rich or neutron-poor beams) and at the same time if we improve the experimental device capabilities: (i) better isotopic resolution of fragments, (ii) capability to detect neutrons and charged particles simultaneously, and (iii) high granularity, as it will be presented in the sections below.

### 3.1.3 Plans with CHIMERA and FARCOS devices in semi-peripheral reactions

The CHIMERA $4\pi$ detector [23] has been used both in studies of nuclear EOS in asymmetric nuclear matter at LNS in the Fermi energy regime [82], and in the relativistic energy domain at GSI [49]. The new FARCOS array correlator [24] in its final configuration of 20 telescopes has been recently added. Many experiments have been performed with the CHIMERA detector in the last two decades and more recently by using a portion of the FARCOS array in different configurations [83]. Isospin properties of IMFs were used to constrain the density dependence of the symmetry energy at sub-saturation densities by using observables based on the transport of isospin like the isospin diffusion and N/Z equilibration [73, 84], and the isospin migration of neutrons and protons in the “neck” region [75, 85] causing the neutron enrichment of the light IMFs emitted at mid-rapidity. Values of parameters constraining the symmetry energy at sub-saturation densities were found comparing the experimental data with different transport models.

Unlike the light IMFs, the dynamical emission of heavier IMFs takes place over longer timescales, mainly due to a non-equilibrated breakup of the PLF (“dynamical fission”) [87, 88] in competition with the statistical emission. A recent study at 35 AMeV of the isobaric systems $^{124}$Xe, $^{124}$Sn + $^{64}$Zn, $^{64}$Ni and $^{112}$Sn + $^{58}$Ni has shown, as highlighted in Fig. 18 from Ref. [86], that the strength of dynamical effects increases with the isospin content of projectile and target, giving evidence of an important dependence of the reaction mechanism evolution on the initial neutron richness of both projectile and target colliding nuclei. This suggests the role of the symmetry energy in the dynamical process.

On the basis of these results, it is suggested to use the capabilities of the new FraISe fragment separator to produce $^{68}$Ni and $^{56}$Ni beams using primary ones of $^{70}$Zn and $^{58}$Ni, respectively, at an incident energy of about 25 AMeV. This will increase the N/Z of the initial systems, for example, to study $^{68}$Ni+$^{124}$Sn (neutron-rich, N/Z = 1.46) and $^{56}$Ni+$^{112}$Sn (neutron-poor, N/Z = 1.15) (tag LNS-ND-HIC-c0 in Table 4). These asymmetries, wider than those used in the past, enhance the sensitivity to the symmetry energy
**Fig. 18** Adapted from Ref. [86]: ratio of the dynamical component to the total (dynamical+statistical) value in the breakup of the quasi-projectile plotted as a function of the IMF atomic number Z, for the three isobaric systems $^{124}$Xe+$^{64}$Zn (empty circles), $^{124}$Xe + $^{64}$Ni (full triangles) $^{124}$Sn + $^{64}$Ni (full circles) and for the $^{112}$Sn + $^{58}$Ni (empty triangles)

<figure><img src="image_18.png" /></figure>

IMFs are formed in a dilute n-rich matter in contact with the regions of projectile-like (PLF) and target-like (TLF) fragments at normal densities due to transport of neutrons toward the low-density region [80]. The interplay between experiments and transport model calculations is essential. In the last years, a big effort has been done (and it is in progress) in order to test the robustness of transport model predictions in reaching consistent conclusions with experimental data [81].

Many aspect of this physics case have been independently studied at INFN-LNS by the CHIMERA and INDRA-FAZIA collaborations and by other groups worldwide. All these subjects are related with the density dependence of the isovector part of the nuclear effective interaction and with the in-medium correlation effects; in particular, the latter focus on the microscopic mechanism to form clusters or fragments during the short interaction time when the transient systems explore “exotic” regions of EOS.

New exciting opportunities will be opened by the high-intensity heavy-ion beams and the radioactive beams at Fermi energies delivered by the SC after the upgrade. In fact, a higher sensitivity to the symmetry energy is expected both in experimental observables and theoretical models if we increase the strength of the N/Z dependent observable (by using, for example, more neutron-rich or neutron-poor beams) and at the same time if we improve the experimental device capabilities: (i) better isotopic resolution of fragments, (ii) capability to detect neutrons and charged particles simultaneously, and (iii) high granularity, as it will be presented in the sections below.

### 3.1.3 Plans with CHIMERA and FARCOS devices in semi-peripheral reactions

The CHIMERA 4π detector [23] has been used both in studies of nuclear EOS in asymmetric nuclear matter at LNS in the Fermi energy regime [82], and in the relativistic energy domain at GSI [49]. The new FARCOS array correlator [24] in its final configuration of 20 telescopes has been recently added. Many experiments have been performed with the CHIMERA detector in the last two decades and more recently by using a portion of the FARCOS array in different configurations [83]. Isospin properties of IMFs were used to constrain the density dependence of the symmetry energy at sub-saturation densities by using observables based on the transport of isospin like the isospin diffusion and N/Z equilibration [73, 84], and the isospin migration of neutrons and protons in the “neck” region [75, 85] causing the neutron enrichment of the light IMFs emitted at mid-rapidity. Values of parameters constraining the symmetry energy at sub-saturation densities were found comparing the experimental data with different transport models.

Unlike the light IMFs, the dynamical emission of heavier IMFs takes place over longer timescales, mainly due to a non-equilibrated breakup of the PLF (“dynamical fission”) [87, 88] in competition with the statistical emission. A recent study at 35 AMeV of the isobaric systems $^{124}$Xe, $^{124}$Sn + $^{64}$Zn, $^{64}$Ni and $^{112}$Sn + $^{58}$Ni has shown, as highlighted in Fig. 18 from Ref. [86], that the strength of dynamical effects increases with the isospin content of projectile and target, giving evidence of an important dependence of the reaction mechanism evolution on the initial neutron richness of both projectile and target colliding nuclei. This suggests the role of the symmetry energy in the dynamical process.

On the basis of these results, it is suggested to use the capabilities of the new FraISe fragment separator to produce $^{68}$Ni and $^{56}$Ni beams using primary ones of $^{70}$Zn and $^{58}$Ni, respectively, at an incident energy of about 25 AMeV. This will increase the N/Z of the initial systems, for example, to study $^{68}$Ni+$^{124}$Sn (neutron-rich, N/Z = 1.46) and $^{56}$Ni+$^{112}$Sn (neutron-poor, N/Z = 1.15) (tag LNS-ND-HIC-c0 in Table 4). These asymmetries, wider than those used in the past, enhance the sensitivity to the symmetry energy
and put new severe constraints on the different transport codes. Anyway, in order to use FraISe beams to study reaction mechanisms that require high statistics, an intensity beam of at least 10⁶ pps is necessary.

Besides radioactive nuclei, great interest in the reaction dynamics community is oriented to the so-called metallic beams that are stable beams but with the possibility to have mixing of isospin in the entrance channel similar to the exotic ones, such as ⁹⁶Zr and ⁹⁶Ru. The study of systems like ⁹⁶Zr + ⁹⁶Zr (N/Z = 1.4) and ⁹⁶Ru + ⁹⁶Ru (N/Z=1.18)(tag LNS-ND-HIC-b0 in Table 4) and the respective projectile–target combinations should permit, in isobaric (no mass-size effects), symmetric (same Coulomb effect for target and projectile) systems, a precise disentangling of isospin diffusion and isospin migration in transport effects exploiting the differential motion of nucleons (protons and neutrons) through the neck. The production of these beams at LNS could be a new challenge due to their high fusion points.

### 3.1.4 Plans with CHIMERA and FARCOS devices in central collisions

The caloric curve that is the relation between the temperature and the excitation energy per nucleon is of fundamental relevance for many physical systems. The investigation of the dependence of the nuclear caloric curve on the neutron–proton asymmetry is particular interest. In fact, it has been demonstrated a clear mass dependence of the caloric curve for finite nuclei [89], while the dependence on the neutron/proton asymmetry, $(N-Z)/A$, remains uncertain due to conflicting different theoretical calculations and to a relatively small quantity of experimental data on the subject [90]. In addition, the available data show that the dependence of the caloric curve on the neutron–proton asymmetry depends on the reaction mechanism and collision dynamics [79]. These studies were begun by the ISODEC experiment [91] carried out at LNS with the CHIMERA detector. To extend the studies on this subject, it has been proposed to investigate the reactions ³⁴Ar + ⁵⁸Ni and ⁴⁶Ar + ⁶⁴Ni at energies between 15 and 30 AMeV, taking advantage of the FraISe beams and by using the 4π CHIMERA detector and the FARCOS correlator. For these reasons, the development of FraISe beams with A=30–70 is strongly supported for their relevance in order to further progress in this area of research (tag LNS-ND-HIC-c1 in Table 4).

In the past years, the limiting temperature for the formation of compound systems as a function of the isospin has been investigated at LNS. This work was pursued by looking to GDR $\gamma$ decay measurements [92] and by studying the competition between fusion-like and binary reactions by using the CHIMERA multidetector. It was pointed out that neutron-rich systems, formed for instance through ⁴⁸Ca + ⁴⁸Ca reactions, are able to produce a heavy residue (due to an incomplete fusion reaction), having a large temperature (over 5 MeV) and excitation energy (200–300 MeV), more efficiently than a neutron-poor system, such as the ⁴⁰Ca + ⁴⁰Ca [93, 94]. Predictions based on Constrained Molecular Dynamics calculations, CoMD-II [95], showed that the competition between fusion-like and binary reactions can constrain the parameterization of the symmetry energy. Thus, it has been proposed to use FraISe beams at energies around 20–30 AMeV. In this way, it will be possible to extend such investigations to further neutron-rich and neutron-poor systems beyond the stable beams used up to now. Secondary beams such as ³⁴Ar (neutron-poor) or ³⁸S (neutron-rich) could be produced from primary beams, respectively, of ³⁶Ar and ⁴⁰Ar (this last well studied and simulated within the FraISe project [16, 18]). The measurements will be performed with the CHIMERA multidetector. This adds the possibility to study these systems by detecting with the same device both the heavy residues and their GDR $\gamma$-decay (see Sect. 4.2.4 on new $\gamma$ detectors), thus probing that an equilibrated system is really formed.

### 3.1.5 Dynamical dipole and symmetry energy

In Sect. 4.2.2 an observable $D_a$ related to the dynamical dipole pre-equilibrium $\gamma$-ray emission is defined. The same observable was recently measured in mid-peripheral collisions induced on the system ⁴⁸Ca + ²⁷Al at 40 AMeV [96] and was constructed by using the charge and velocity of the emitted fragments and particles in quasi-complete events detected with the CHIMERA array.

This observable is closely linked to the charge/mass equilibration process in the reaction dynamics and almost independent of secondary decays. The reconstructed average dipolar signal has been reproduced through molecular dynamics CoMD-II calculations [95, 97]. These calculations show that this global observable is also capable to constrain the symmetry term of the EOS. In fact, a strong correlation was found between the experimental data and the symmetry energy written as $E_{sym}(\rho) = 12(\rho/\rho_0)^{2/3} + 20(\rho/\rho_0)^\gamma$, being $\gamma$ the stiffness parameter describing the potential term of the symmetry energy. As shown in Fig. 19, this comparison allowed us to establish a good agreement with experimental data for a stiffness parameter $\gamma = 1.06 \pm 0.16$, which corresponds to a $E_{sym} = 32$ MeV and a slope parameter $L = 87.6 \pm 14$ MeV.

In order to continue these studies, it has been proposed to use the new high-intensity SC stable beams (of the order of 10–20 nA) of Ar and Ca isotopes beams on Ca or Ni targets measuring $D_a$ in central or semi-central collisions (tag LNS-ND-HIC-b1 in Table 4). By using the CHIMERA array, we can detect, at the same time, charged particles in complete events and $\gamma$-rays (see Sect. 4.2.2 for other details).

### 3.1.6 Plans for neutron detection and new detection facilities

Neutron-rich high-intensity radioactive beams will allow us to study nuclear matter under extreme conditions, in terms of the isospin equilibration degree of freedom, both for long- and short-lived neutron-rich radioactive nuclei far from the stability valley. For
and put new severe constraints on the different transport codes. Anyway, in order to use FraISe beams to study reaction mechanisms that require high statistics, an intensity beam of at least $10^6$ pps is necessary.

Besides radioactive nuclei, great interest in the reaction dynamics community is oriented to the so-called metallic beams that are stable beams but with the possibility to have mixing of isospin in the entrance channel similar to the exotic ones, such as $^{96}$Zr and $^{96}$Ru. The study of systems like $^{96}$Zr + $^{96}$Zr ($N/Z = 1.4$) and $^{96}$Ru + $^{96}$Ru ($N/Z=1.18$)(tag LNS-ND-HIC-b0 in Table 4) and the respective projectile–target combinations should permit, in isobaric (no mass-size effects), symmetric (same Coulomb effect for target and projectile) systems, a precise disentangling of isospin diffusion and isospin migration in transport effects exploiting the differential motion of nucleons (protons and neutrons) through the neck. The production of these beams at LNS could be a new challenge due to their high fusion points.

### 3.1.4 Plans with CHIMERA and FARCOS devices in central collisions

The caloric curve that is the relation between the temperature and the excitation energy per nucleon is of fundamental relevance for many physical systems. The investigation of the dependence of the nuclear caloric curve on the neutron–proton asymmetry is particular interest. In fact, it has been demonstrated a clear mass dependence of the caloric curve for finite nuclei [89], while the dependence on the neutron/proton asymmetry, ($N-Z$)/A, remains uncertain due to conflicting different theoretical calculations and to a relatively small quantity of experimental data on the subject [90]. In addition, the available data show that the dependence of the caloric curve on the neutron–proton asymmetry depends on the reaction mechanism and collision dynamics [79]. These studies were begun by the ISODEC experiment [91] carried out at LNS with the CHIMERA detector. To extend the studies on this subject, it has been proposed to investigate the reactions $^{34}$Ar + $^{58}$Ni and $^{46}$Ar + $^{64}$Ni at energies between 15 and 30 AMeV, taking advantage of the FraISe beams and by using the $4\pi$ CHIMERA detector and the FARCOS correlator. For these reasons, the development of FraISe beams with $A=30–70$ is strongly supported for their relevance in order to further progress in this area of research (tag LNS-ND-HIC-c1 in Table 4).

In the past years, the limiting temperature for the formation of compound systems as a function of the isospin has been investigated at LNS. This work was pursued by looking to GDR $\gamma$ decay measurements [92] and by studying the competition between fusion-like and binary reactions by using the CHIMERA multidetector. It was pointed out that neutron-rich systems, formed for instance through $^{48}$Ca + $^{48}$Ca reactions, are able to produce a heavy residue (due to an incomplete fusion reaction), having a large temperature (over 5 MeV) and excitation energy (200–300 MeV), more efficiently than a neutron-poor system, such as the $^{40}$Ca + $^{40}$Ca [93, 94]. Predictions based on Constrained Molecular Dynamics calculations, CoMD-II [95], showed that the competition between fusion-like and binary reactions can constrain the parameterization of the symmetry energy. Thus, it has been proposed to use FraISe beams at energies around 20–30 AMeV. In this way, it will be possible to extend such investigations to further neutron-rich and neutron-poor systems beyond the stable beams used up to now. Secondary beams such as $^{34}$Ar (neutron-poor) or $^{38}$S (neutron-rich) could be produced from primary beams, respectively, of $^{36}$Ar and $^{40}$Ar (this last well studied and simulated within the FraISe project [16, 18]). The measurements will be performed with the CHIMERA multidetector. This adds the possibility to study these systems by detecting with the same device both the heavy residues and their GDR $\gamma$-decay (see Sect. 4.2.4 on new $\gamma$ detectors), thus probing that an equilibrated system is really formed.

### 3.1.5 Dynamical dipole and symmetry energy

In Sect. 4.2.2 an observable $D_a$ related to the dynamical dipole pre-equilibrium $\gamma$-ray emission is defined. The same observable was recently measured in mid-peripheral collisions induced on the system $^{48}$Ca + $^{27}$Al at 40 AMeV [96] and was constructed by using the charge and velocity of the emitted fragments and particles in quasi-complete events detected with the CHIMERA array.

This observable is closely linked to the charge/mass equilibration process in the reaction dynamics and almost independent of secondary decays. The reconstructed average dipolar signal has been reproduced through molecular dynamics CoMD-II calculations [95, 97]. These calculations show that this global observable is also capable to constrain the symmetry term of the EOS. In fact, a strong correlation was found between the experimental data and the symmetry energy written as $E_{sym}(\rho) = 12(\rho/\rho_0)^{2/3} + 20(\rho/\rho_0)^\gamma$, being $\gamma$ the stiffness parameter describing the potential term of the symmetry energy. As shown in Fig. 19, this comparison allowed us to establish a good agreement with experimental data for a stiffness parameter $\gamma = 1.06 \pm 0.16$, which corresponds to a $E_{sym} = 32$ MeV and a slope parameter $L = 87.6 \pm 14$ MeV.

In order to continue these studies, it has been proposed to use the new high-intensity SC stable beams (of the order of 10–20 nA) of Ar and Ca isotopes beams on Ca or Ni targets measuring $D_a$ in central or semi-central collisions (tag LNS-ND-HIC-b1 in Table 4). By using the CHIMERA array, we can detect, at the same time, charged particles in complete events and $\gamma$-rays (see Sect. 4.2.2 for other details).

### 3.1.6 Plans for neutron detection and new detection facilities

Neutron-rich high-intensity radioactive beams will allow us to study nuclear matter under extreme conditions, in terms of the isospin equilibration degree of freedom, both for long- and short-lived neutron-rich radioactive nuclei far from the stability valley. For
**Fig. 19** Adapted and modified from Ref. [96]: for the reaction $^{48}$Ca + $^{27}$Al the measured average dipolar signal $<D_a>$ is plotted as a function of charge Z of the detected fragments (red points). Horizontal bars in the data indicate that more than one charge have been added for a given point. Results are compared with the CoMD + GEMINI calculations for different shown values of the $\gamma$ parameter (lines) characterizing the isovectorial interaction. Grayed area contains the minimum and maximum values in the calculations in order to guide the eyes (see text and Ref. [96] for details)

<figure><img src="image_19.png" /></figure>

this reason it will be mandatory to detect neutrons as well as the charged particles; therefore, new devices have to be designed for future experiments. In fact, a correlator for neutrons and charged particles, i.e., a device able to detect neutrons with high angular and energy resolution, high granularity and with an acceptable neutron detection efficiency, will allow to study reaction dynamics and carry out nuclear spectroscopy also by using statistical techniques such as the intensity interferometry (HBT). New plastic scintillators materials, where neutron detection is based on the proton recoil technique, are nowadays under study to be used in new advanced compact devices. A starting point was the analysis of the performances of an EJ 299-33 scintillator, in high rate scattering experiments, performed with heavy-ion beams at LNS [98]. Studies for the construction of a prototype for such a device based on EJ-276G (green shifted version) plastic scintillators with SiPM readout are in progress [99, 100].

### 3.1.7 Plans with the FAZIA detector array

The FAZIA modular array [101] has been used in recent years for experiments in standalone mode at LNS and now at GANIL, coupled with INDRA $4\pi$ detector [102]. The telescopes are arranged in blocks of 16 and have as main characteristics the isotopic identification up to $Z \le 25$ with $\Delta E-E$ technique and $Z \approx 20$ via pulse shape analysis as shown, for example, in Fig. 4 of Ref. [2].

Besides the natural use of the existing local detectors like CHIMERA and FARCOS, it is proposed to complement the investigation at INFN-LNS also with experiments carried in a multipurpose large chamber substituting the big “CICLOPE” with one which is large enough to host the FAZIA array and new detector systems. These latter could be of composite and modular nature, since they aim at measuring different reaction probes (charge particles and $\gamma$-rays). More information can be found in the Sect. 4.2.4 dedicated to future experiments on GDR. The following items are suggested, mainly exploiting the enhanced isotopic identification capabilities of the FAZIA array:

(i) Advanced studies of the dynamical breakup of the projectile-like fragment. The measurement of the momenta of fully identified breakup pairs represents a powerful tool to strictly constrain sophisticated transport models (e.g., [103]), which up to now proved to be able to reproduce many features of the reactions. Detailed study of the (fast) breakup of medium-light excited PLF is important also to explore cluster correlations and their persistence at high energies. Reactions relevant for this point are $^{56}$Fe + X at 35 AMeV (X=$^{40}$Ca, $^{120}$Sn, $^{208}$Pb).

(ii) Toward a systematic knowledge of midvelocity emissions. It is proposed further investigation on the isotopic composition of all the ejectiles of dynamical origin, i.e., those related to midvelocity emission. In particular, a limited sensitivity to the symmetry energy parameterization has been observed in the relative yields of the most exotic midvelocity emitted IMFs (e.g., [77, 82, 104]). In future studies the absolute cross section of these emissions should be determined (so far, rare attempts on that exist) as a function of the energy and of the mass asymmetry of the interacting systems. Indeed, the studies of dynamical emission using neutron-deficient systems have been so far rather scarce, impeded by the rarity of energetic beams from in-flight fragmentation facilities and thus FraISe represents a good opportunity in this field. Relevant reaction beams could be neutron-poor Kr (including the stable $^{78}$Kr) or Ar beams (including the stable $^{36}$Ar) at 35 AMeV on targets $^{40}$Ca, $^{120}$Sn, $^{208}$Pb (tag LNS-ND-HIC-b2 in Table 4).

(iii) Toward a reconstruction of resonances. Useful information can also be gained looking at the excited IMFs reconstructed by means of the particle-fragment correlations and at the relative population of the excited levels. The use of particle correlations is an appealing method to backtrace from the detected fragments toward the primary configurations. It is clear that to fully exploit the isospin degree of freedom an experimental setup able to detect the mass of the ions in the widest possible range of charge is mandatory. At LNS the status-of-the-art for correlation techniques is represented by the FARCOS hodoscope based on Si-strip detectors and characterized by a very high granularity and energy resolution. In their typical operating geometry
**Fig. 19** Adapted and modified from Ref. [96]: for the reaction $^{48}$Ca + $^{27}$Al the measured average dipolar signal $<D_a>$ is plotted as a function of charge Z of the detected fragments (red points). Horizontal bars in the data indicate that more than one charge have been added for a given point. Results are compared with the CoMD + GEMINI calculations for different shown values of the $\gamma$ parameter (lines) characterizing the isovectorial interaction. Grayed area contains the minimum and maximum values in the calculations in order to guide the eyes (see text and Ref. [96] for details)

<figure><img src="image_19.png" /></figure>

this reason it will be mandatory to detect neutrons as well as the charged particles; therefore, new devices have to be designed for future experiments. In fact, a correlator for neutrons and charged particles, i.e., a device able to detect neutrons with high angular and energy resolution, high granularity and with an acceptable neutron detection efficiency, will allow to study reaction dynamics and carry out nuclear spectroscopy also by using statistical techniques such as the intensity interferometry (HBT). New plastic scintillators materials, where neutron detection is based on the proton recoil technique, are nowadays under study to be used in new advanced compact devices. A starting point was the analysis of the performances of an EJ 299-33 scintillator, in high rate scattering experiments, performed with heavy-ion beams at LNS [98]. Studies for the construction of a prototype for such a device based on EJ-276G (green shifted version) plastic scintillators with SiPM readout are in progress [99, 100].

### 3.1.7 Plans with the FAZIA detector array

The FAZIA modular array [101] has been used in recent years for experiments in standalone mode at LNS and now at GANIL, coupled with INDRA $4\pi$ detector [102]. The telescopes are arranged in blocks of 16 and have as main characteristics the isotopic identification up to $Z \le 25$ with $\Delta E-E$ technique and $Z \approx 20$ via pulse shape analysis as shown, for example, in Fig. 4 of Ref. [2].

Besides the natural use of the existing local detectors like CHIMERA and FARCOS, it is proposed to complement the investigation at INFN-LNS also with experiments carried in a multipurpose large chamber substituting the big “CICLOPE” with one which is large enough to host the FAZIA array and new detector systems. These latter could be of composite and modular nature, since they aim at measuring different reaction probes (charge particles and $\gamma$-rays). More information can be found in the Sect. 4.2.4 dedicated to future experiments on GDR. The following items are suggested, mainly exploiting the enhanced isotopic identification capabilities of the FAZIA array:

(i) Advanced studies of the dynamical breakup of the projectile-like fragment. The measurement of the momenta of fully identified breakup pairs represents a powerful tool to strictly constrain sophisticated transport models (e.g., [103]), which up to now proved to be able to reproduce many features of the reactions. Detailed study of the (fast) breakup of medium-light excited PLF is important also to explore cluster correlations and their persistence at high energies. Reactions relevant for this point are $^{56}$Fe + X at 35 AMeV (X=$^{40}$Ca, $^{120}$Sn, $^{208}$Pb).

(ii) Toward a systematic knowledge of midvelocity emissions. It is proposed further investigation on the isotopic composition of all the ejectiles of dynamical origin, i.e., those related to midvelocity emission. In particular, a limited sensitivity to the symmetry energy parameterization has been observed in the relative yields of the most exotic midvelocity emitted IMFs (e.g., [77, 82, 104]). In future studies the absolute cross section of these emissions should be determined (so far, rare attempts on that exist) as a function of the energy and of the mass asymmetry of the interacting systems. Indeed, the studies of dynamical emission using neutron-deficient systems have been so far rather scarce, impeded by the rarity of energetic beams from in-flight fragmentation facilities and thus FraISe represents a good opportunity in this field. Relevant reaction beams could be neutron-poor Kr (including the stable $^{78}$Kr) or Ar beams (including the stable $^{36}$Ar) at 35 AMeV on targets $^{40}$Ca, $^{120}$Sn, $^{208}$Pb (tag LNS-ND-HIC-b2 in Table 4).

(iii) Toward a reconstruction of resonances. Useful information can also be gained looking at the excited IMFs reconstructed by means of the particle-fragment correlations and at the relative population of the excited levels. The use of particle correlations is an appealing method to backtrace from the detected fragments toward the primary configurations. It is clear that to fully exploit the isospin degree of freedom an experimental setup able to detect the mass of the ions in the widest possible range of charge is mandatory. At LNS the status-of-the-art for correlation techniques is represented by the FARCOS hodoscope based on Si-strip detectors and characterized by a very high granularity and energy resolution. In their typical operating geometry
<figure><img src="image_20.png" /><figcaption>**Fig. 20** Sketch of the nuclear chart showing the various cluster configurations. See text for details</figcaption></figure>

(100 cm from the target), the FAZIA telescopes, with some modifications, should be also suitable for correlation studies [101, 105] allowing performances comparable to previous studies [106, 107]. Reactions relevant for this point are FraISe beams $^{15}$C, $^{14}$Be + $^{12}$C at 40 AMeV, $^{32,38}$S + $^{28}$Si at 40 AMeV.

(iv) Zero-degree configurations (i.e., modules with specific holding structure mounted at zero degree) can also be envisaged, provided that the beam currents can be properly reduced to safe values (typically below 1–2 kHz). Precise cross section measurements require a normalization to the known Rutherford cross section (by fast plastic scintillators located below the grazing angle) or a continuous monitoring of the beam current during the experiment. Relevant example reactions might be FraISe beams $^{15}$C, $^{14}$Be and $^{16,20}$O at 40 AMeV on $^{12}$C, $^{197}$Au targets (tag LNS-ND-HIC-c2 in Table 4).

## 3.2 Clustering

In light nuclei quantum mechanics plays a major role in creating special nuclear structures such as, nuclear skins and/or nuclear halos, nuclear clusters and molecules or gas condensate (see Fig. 20). The idea of clustering as an important phenomenon in describing structure of light nuclei is almost as old as the nuclear physics itself [108, 109], and the typical cluster is the $\alpha$ particle. The basic idea of clustering is that the interaction within the cluster is strong, while the clusters weakly interact with each other. Moreover, the threshold rule holds: cluster configurations in nuclei appears at excitation energies at, or above, the decay threshold into the cluster constituents. For this reason, only weakly bound nuclei, as for example $^{6,7}$Li and $^{9}$Be, possess cluster structures in their ground state, and for this reason ground state cluster configurations are more common in unstable nuclei. Among the different types of clustering, exotic or molecular clustering, may occur. In the exotic clustering the idea of a stiff particle as cluster is dropped. It can be, in fact, a soft particle easy to excite and to break. These configurations become more and more exotic when moving toward the drip line, e.g., [110].

In molecular clustering, clusters, typically $\alpha$s, are bound together by nucleons, which act as the electrons in covalent bonding of ordinary matter. Molecular linear-chain configurations are predicted to exist, as for example in $^{14}$C [111], by antisymmetrized molecular dynamics (AMD) (see Fig. 21). Associated to these configurations two bands are predicted [112], having the $\sigma$-bond or $\pi$-bond valence nucleons.

Molecular clustering could also be the result of the dynamics of the reaction. A molecule made of the two interacting nuclei may be formed during the collision; it rotates and then breaks up without the formation of a compound system. These resonances appear as broad peaks in the elastic channel excitation function having the angular distribution peaked at backward angles [113]. On the other hand, the dynamics of the reaction could be affected by the presence of clustering.