Aleksander Augustyn
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Aleksander Augustyn has a total of 77 co-authors. Here are the top co-authors by number of shared publications:
- Michał Kowal
National Centre for Nuclear Research
5 shared publications - Tomasz Cap
National Centre for Nuclear Research, Pasteura 7, 02-093 Warsaw, Poland
5 shared publications - Krzysztof Pomorski
National Centre for Nuclear Research
4 shared publications - Agnieszka Korgul
University of Warsaw
3 shared publications - Aleksandra Skruch
Faculty of Physics, University of Warsaw, Warsaw, Poland
3 shared publications - Chiara Mazzocchi
Faculty of Physics, University of Warsaw
3 shared publications
Latest Publications
- 13 October 2026
- Published by American Physical Society (APS) in Physical Review C
- Vol. 114 (4)
Comparative study of Langevin and random walk models for nuclear fission in the overdamped regime
- 13 October 2026
- Published by American Physical Society (APS) in Physical Review C
- Vol. 114 (4)
Comparative study of Langevin and random walk models for nuclear fission in the overdamped regime
- 24 August 2026
- Published by American Physical Society (APS) in Physical Review C
- Vol. 114 (2) , 024336
Survival of pairing correlations and shell effects at scission in finite-temperature nuclear fission: Implications for odd-even staggering
We investigate the finite-temperature evolution of microscopic free-energy corrections in nuclear fission, focusing on pairing and shell effects near scission. The analysis is based on a finite-temperature BCS treatment combined with the Strutinsky method and is performed for representative deformation points along the fission path. Both pairing and shell contributions exhibit regular thermal attenuation, but their deformation dependencies differ substantially. In particular, pairing remains strongly deformation dependent in the scission region, and its free-energy contribution differs markedly between the constant and surface-dependent pairing-strength prescriptions. The shell correction near scission is also significant at low temperature and is progressively suppressed with increasing excitation energy. These results support the interpretation of odd-even staggering in fragment charge yields as a manifestation of pairing correlations surviving into the strongly deformed prescission configuration. They also show that pairing and shell effects should be treated separately in finite-temperature dynamical calculations, with distinct deformation- and temperature-dependent attenuation laws.
- 24 August 2026
- Published by American Physical Society (APS) in Physical Review C
- Vol. 114 (2) , 024336
Survival of pairing correlations and shell effects at scission in finite-temperature nuclear fission: Implications for odd-even staggering
We investigate the finite-temperature evolution of microscopic free-energy corrections in nuclear fission, focusing on pairing and shell effects near scission. The analysis is based on a finite-temperature BCS treatment combined with the Strutinsky method and is performed for representative deformation points along the fission path. Both pairing and shell contributions exhibit regular thermal attenuation, but their deformation dependencies differ substantially. In particular, pairing remains strongly deformation dependent in the scission region, and its free-energy contribution differs markedly between the constant and surface-dependent pairing-strength prescriptions. The shell correction near scission is also significant at low temperature and is progressively suppressed with increasing excitation energy. These results support the interpretation of odd-even staggering in fragment charge yields as a manifestation of pairing correlations surviving into the strongly deformed prescission configuration. They also show that pairing and shell effects should be treated separately in finite-temperature dynamical calculations, with distinct deformation- and temperature-dependent attenuation laws.
- 7 July 2026
- Published by American Physical Society (APS) in Physical Review C
- Vol. 114 (1)
Isotope-resolved Ba and Xe yields in actinide fission and correlated heavy-light fragment systematics
- 7 July 2026
- Published by American Physical Society (APS) in Physical Review C
- Vol. 114 (1)
Isotope-resolved Ba and Xe yields in actinide fission and correlated heavy-light fragment systematics
- 27 May 2026
- Published by Springer Nature in Nature
- Vol. 654 (8117) , 52-56
Direct observation of the superallowed α-decay of 104Te
The radioactivity of the α particle is among the most compelling evidence for the existence of cluster structures in atomic nuclei. During the decay process, a pre-existing α particle tunnels through the potential barrier formed by the residual nucleus1,2. The degree of preformation of the α particle, a strongly bound system of two protons and two neutrons, is extracted from the data by dividing the α-decay probability by the barrier penetrability for a given particle energy. The preformation probability changes rapidly near nuclear shell closures, which is direct evidence that clustering is connected to nuclear structure3. Enhanced preformation was observed in the lightest α-particle emitters, spherical tellurium and xenon isotopes decaying to magic isotopes of tin. Here we show the most extreme case of α-particle preformation from the measurement of the decay of tellurium-104 (104Te). With a half-life of , 104Te is the fastest ground-state α-emitting nucleus known so far. The deduced preformation demonstrates that the enhancement is greater for 104Te than for any other nucleus. One nuclear model that can explain our observation postulates that the α particle can exist only in the low-nuclear-matter-density regions on the surface of the nucleus. The uniquely high preformation for 104Te is attributed to its relation to doubly magic tin-100 (100Sn), creating conditions conducive to form an α particle.- 27 May 2026
- Published by Springer Nature in Nature
- Vol. 654 (8117) , 52-56
Direct observation of the superallowed α-decay of 104Te
The radioactivity of the α particle is among the most compelling evidence for the existence of cluster structures in atomic nuclei. During the decay process, a pre-existing α particle tunnels through the potential barrier formed by the residual nucleus1,2. The degree of preformation of the α particle, a strongly bound system of two protons and two neutrons, is extracted from the data by dividing the α-decay probability by the barrier penetrability for a given particle energy. The preformation probability changes rapidly near nuclear shell closures, which is direct evidence that clustering is connected to nuclear structure3. Enhanced preformation was observed in the lightest α-particle emitters, spherical tellurium and xenon isotopes decaying to magic isotopes of tin. Here we show the most extreme case of α-particle preformation from the measurement of the decay of tellurium-104 (104Te). With a half-life of , 104Te is the fastest ground-state α-emitting nucleus known so far. The deduced preformation demonstrates that the enhancement is greater for 104Te than for any other nucleus. One nuclear model that can explain our observation postulates that the α particle can exist only in the low-nuclear-matter-density regions on the surface of the nucleus. The uniquely high preformation for 104Te is attributed to its relation to doubly magic tin-100 (100Sn), creating conditions conducive to form an α particle.- 4 March 2026
- Published by American Physical Society (APS) in Physical Review C
- Vol. 113 (3) , 034305
Static fission properties of even-even actinides within the Warsaw macroscopic-microscopic model using Fourier-over-spheroid parametrization
A systematic study of fission barrier heights and static properties of even-even actinide nuclei from Th to Cf has been performed within the Warsaw macroscopic-microscopic model using the five-dimensional Fourier-over-spheroid shape parametrization. The use of a large deformation grid, containing about $1.3\ifmmode\times\else\texttimes\fi{}{10}^{8}$ points for each nucleus, allows for a refined and numerically complete exploration of the potential-energy landscape without dividing the configuration space into subregions or applying interpolation. Barrier heights, extracted via the immersion water flow method, show good agreement with empirical evaluations (including the new IAEA RIPL-4 dataset) with mean deviations below 1 MeV. Special attention is given to the long-debated third, hyperdeformed minimum. For Th isotopes, a shallow but distinct third well appears, whereas it is absent in heavier actinides (U, Pu).- 4 March 2026
- Published by American Physical Society (APS) in Physical Review C
- Vol. 113 (3) , 034305
Static fission properties of even-even actinides within the Warsaw macroscopic-microscopic model using Fourier-over-spheroid parametrization
A systematic study of fission barrier heights and static properties of even-even actinide nuclei from Th to Cf has been performed within the Warsaw macroscopic-microscopic model using the five-dimensional Fourier-over-spheroid shape parametrization. The use of a large deformation grid, containing about $1.3\ifmmode\times\else\texttimes\fi{}{10}^{8}$ points for each nucleus, allows for a refined and numerically complete exploration of the potential-energy landscape without dividing the configuration space into subregions or applying interpolation. Barrier heights, extracted via the immersion water flow method, show good agreement with empirical evaluations (including the new IAEA RIPL-4 dataset) with mean deviations below 1 MeV. Special attention is given to the long-debated third, hyperdeformed minimum. For Th isotopes, a shallow but distinct third well appears, whereas it is absent in heavier actinides (U, Pu).- Open Access
- 17 November 2025
- Published by Springer Nature in Research Square
Direct observation of the superallowed α decay of 104Te
Alpha particle radioactivity is one of the most striking evidence for the existence of cluster structures in atomic nuclei. During the decay process, a preexisting α particle tunnels through the potential barrier formed by the residual nucleus [1,2]. The degree of preformation of the α particle, a strongly bound system of two protons and two neutrons, is extracted from the data by dividing the α-decay probability by the barrier penetrability for a given particle energy. The preformation probability changes rapidly near nuclear shell closures, which is direct evidence that clustering is connected to nuclear structure [3]. Enhanced preformation was observed in the lightest α-particle emitters, spherical tellurium and xenon isotopes decaying to magic isotopes of tin. Here, we show the most extreme case of α-particle preformation from the measurement of the decay of tellurium-104. With a half-life of 7.2 +2.3 -1.5 nanoseconds, tellurium-104 is the fastest ground state α-emitting nucleus known to date. The deduced preformation demonstrates that the enhancement is greater for tellurium-104 than for any other nucleus. One nuclear model that can explain our observation postulates that the α particle can exist only in the low nuclear matter density regions on the surface of the nucleus. The uniquely high preformation for tellurium-104 is attributed to its relation to doubly-magic tin-100, creating conditions conducive to form an α particle.
- 17 November 2025
- Published by Springer Nature in Research Square
Open AccessDirect observation of the superallowed α decay of 104Te
Alpha particle radioactivity is one of the most striking evidence for the existence of cluster structures in atomic nuclei. During the decay process, a preexisting α particle tunnels through the potential barrier formed by the residual nucleus [1,2]. The degree of preformation of the α particle, a strongly bound system of two protons and two neutrons, is extracted from the data by dividing the α-decay probability by the barrier penetrability for a given particle energy. The preformation probability changes rapidly near nuclear shell closures, which is direct evidence that clustering is connected to nuclear structure [3]. Enhanced preformation was observed in the lightest α-particle emitters, spherical tellurium and xenon isotopes decaying to magic isotopes of tin. Here, we show the most extreme case of α-particle preformation from the measurement of the decay of tellurium-104. With a half-life of 7.2 +2.3 -1.5 nanoseconds, tellurium-104 is the fastest ground state α-emitting nucleus known to date. The deduced preformation demonstrates that the enhancement is greater for tellurium-104 than for any other nucleus. One nuclear model that can explain our observation postulates that the α particle can exist only in the low nuclear matter density regions on the surface of the nucleus. The uniquely high preformation for tellurium-104 is attributed to its relation to doubly-magic tin-100, creating conditions conducive to form an α particle.
- 28 June 2024
- Published by American Physical Society (APS) in Physical Review C
- Vol. 109 (6) , L061603
Dipole-driven multidimensional fusion: An insightful approach to the formation of superheavy nuclei
We present an approach to describe the fusion of two heavy ions in which the colliding system has access to a wide spectrum of shapes through the utilization of an auxiliary reference frame and the employment of a multipole expansion of the nuclear radius with the dipole term treated as an actual and leading shape variable. Access to fusion shapes that would otherwise be unattainable is possible by initially placing the origin of the auxiliary reference frame in the neck region between the colliding nuclei. The fusion process is modeled as an unconstrained biased random walk in a four-dimensional deformation space with step probabilities correlated to the density of available states. Deformation energy is calculated using the macroscopic-microscopic method, incorporating rotational energy. The presented approach successfully describes fusion probabilities for reactions involving , and projectiles with a target.- 28 June 2024
- Published by American Physical Society (APS) in Physical Review C
- Vol. 109 (6) , L061603
Dipole-driven multidimensional fusion: An insightful approach to the formation of superheavy nuclei
We present an approach to describe the fusion of two heavy ions in which the colliding system has access to a wide spectrum of shapes through the utilization of an auxiliary reference frame and the employment of a multipole expansion of the nuclear radius with the dipole term treated as an actual and leading shape variable. Access to fusion shapes that would otherwise be unattainable is possible by initially placing the origin of the auxiliary reference frame in the neck region between the colliding nuclei. The fusion process is modeled as an unconstrained biased random walk in a four-dimensional deformation space with step probabilities correlated to the density of available states. Deformation energy is calculated using the macroscopic-microscopic method, incorporating rotational energy. The presented approach successfully describes fusion probabilities for reactions involving , and projectiles with a target.