Production of neutron rich nuclei of the Terra

Production of neutron -rich nuclei of the Terra Incognita Daniele Quero Dipartimento di Fisica “Ettore Pancini”, Università degli Studi di Napoli Federico II INFN, Sezione di Napoli

Why to produce neutron-rich nuclei… • Link to the search of the Island of Stability! • Rank 3 in “The 11 Greatest Unanswered Questions of Physics”: How were the heavy elements from iron to uranium made? What is still unknown about the r-process? • Nuclear Structure: quenching of shell closure in nuclei with large neutron excess Terzo Incontro Nazionale INFN 2016 - Frascati Daniele Quero

Cold-Fusion Multinucleon Transfer Hot-Fusion n-capture Courtesy of Yuri Oganessian Terzo Incontro Nazionale INFN 2016 - Frascati Daniele Quero

Exploring the Segré Chart • Proton-rich: Fusion reactions ~7000 Nuclei ~3000 Known Nuclei ~290 Nuclei in Nature • Medium-havy neutron-rich: Fission, ISOL and In -Flight techn. Island of Stability Stable Nuclei Radioactive Nuclei Unknown Nuclei Terzo Incontro Nazionale INFN 2016 - Frascati • Heavy and superheavy neutron-rich: Fusion reactions with radioactive beams? neutron capture? multinucleon transfer reactions? Daniele Quero

Choice of Observables Shell Effects in exit channel [1] V. Zagrebaev, W. Greiner, J. Phys. G: Nucl. Part. Phys. 31 (2005) 825. Terzo Incontro Nazionale INFN 2016 - Frascati

Multinucleon Transfer Reactions Collective Do. F • Vi scosity: E ner gy dissip at ion a nd e xchan ge bet ween Collective Do. F a n d The rmal B ath • The i nt era ction pot entia l surfa ce[1] depen ds on t he collectiv e Do. F: e long at ion, ma ss asymmetr y, nuclear o rien tat ion, deforma tion… Thermal Bath (Single Particle Do. F) Friction • Time evo lut io n : Lange vin Eq uations [2] V. A. Zagrebaev and W. Greiner, J. Phys G 35, 125103 (2008) Terzo Incontro Nazionale INFN 2016 - Frascati Daniele Quero

Prediction of the Model 238 U + 248 Cm @ 750 Me. V Super-Heavy Region [3] V. Zagrebaev and W. Greiner, PRC 83 044618 (2011) Terzo Incontro Nazionale INFN 2016 - Frascati Daniele Quero

How to explore the shell N = 126 • 202 Os ta i n g o c n I a rr e T [2] V. A. Zagrebaev and W. Greiner, J. Phys G 35, 125103 (2008) Terzo Incontro Nazionale INFN 2016 - Frascati Daniele Quero

A simple Mass Spectrometer Fragment trajectory Wha t do we ne ed: • Time of Flight • E ner g y an d M oment um Con ser vat io n L a w Start Stop TARGET Fragment trajectory Terzo Incontro Nazionale INFN 2016 - Frascati Daniele Quero

PRISMA setup @ LNL • Fr ag ments Ma ss Spe ct rum v ia TO F -TOF Ana lysis • Z ident ificat ion by o ΔE-E Telescope-like Ionization Chamber Matrix o Bragg Peak Analysis o Trajectory evaluation in magnetic fields Terzo Incontro Nazionale INFN 2016 - Frascati Daniele Quero

Terzo Incontro Nazionale INFN 2016 - Frascati Daniele Quero

Xe + Pb @LNL: Preliminary Results 106 105 104 Xe Pb 102 101 100 120 140 200 220 240 Terzo Incontro Nazionale INFN 2016 - Frascati Daniele Quero

Conclusions… Exploring the “Terra Incognita” by the Multi-Nucleon Transfer • Persistence of shell closures at N=82 and N= 126 in neutronrich zone • Possible production of nuclei of the Terra incognita • Possible production of nuclei of interest for the r-process • Xe + Pb results pave the way to the production of nuclei in the super-heavy region Terzo Incontro Nazionale INFN 2016 - Frascati Daniele Quero

…and Perspectives • Z evaluation pursuable by means of different exp. techniques: o Kinematics-Killing (β-γ coincidence in fragment decay) o Non-Killing (PRISMA trajectories, Bragg Chambers…) • Extend the study to N=28 – 82 • Neutron-rich nuclei beams to further exploit the potential of Multi Nucleon Transfer Terzo Incontro Nazionale INFN 2016 - Frascati Daniele Quero

Thanks for the attention D. Quero 1, E. Vardaci 1, L. Corradi 2 , E. Fioretto 2, E. M. Kozulin 3, V. A. Zagrebaev 3, I. M. Itkis 3, G. Knyazheva 3, K. Novikov 3 1 Dipartimento di Fisica “E. Pancini”, Università degli Studi di Napoli and INFN Sezione di Napoli, Italy 2 Laboratori Nazionali di Legnaro, Legnaro (PD), Italy 3 FLNR, Joint Institute for Nuclear Research, Dubna, Russia

Terzo Incontro Nazionale INFN 2016 - Frascati Daniele Quero

Terzo Incontro Nazionale INFN 2016 - Frascati Daniele Quero

The understanding of the r-process • Neutron capture followed by β-decay • Intense neutron fluxes: capture is much faster than β-decay… untill a waiting point is reached! • Possible settings: neutron stars, type II supernovae • Waiting point = neutron shell closure: last known is N=126, deeply in the Terra Incognita • It is mandatory to study the neutron-rich nuclei produced along the path but available neutron fluxes are insufficient to repeat the process in lab Terzo Incontro Nazionale INFN 2016 - Frascati Daniele Quero

0 1µs 1 s 5 1 h 10 15 Log. T 1/2 s 1 My 1 y 120 Proton number -5 110 100 90 80 70 100 110 120 150 130 140 160 Neutron number 170 Terzo Incontro Nazionale INFN 2016 - Frascati 180 190 Daniele Quero

Terzo Incontro Nazionale INFN 2016 - Frascati Daniele Quero

Terzo Incontro Nazionale INFN 2016 - Frascati Daniele Quero

Terzo Incontro Nazionale INFN 2016 - Frascati Daniele Quero

Terzo Incontro Nazionale INFN 2016 - Frascati Daniele Quero

Terzo Incontro Nazionale INFN 2016 - Frascati Daniele Quero

Z= 60 Xe Z= 54