An asymmetric fission island driven by shell effects in light fragments
Journal article, 2025
Nuclear fission leads to the splitting of a nucleus into two fragments1,2. Studying the distribution of the masses and charges of the fragments is essential for establishing the fission mechanisms and refining the theoretical models3,4. It has value for our understanding of r-process nucleosynthesis5,6, in which the fission of nuclei with extreme neutron-to-proton ratios is pivotal for determining astrophysical abundances and understanding the origin of the elements7 and for energy applications8,9. Although the asymmetric distribution of fragments is well understood for actinides (elements in the periodic table with atomic numbers from 89 to 103) based on shell effects10, symmetric fission governs the scission process for lighter elements. However, unexpected asymmetric splits have been observed in neutron-deficient exotic nuclei11, prompting extensive further investigations. Here we present measurements of the charge distributions of fission fragments for 100 exotic fissioning systems, 75 of which have never been measured, and establish a connection between the neutron-deficient sub-lead region and the well-understood actinide region. These new data comprehensively map the asymmetric fission island and provide clear evidence for the role played by the deformed Z = 36 proton shell of the light fragment in the fission of sub-lead nuclei. Our dataset will help constrain the fission models used to estimate the fission properties of nuclei with extreme neutron-to-proton ratios for which experimental data are unavailable.
Author
P. Morfouace
The French Alternative Energies and Atomic Energy Commission (CEA)
J. Taieb
The French Alternative Energies and Atomic Energy Commission (CEA)
A. Chatillon
The French Alternative Energies and Atomic Energy Commission (CEA)
L. Audouin
University Paris-Saclay
G. Blanchon
The French Alternative Energies and Atomic Energy Commission (CEA)
R.N. Bernard
The French Alternative Energies and Atomic Energy Commission (CEA)
N. Dubray
The French Alternative Energies and Atomic Energy Commission (CEA)
N. Pillet
The French Alternative Energies and Atomic Energy Commission (CEA)
D. Regnier
The French Alternative Energies and Atomic Energy Commission (CEA)
H. Alvarez-Pol
Universidade de Santiagode Compostela
F. Amjad
Helmholtz Association of German Research Centres
P. André
Institut de Recherche sur les Lois Fondamentales de l'Univers
G. Authelet
Institut de Recherche sur les Lois Fondamentales de l'Univers
L. Atar
Technische Universität Darmstadt
T. Aumann
Helmholtz Association of German Research Centres
J. Benlliure
Universitat de Valencia
K. Boretzky
Helmholtz Association of German Research Centres
Lukas Bott
Goethe University Frankfurt
T. Brecelj
Jozef Stefan Institute
C. Caesar
Helmholtz Association of German Research Centres
P. Carpentier
The French Alternative Energies and Atomic Energy Commission (CEA)
E. Casarejos
University of Vigo
J. Cederkall
Lund University
A. Corsi
Institut de Recherche sur les Lois Fondamentales de l'Univers
D. Cortina-Gil
Universitat de Valencia
A. Cvetinović
Jozef Stefan Institute
E. De Filippo
National Institute for Nuclear Physics
T. Dickel
Helmholtz Association of German Research Centres
M. Feijoo
Universidade de Santiagode Compostela
L. M. Fonseca
Helmholtz Association of German Research Centres
D. Galaviz
LIP - Lisboa
G. García-Jiménez
Universidade de Santiagode Compostela
I. Gasparic
Ruder Boskovic Institute
E. Geraci
National Institute for Nuclear Physics
R. Gernhäuser
Technical University of Munich
B. Gnoffo
National Institute for Nuclear Physics
K. Gobel
Goethe University Frankfurt
A. Graña-González
Universidade de Santiagode Compostela
E. Haettner
Helmholtz Association of German Research Centres
A. L. Hartig
Technische Universität Darmstadt
M. Heil
Helmholtz Association of German Research Centres
Andreas Heinz
Subatomic, High Energy and Plasma Physics
Thomas Hensel
Helmholtz Association of German Research Centres
Matthias Holl
Chalmers, Physics, Subatomic, High Energy and Plasma Physics
C. Hornung
Helmholtz Association of German Research Centres
A. Horvat
Technische Universität Darmstadt
A. Jedele
Helmholtz Association of German Research Centres
D. Jelavić Malenica
Ruder Boskovic Institute
T. Jenegger
Technical University of Munich
L. Ji
Technische Universität Darmstadt
Håkan T Johansson
Subatomic, High Energy and Plasma Physics
Björn Jonson
Subatomic, High Energy and Plasma Physics
B. Jurado
University of Bordeaux
N. Kalantar-Nayestanaki
University of Groningen
E. Kazantseva
Helmholtz Association of German Research Centres
A. Kelić-Heil
Helmholtz Association of German Research Centres
O. Kiselev
Helmholtz Association of German Research Centres
P. Klenze
Technical University of Munich
R. Knobel
Helmholtz Association of German Research Centres
D. Körper
Helmholtz Association of German Research Centres
D. Kostyleva
Helmholtz Association of German Research Centres
T. Kröll
Technische Universität Darmstadt
N. Kuzminchuk
Helmholtz Association of German Research Centres
B. Laurent
The French Alternative Energies and Atomic Energy Commission (CEA)
I. Lihtar
Ruder Boskovic Institute
Y. Litvinov
Helmholtz Association of German Research Centres
B. Loher
Helmholtz Association of German Research Centres
N. S. Martorana
National Institute for Nuclear Physics
B. Mauss
The French Alternative Energies and Atomic Energy Commission (CEA)
Silvia Murillo Morales
University of York
D. Mücher
University of Guelph
I. G. Mukha
Helmholtz Association of German Research Centres
E. Nacher
Universitat de Valencia
A. Obertelli
Technische Universität Darmstadt
E. V. Pagano
INFN - Laboratori Nazionali del Sud
V. Panin
Helmholtz Association of German Research Centres
J. Park
Institute for Basic Science
S. Paschalis
University of York
M. Petri
University of York
S. Pietri
Helmholtz Association of German Research Centres
S. Pirrone
National Institute for Nuclear Physics
G. Politi
National Institute for Nuclear Physics
L. Ponnath
Technische Universität Darmstadt
A. Revel
Institut de Recherche sur les Lois Fondamentales de l'Univers
H. B. Rhee
Technische Universität Darmstadt
J. L. Rodriguez-Sanchez
Universidade de Santiagode Compostela
L. Rose
University of York
D. Rossi
Helmholtz Association of German Research Centres
P. Roy
Helmholtz Association of German Research Centres
P. Russotto
INFN - Laboratori Nazionali del Sud
C. Scheidenberger
Helmholtz Association of German Research Centres
H. Scheit
Technische Universität Darmstadt
H. Simon
Helmholtz Association of German Research Centres
S. Storck-Dutine
Technische Universität Darmstadt
A. Stott
University of York
Y. Sun
Technische Universität Darmstadt
Christian Sürder
Technische Universität Darmstadt
Y. K. Tanaka
Helmholtz Association of German Research Centres
R. Taniuchi
University of York
O. Tengblad
Spanish National Research Council (CSIC)
I. Tisma
Jozef Stefan Institute
Hans Törnqvist
Helmholtz Association of German Research Centres
M. Trimarchi
National Institute for Nuclear Physics
S. Velardita
Technische Universität Darmstadt
J. Vesic
Jozef Stefan Institute
B. Voss
Helmholtz Association of German Research Centres
F. Wamers
Helmholtz Association of German Research Centres
H. Weick
Helmholtz Association of German Research Centres
F. Wienholtz
Technische Universität Darmstadt
J. Zhao
Helmholtz Association of German Research Centres
Mikhail Zhukov
Chalmers, Physics
Nature
0028-0836 (ISSN) 1476-4687 (eISSN)
Vol. In Press 339-344 78Subject Categories (SSIF 2025)
Subatomic Physics
DOI
10.1038/s41586-025-08882-7