Proceedings Series


Vol. 16 (2023), No. 4, 41 Articles

Zakopane Conference on Nuclear Physics Extremes of the Nuclear Landscape

Zakopane, Poland; August 28–September 4, 2022

Front Matter

Conference PhotoPoster


Preface


Conference Program


Nuclear Equation of State from Nuclear Collective Excited State Properties

abstract

In this work, I present a personal overview of recent investigations of overall properties in Giant Resonances that impact our understanding of the nuclear Equation of State around saturation density.


Isospin Mixing: Recent Results and Future Plans

abstract

The value of isospin mixing at zero temperature was recently deduced in the mass region of \(60 \leq A \leq 80\). The measured values have been obtained using both fusion–evaporation reactions and exploiting the selection rules for the emission of electric dipole radiation in \(N=Z\) nuclei. The strength of the \(\gamma \)-decay of the IVGDR provides the starting point for the determination of the value of the isospin mixing probability \(\alpha ^2\). This quantity is expected to decrease when the excitation energy increases. In this contribution, the phenomenon of isospin mixing will be discussed, the measurements of isospin mixing in \(^{80}\)Zr and \(^{60}\)Zn, using the IVGDR technique, will be summarized, some very preliminary data on \(^{72}\)Kr will be presented, and some perspectives will be given.


all authors

M. Ciemała, M. Kmiecik, A. Maj, B. Fornal, P. Bednarczyk, N. Cieplicka-Oryńczak, Ł.W. Iskra, M. Matejska-Minda, K. Mazurek, B. Wasilewska, M. Ziębliński, F.C.L. Crespi, A. Bracco, S. Bottoni, F. Camera, S. Leoni, G. Benzoni, B. Million, O. Wieland, S. Brambilla, J. Wilson, I. Matea, M. Lebois, N. Jovančević, O. Dorvaux, Ch. Schmitt, J. Dudek, S. Kihel, P.J. Napiorkowski, M. Kicińska-Habior, I. Mazumdar, V. Nanal

Feeding of the Residual States with GDR gamma Decay Studied by nuBall Coupled with PARIS

abstract

In the paper, experimental results of high-energy gamma GDR (Giant Dipole Resonance) decay from the \(^{192}\)Pt compound nucleus associated with the \(4n\) decay channel leading to the \(^{188}\)Pt evaporation residue are presented. The measurement, which was performed with the use of coupled nuBall and PARIS arrays, aimed to investigate the link between deformation of a hot nucleus and different deformations of the residual states. The high-energy gamma rays from the GDR decay measured using the PARIS phoswiches provided information on compound nucleus properties, particularly on its effective shape. Discrete transitions in evaporation residues, measured by the nuBall array, were used to select the final products of specific deformations. As a result, the GDR strength functions measured for the particular decay paths were obtained.


all authors

N. Cieplicka-Oryńczak, B. Fornal, M. Ciemała, M. Kmiecik, A. Maj, J. Łukasik, P. Pawłowski, B. Sowicki, B. Wasilewska, M. Ziębliński, P. Bednarczyk, I. Ciepał, K. Dhanmeher, J. Grębosz, Ł.W. Iskra, M. Krzysiek, M. Matejska-Minda, K. Mazurek, W. Parol, B. Włoch, C. Boiano, S. Brambilla, B. Million, Y. Jaganathen, M. Płoszajczak, I. Burducea, C. Clisu, N. Florea, D.A. Iancu, N. Marginean, R. Marginean, L. Stan, M.N. Harakeh, P. Kulessa, I. Matea, M. Sferrazza

M4 Resonances in Light Nuclei Studied at CCB

abstract

M4 resonances in light nuclei result from the \(p_{3/2} \rightarrow d_{5/2}\) stretched excitations. Their configurations should be relatively simple, which makes them good benchmarks for the theoretical calculations taking into account the role of continuum couplings. The first experimental studies aiming at tracing the decay of the M4 stretched resonance in \(^{13}\)C, located at 21.47 MeV, were undertaken at the Cyclotron Centre Bronowice at the Institute of Nuclear Physics Polish Academy of Sciences in Kraków, Poland (IFJ PAN). They provided information on the proton and neutron decay channels of this resonance to \(^{12}\)B and \(^{12}\)C daughter nuclei, respectively. These experimental results were then compared with the theoretical calculations based on the Gamow Shell Model approach, in terms of energy, width, and in particular, the decay pattern. Furthermore, the studies of the next cases, namely, \(^{14}\)N and \(^{16}\)O, where several M4 resonances appear at around 20 MeV, have been recently performed at CCB. The new experimental findings will serve as a testing ground for future calculations describing the heavier nuclei in this important region of the nuclear chart.


Evolution of the Pygmy Dipole Resonance in Sn Isotopes

abstract

The \(^{111-113,116-122,124}\)Sn isotopes were studied in light-particle-induced reactions to obtain the low-lying \(\gamma \)-ray strength functions (GSFs) with the Oslo method. These data were further combined with the inelastic relativistic proton scattering GSFs to study the evolution of the pygmy dipole resonance (PDR) with an increasing neutron number. The PDR was found to be centered at \(\approx 8\) MeV in all isotopes. The fraction of the energy-weighted sum rule for dipole transitions exhausted by the PDR in these isotopes ranges from \(\approx 1.5\)% to \(3\)%, being the maximum for \(^{120}\)Sn.


all authors

V. Ranga, I. Mazumdar, S.P. Weppner, S. Panwar, R. Sariyal, S.M. Patel, P.B. Chavan, A.K. Rhine Kumar, G. Anil Kumar

Measurements of Absolute \(\gamma \)-ray Cross Sections for \(^{16}\)O\((p,p^\prime \gamma )^{16}\)O Reaction

abstract

We report on the results of our measurements of \(\gamma \)-ray cross sections from the inelastic scattering of protons from \(^{16}\)O in the energy range of 8–16 MeV. The absolute cross sections were measured for the \(\gamma \)-rays of energy 6.13, 6.92, and 7.12 MeV. Angular distribution was measured at seven angles at a proton beam energy of 9 MeV. This work reports on the first measurement of absolute cross section for 6.92 MeV \(\gamma \)-ray in this energy region. Such cross-section measurements provide important data for \(\gamma \)-ray astronomy and material analysis techniques. A phenomenological optical model potential (OMP) was set up to analyse the results of our measurements. Such OMP calculations have challenged theorists in this target mass and projectile-energy range. The challenge stems from the increased contribution of nuclear structure effects for low-mass target nuclei. We have tried to tackle this problem by including many low-energy resonances and target deformation effects. We optimised the OMP parameters by fitting a large body of available experimental data. The target deformation parameter plays a crucial role in understanding the overall dynamics of the reaction.


Constraints on Neutron-star Radii from Laboratory Experiments

abstract

High-precision measurements of asymmetry in parity-violating electron–nuclei scattering experiments enhance our understanding of the structure of nuclei and neutron stars. PREX-\(2\) and CREX (Lead/Calcium Radius Experiments) are two recent experiments conducted at JLab in Newport News, Virginia, USA, by elastically scattering an electron beam with rapidly flipping helicity from \(^{208}\)Pb and \(^{48}\)Ca targets, respectively. PREX-\(2\) measured an asymmetry \(A_{\mathrm {PV}}^{208}=550\pm 16~{\mathrm {[stat.]}} \pm 8~{\mathrm {[sys.]}}\) ppb at kinematics with mean \(Q^2 \sim 0.00616\) GeV\(^2\). Together with the predecessor PREX-\(1\), it constrained the \(^{208}\)Pb neutron skin to \(R_{\mathrm {skin}}^{208}=0.283 \pm 0.071\) fm. The combined constraint on nuclear DFT models from PREX and the NICER telescope neutron-star radii measurements is in \(\sim 1\) standard deviation tension with the constraint from the LIGO tidal deformability measurements. CREX was conducted at kinematics with mean \(Q^2 \sim 0.0297\) GeV\(^2\), resulting in an asymmetry \(A_\mathrm {PV}^{48}=2668\pm 106~{\mathrm {[stat.]}} \pm 40~{\mathrm {[sys.]}}\) ppb and the \(^{48}\)Ca neutron skin \(R_{\mathrm {skin}}^{48}=0.121 \pm 0.026~{\mathrm {[exp.]}} \pm 0.024~{\mathrm {[model]}}\) fm respectively. The CREX result contrasts the PREX result by predicting a thinner neutron skin for medium-mass nuclei compared to heavy nuclei. Understanding these anomalies with further studies is necessary to pin down the density-dependence of nuclear symmetry energy and constrain neutron-star radii accurately.


all authors

A. Vitéz-Sveiczer, S. Kovács, G.G. Kiss, Y. Saito, A. Tarifeño-Saldivia, M. Pallas, J.L. Tain, I. Dillmann, J. Agramunt, A. Algora, C. Domingo-Pardo, A. Estrade, C. Appleton, J.M. Allmond, P. Aguilera, H. Baba, N.T. Brewer, C. Bruno, R. Caballero-Folch, F. Calvino, P.J. Coleman-Smith, G. Cortes, T. Davinson, N. Fukuda, Z. Ge, S. Go, C.J. Griffin, R.K. Grzywacz, O. Hall, A. Horváth, J. Ha, L.J. Harkness-Brennan, T. Isobe, D. Kahl, T.T. King, A. Korgul, R. Krücken, S. Kubono, M. Labiche, J. Liu, J. Liang, M. Madurga, K. Miernik, F. Molina, A.I. Morales, M.R. Mumpower, E. Nacher, A. Navarro, N. Nepal, S. Nishimura, M. Piersa-Siłkowska, V. Phong, B.C. Rasco, B. Rubio, K.P. Rykaczewski, J. Romero-Barrientos, H. Sakurai, L. Sexton, Y. Shimizu, M. Singh, T. Sprouse, T. Sumikama, R. Surman, H. Suzuki, T.N. Szegedi, H. Takeda, A. Tolosa-Delgado, K. Wang, M. Wolinska-Cichocka, P. Woods, R. Yokoyama, Z. Xu

Half-life Measurement Using Implant-\((\beta -\gamma )\) Time Correlations in the Region of Neutron-rich Lanthanides

abstract

Neutron-rich lanthanides were produced via in-flight fission of a \(^{238}\)U primary beam at the RIBF, RIKEN Nishina Center to measure half-lives (\(T_{1/2}\)) and beta-delayed neutron emission probabilities (\(P_n\)) in order to constrain r-process abundance calculations. \(^{159\text {--}166}\)Pm, \(^{161\text {--}168}\)Sm, \(^{165\text {--}170}\)Eu, and \(^{167\text {--}172}\)Gd ions were implanted in the Advanced Implantation Detector Array (AIDA), and \(\beta \)-delayed neutrons and \(\gamma \)-rays were detected by the surrounding detector array (BRIKEN). For the validation of \(T_{1/2}\) values derived from implantation–\(\beta \) (i–\(\beta \)) time correlations, \(\gamma \)-spectroscopic methods were used as well. The experimental results of the \(\beta \)-delayed \(\gamma \)‑spectroscopy of \(^{162}\)Pm are presented here as an example. A half-life value from \(\gamma \)-decay curves was derived with a comparable uncertainty to the result from the i–\(\beta \) method, and a mean value well within the 1\(\sigma \) range.


Nuclear Isomers in the Heaviest Nuclei — the Odd Nucleon as a Sensitive Probe of Low-lying Nuclear Structure

abstract

After the discovery of superheavy nuclei up to \(^{294}\)Og and with the advent of new high-intensity accelerator facilities, more and more details of the nuclear structure of those exotic nuclear systems become accessible. In particular, nuclear structure studies in the vicinity of the deformed shell gaps in the nobelium/fermium region, which were already at the focus of the existing facilities throughout the last two decades, can be extended to a substantially more detailed level. In particular, decay spectroscopy of nuclei with odd particle numbers, which was hitherto hampered by limited beam intensities, will profit from the capabilities of the new facilities. This paper presents some results accumulated for odd-particle (super)heavy nuclei and gives an outlook on research opportunities at future facilities like SPIRAL2 at GANIL. Owing much of my knowledge and scientific passion to one of the main players in the field of superheavy nuclei, Sigurd Hofmann who left us in June 2022, I dedicate my presentation and this article to honor him, his scientific achievements, and his memory.


Facility Upgrade for SHE Research at RIKEN Nishina Center

abstract

In 2016, the RIKEN Nishina Center (RNC) commenced a new comprehensive superheavy element (SHE) research program, the “SHE project”. The project aimed at synthesizing a new superheavy element, \(Z=119\), through a hot fusion reaction \(^{51}\mathrm {V} + ^{248}\)Cm constructing a superconducting RIKEN linear accelerator (SRILAC) and a new superconducting electron-cyclotron-resonance ion source (SC-ECRIS) to boost the final energy and intensity. A gas-filled recoil ion separator (GARIS-III) suitable for detecting the residues of the hot-fusion reaction was also constructed. The SHE project and its commissioning results are briefly described.


all authors

A. Utepov, D. Ackermann, C. Stodel, A. Lemasson, D. Ramos, M. Rejmund, E. Clement, B. Jacquot, J. Piot, J.E. Ducret, L. Caceres, H. Savajols, R. Chakma, S. Heinz, B. Kindler, B. Lommel, A. Korichi, A. Lopez-Martens, K. Hauschild, B. Sulignano, C. Theisen, M. Vandebrouck, E. Rey-Herme, A. Gadea, L. Corradi, E. Fioretto, F. Galtarossa, S. Szilner, T. Mijatović, C. Fougères, D. Seweryniak, Y.H. Kim, Y. Cho, Y. Son, M. Matejska-Minda, O. Dorvaux, M. Forge, K. Kessaci, B. Gall, P. Marini, B. Million

Multinucleon Transfer Reactions in the \(^{238}\mathrm {U}+{^{238}}\)U System Studied with the VAMOS\(+\)AGATA\(+\)ID-Fix

abstract

The measurement of the production cross sections of exotic neutron-rich heavy nuclei, in the uranium region, in the vicinity of the \(N = 152\) deformed shell gap was carried out via multinucleon transfer reactions of \(^{238}\mathrm {U} + {^{238}}\)U at 7.193 and 6.765 MeV/\(A\) using the VAMOS\(++\) magnetic spectrometer coupled to the AGATA and ID-Fix photon detection arrays. This article reports on the status of the VAMOS\(++\) data analysis and results on the population of the strongest (\(\pm 1n\)) transfer channels observed from the decay of long-lived products after irradiation.


all authors

J. Romero, K. Auranen, M. Block, A.D. Briscoe, T. Eronen, W. Gins, T. Grahn, P.T. Greenlees, A. Illana, R. Julin, H. Joukainen, H. Jutila, J. Khuyagbaatar, J. Krier, M. Leino, J. Louko, M. Luoma, I.D. Moore, P. Mosat, J. Ojala, A. Ortiz-Cortés, J. Pakarinen, P. Papadakis, A.M. Plaza, P. Rahkila, A. Raggio, P. Ruotsalainen, J. Sarén, M. Sandzelius, A. Tolosa-Delgado, J. Uusitalo, G. Zimba

Nuclear Reaction Studies and Prospects for the New MARA-LEB Facility

abstract

A Low Energy Branch for the MARA separator, MARA-LEB, is under construction at the University of Jyväskylä, Finland. It will be used to purify and study exotic beams initially via nuclear decay and laser spectroscopy. Two experiments have been performed using the MARA separator to determine the acceptance of the gas cell and to assess the feasibility of future experiments at the new facility. Products of different reaction mechanisms have been produced and their transmission from the focal plane of MARA into the LEB gas cell has been estimated. In one experiment, medium-mass nuclei have been produced in fusion–evaporation reactions. In a second experiment, with the primary goal of studying the non-fusion reaction dynamics, heavy target-like fragments from multi-nucleon transfer reactions have been produced. Production cross sections have been measured and are presented in this work.


Lifetime Measurements for \(^{46}\)Ti and \(^{50}\)Cr Using the AGATA Spectrometer

abstract

Lifetimes of nuclear-excited states of the cross-conjugate pair of nuclei \(^{46}\)Ti and \(^{50}\)Cr were measured by using the Doppler Shift Attenuation Method (DSAM). High-spin states of these two nuclei were populated by a fusion–evaporation reaction, \(^{16}\)O(\(^{36}\)Ar, \(\alpha n\)). The reduced transition probabilities obtained from the experimental lifetimes are discussed in the framework of theoretical calculations obtained from the shell model using the KB3G and GXPF interaction. Rotational collectivity decreasing by the termination of the yrast band has been confirmed in both nuclei.


all authors

L.G. Pedersen, E. Sahin, A. Görgen, F.L. Bello Garrote, Y. Tsunoda, T. Otsuka, M. Niikura, S. Nishimura, Z. Xu, H. Baba, G. Benzoni, F. Browne, A.M. Bruce, S. Ceruti, F.C.L. Crespi, R. Daido, G. de Angelis, M.-C. Delattre, Zs. Dombradi, P. Doornenbal, Y. Fang, S. Franchoo, G. Gey, A. Gottardo, T. Isobe, P.R. John, H.S. Jung, I. Kojouharov, T. Kubo, N. Kurz, I. Kuti, Z. Li, G. Lorusso, I. Matea, K. Matsui, D. Mengoni, T. Miyazaki, V. Modamio, S. Momiyama, A.I. Morales, P. Morfouace, D.R. Napoli, F. Naqvi, H. Nishibata, A. Odahara, R. Orlandi, Z. Patel, S. Rice, H. Sakurai, H. Schaffner, L. Sinclair, P.-A. Söderström, D. Sohler, I.G. Stefan, T. Sumikama, D. Suzuki, R. Taniuchi, J. Taprogge, Z. Vajta, J.J. Valiente-Dobón, H. Watanabe, V. Werner, J. Wu, A. Yagi, M. Yalcinkaya, R. Yokoyama, K. Yoshinaga

Experimental Level Scheme of \(^{78}\)Cu

abstract

Excited states in \(^{78}\)Cu were observed for the first time following the \(\beta \) decay of \(^{78}\)Ni created by in-flight fission of \(^{238}\)U. Based on the coincidence relationships between the observed \(\gamma \)-ray transitions, it was possible to construct a level scheme comprising eight excited states with tentative spin assignments for 5 of them. In addition to the \(\gamma \)-decaying states, an isomeric state with a lifetime of 3.8(4) ms was found to decay by internal conversion.


all authors

D. Kalaydjieva, P.E. Garrett, H. Bidaman, M. Rocchini, M. Zielińska, W. Korten, V. Bildstein, S. Pannu, Z. Ahmed, C. Andreoiu, D. Annen, G.C. Ball, G. Benzoni, S.S. Bhattacharjee, S. Buck, R.J. Coleman, S. Devinyak, I. Dillmann, R. Caballero-Folch, F.H. Garcia, A.B. Garnsworthy, B. Greaves, C.J. Griffin, G.F. Grinyer, E. Gyabeng Fuakye, G. Hackman, D. Hymers, R. Kanungo, K. Kapoor, E. Kasanda, N. Marchini, K.M. Mashtakov, A. Nannini, C. Natzke, B. Olaizola, K. Ortner, C.M. Petrache, M. Polettini, A.J. Radich, N. Saei, M. Satrazani, M. Siciliano, M. Singh, P. Spagnoletti, C.E. Svensson, D.A. Torres, R. Umashankar, V. Vedia, T. Zidar

First Report of a Doublet 2209-keV State in \(^{100}\)Zr

abstract

A \(\beta \)-decay experiment aiming at investigation of the low-spin structure of \(^{100}\)Zr was performed using the GRIFFIN spectrometer at TRIUMF-ISAC. Based on the obtained data, a new \(2^+\) state is postulated which is degenerate in energy with the established \((5^+)\) level at 2209 keV.


Neutron-deficient Decays in the \(^{48}\)Ni Region with ACTAR TPC

abstract

Since the first indirect measurements of the two-proton radioactivity in 2002, some theoretical descriptions have been able to reproduce experimental results until the 2-proton radioactivity was established for 67Kr at RIKEN, with a lifetime about 20 times lower than predicted. New theory inputs have recently been developed, predicting angular distributions of the emitted protons for some of the two-proton emitters that need to be confirmed experimentally. An experiment at GANIL/LISE3 facility was performed in May 2021 aiming to produce one of the 2-proton emitters (48Ni) and to measure the angular distribution of the emitted protons. We used the ACTAR TPC detector to implant the ions and perform the tracking of their proton decays. In addition, other exotic nuclei in the 48Ni region were produced. For several of them we have found a first evidence of exotic decays such as \(\beta \)-delayed 3- and 2-proton emission or low-energy proton branches for \(\beta \)-delayed single-proton emission.


all authors

M. Kuich, M. Ćwiok, W. Dominik, A. Fijałkowska, M. Fila, A. Giska, Z. Janas, A. Kalinowski, K. Kierzkowski, C. Mazzocchi, W. Okliński, M. Zaremba, D. Grządziel, J. Lekki, W. Królas, A. Kulińska, A. Kurowski, W. Janik, T. Pieprzyca, Z. Szklarz, M. Scholz, M. Turzański, U. Wiącek, U. Woźnicka, A. Caciolli, M. Campostrini, V. Rigato, M. Gai, H.O.U. Fynbo

Active Target TPC for Study of Photonuclear Reactions at Astrophysical Energies

abstract

A setup designed to study photonuclear reactions at astrophysical energies — an active target Time Projection Chamber was developed and constructed at the Faculty of Physics, University of Warsaw. The device was successfully employed in two experiments at the Institute of Nuclear Physics Polish Academy of Sciences in Cracow, in which \(\gamma \)- and neutron-induced reactions with CO\(_2\) gas target were measured. The reaction products were detected and their momenta reconstructed. Preliminary results are shown.


Production Cross Sections of Neutron-deficient Nuclei in \(Z=30\)–36 Region in \(^{78}\)Kr+Be Fragmentation Reaction

abstract

We investigated the production of neutron-deficient nuclei in a fragmentation reaction of \(^{78}\)Kr at 345 MeV/nucleon on a beryllium target in the framework of the abrasion–ablation model. The model parameters were deduced using experimental cross sections in the region. We compiled a dataset of predicted cross-section values for 5–7 most neutron-deficient isotopes of each element from zinc to krypton.


Transfer Reactions with Solenoidal Spectrometers

abstract

The approach of studying direct reactions with solenoidal spectrometers is discussed with reference to transfer reactions, in particular, with a short review of existing solenoidal spectrometers.


The Langevin Approach for Fission of Heavy and Super-heavy Nuclei

abstract

In this contribution, we present the main relations of the Langevin approach to the description of fission or fusion–fission reactions. The results of Langevin calculations are demonstrated for the mass distributions of fission fragments of super-heavy elements and investigation of memory effects in nuclear fission.


Fission Fragments Mass Yields of Actinide Nuclei

abstract

A new, rapidly convergent Fourier over spheroid parametrization is developed to describe the shape of a fissioning nucleus: its elongation, non-axiality and left–right asymmetry, and neck formation. The 4D Potential Energy Surfaces (PES) of even–even actinide nuclei are evaluated within the macro–micro model. The Langevin trajectories generated on such PESs allow for obtaining the fission fragments’ mass and kinetic energy yields. The charge equilibration at the scission configuration and the post-scission neutron emission are also discussed.


Gamow Shell Model Description of \(^7\)Li and Elastic Scattering Reaction \(^4\)He(\(^3\)H,\(^3\)H)\(^4\)He

abstract

The spectrum of \(^7\)Li and the elastic scattering reaction \(^{4}{\mathrm {He}}(^{3}{\mathrm {H}},^{3}\!{\mathrm {H}})^{4}{\mathrm {He}}\) are studied using the unified description of the Gamow shell model in the coupled-channel formulation (GSMCC). The reaction channels are constructed using the cluster expansion with the two mass partitions [\(^4{\mathrm {He}}+^3{\mathrm {H}}\)], [\(^6{\mathrm {Li}}+n\)].


all authors

J. Golak, R. Skibiński, H. Witała, D. Ramirez, V. Urbanevych, V. Chahar

Few-nucleon Systems for Nuclear Physics

abstract

The chiral effective field theory (EFT) and ab initio few- and many-body methods play a very important role in precision nuclear theory. In this contribution, the current status of the chiral nuclear forces derived by the Low Energy Nuclear Physics International Collaboration (LENPIC) is discussed and the role of three-nucleon continuum calculations within LENPIC is described.


Recent Results from the DESPEC Campaign at GSI

abstract

The HISPEC-DESPEC Collaboration proposes to investigate the structure of nuclei produced by projectile fragmentation reactions, focusing on the investigation of heavy exotic nuclei, capitalising on the improved level of sensitivity offered by newly developed detectors coupled to the unique secondary beams available at the GSI-FAIR facility. In the early stages of the experimental activity at FAIR Phase-0, started in 2020, the collaboration focused the attention on the study of the internal structure of exotic systems using \(\gamma \)-ray spectroscopy following the internal decay of metastable nuclear isomeric states, and \(\beta \)-decays with lifetimes in the millisecond-to-second range. A description of the set-up and first results obtained in the experimental campaigns covering the years 2020–2022 are the subject of this paper.


all authors

Yu.A. Litvinov, J. Glorius, M. Steck, T. Stöhlker, K. Blaum, C.G. Bruno, P.J. Woods, I. Dillmann, B. Jurado, W. Korten, X. Ma, Y. Zhang, R. Reifarth, P.M. Walker, T. Yamaguchi

Precision Experiments with Heavy-ion Storage Rings

abstract

This contribution is based on our input to the NuPECC LRP on perspectives of precision experiments at heavy-ion storage rings in the realm of nuclear structure, atomic- and astrophysics. A focus here is on experiments with secondary beams of heavy ions, which can either be stable or long-lived nuclei in specific, high atomic charge states, or unstable nuclides.


all authors

M. Polettini, G. Benzoni, J. Pellumaj, J.J. Valiente-Dobón, G. Zhang, D. Mengoni, R.M. Perez Vidal, Z. Huang, N. Hubbard, H.M. Albers, A. Bracco

\(\beta \)-decay Half-lives Measurements in \(A\sim 225\) Po–Fr Nuclei

abstract

The study presented in this work aims at increasing the experimental knowledge on the hard-to-reach \(220\lt A\lt 230\) \(n\)-rich region. In particular, a systematic study of the \(\beta \)-decay properties of the mentioned nuclei will help to probe the predictions of global nuclear models beyond \(N=126\), an important input to the r-process nucleosynthesis description. Moreover, the \(A\sim 222\) region is the area of the nuclear chart where the strongest octupole deformations are expected to manifest. Preliminary results are reported from an experiment performed at GSI-FAIR (Darmstadt, Germany) in April 2021 within the HISPEC-DESPEC Collaboration experimental campaign, with the aim to study \(220\lt A\lt 230\) Po–Fr nuclei via \(\beta \)-decay measurements.


all authors

Y.K. Tanaka, P. Achenbach, H. Alibrahim Alfaki, F. Amjad, M. Armstrong, K.-H. Behr, J. Benlliure, Z. Brencic, T. Dickel, V. Drozd, S. Dubey, H. Ekawa, S. Escrig, M. Feijoo-Fontán, H. Fujioka, Y. Gao, H. Geissel, F. Goldenbaum, A. Graña González, E. Haettner, M.N. Harakeh, Y. He, H. Heggen, C. Hornung, N. Hubbard, K. Itahashi, M. Iwasaki, N. Kalantar-Nayestanaki, A. Kasagi, M. Kavatsyuk, E. Kazantseva, A. Khreptak, B. Kindler, R. Knoebel, H. Kollmus, D. Kostyleva, S. Kraft-Bermuth, N. Kurz, E. Liu, B. Lommel, V. Metag, S. Minami, D.J. Morrissey, P. Moskal, I. Mukha, A. Muneem, M. Nakagawa, K. Nakazawa, C. Nociforo, H.J. Ong, S. Pietri, J. Pochodzalla, S. Purushothaman, C. Rappold, E. Rocco, J.L. Rodríguez-Sánchez, P. Roy, R. Ruber, T.R. Saito, S. Schadmand, C. Scheidenberger, P. Schwarz, R. Sekiya, V. Serdyuk, M. Skurzok, B. Streicher, K. Suzuki, B. Szczepanczyk, X. Tang, N. Tortorelli, M. Vencelj, H. Wang, T. Weber, H. Weick, M. Will, K. Wimmer, A. Yamamoto, A. Yanai, J. Yoshida, J. Zhao

WASA-FRS Experiments in FAIR Phase-0 at GSI

abstract

We have developed a new and unique experimental setup integrating the central part of the Wide Angle Shower Apparatus (WASA) into the Fragment Separator (FRS) at GSI. This combination opens up possibilities of new experiments with high-resolution spectroscopy at forward \(0^{\circ }\) and measurements of light decay particles with nearly full solid-angle acceptance in coincidence. The first series of the WASA-FRS experiments have been successfully carried out in 2022. The developed experimental setup and two physics experiments performed in 2022 including the status of the preliminary data analysis are introduced.


From ALADiN-LAND to R\(^\mathrm {3}\)B at GSI and FAIR

abstract

This paper is directly based on the talk given at the conference and describes the evolution of our setup and experiments, being initiated and used at GSI, towards a dedicated experiment for various research studies with secondary beams at relativistic velocities for FAIR. Intermediate steps in the commissioning of the novel devices, together with the addressed physics questions, in the frame of Phase-0 beam times, are presented. Dedicated prototype studies at the SAMURAI setup in RIKEN are also presented. The general time-line for the Super-FRS facility at FAIR with intense SIS‑18 and SIS-100 beams is discussed and prospects for associated physics studies are shown.


Nuclear Fission Studies in Inverse Kinematics with the R\(^3\)B Setup at the GSI-FAIR Facility

abstract

Despite the recent experimental and theoretical progress in the investigation of the nuclear fission process, a complete description still represents a challenge in nuclear physics because it involves the coupling between intrinsic and collective degrees of freedom as well as different quantum-mechanical phenomena. In the last decade, unprecedented fission experiments have been carried out within the Reactions with Relativistic Radioactive Beams (R\(^3\)B) Collaboration at the GSI facility by using the inverse kinematics technique in combination with state-of-the-art detectors especially designed to measure the fission products with high detection efficiency and acceptance.


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A. Yaneva, S. Jazrawi, B. Das, M. Mikolajczuk, M. Górska, P.H. Regan, B. Cederwall, J. Jolie, G. Benzoni, H.M. Albers, S. Alhomaidhi, T. Arici, A. Banerjee, M.M.R. Chishti, T. Davinson, J. Gerl, O. Hall, N. Hubbard, I. Kojouharov, A.K. Mistry, M. Polettini, M. Rudigier, E. Sahin, H. Schaffner, A. Sharma, H.J. Wollersheim, P. Boutachkov, T. Dickel, E. Haettner, H. Heggen, Ch. Hornung, R. Knöbel, D. Kostyleva, N. Kurz, N. Kuzminchuk, I. Mukha, S. Pietri, W.R. Plass, Zs. Podolyak, C. Scheidenberger, Y.K. Tanaka, J. Vesic, H. Weick, U. Ahmed, Ö. Aktas, A. Algora, C. Appleton, J. Benito, A. Blazhev, A. Bracco, A. Bruce, M. Brunet, R. Canavan, A. Esmaylzadeh, L.M. Fraile, G. Häfner, K.P. Hucka, P.R. John, D. Kahl, V. Karayonchev, R. Kern, G. Kosir, R. Lozeva, P. Napiralla, B.S. Nara Singh, R.D. Page, C.M. Petrache, N. Pietralla, J.-M. Regis, H. Rösch, P. Ruotsalainen, V. Sanchez-Temble, L. Sexton, R. Shearman, M. Si, V. Werner, J. Wiederhold, K. Wimmer, W. Witt, P. Woods, G. Zimba

Fast-timing Measurement in \(^{96}\)Pd: Improved Accuracy for the Lifetime of the \(4_1^{+}\) State

abstract

Direct lifetime measurements via \(\gamma \)–\(\gamma \) coincidences using the FATIMA fast-timing LaBr\(_{3}\)(Ce) array were performed for the excited states below previously reported isomers. In the \(N=50\) semi-magic \(^{96}\)Pd nucleus, lifetimes below the \(I^{\pi }=8^{+}\) seniority isomer were addressed as a benchmark for further analysis. The results for the \(I^{\pi }=2^{+}\) and \(4^{+}\) states confirm the published values. Increased accuracy for the lifetime value was achieved for the \(4^{+}\) state.


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V. Guadilla, A. Algora, M. Fallot, J.L. Tain, J. Agramunt, J. Äystö, J.A. Briz, A. Cucoanes, T. Eronen, M. Estienne, L.M. Fraile, E. Ganioğlu, W. Gelletly, D. Gorelov, J. Hakala, A. Jokinen, D. Jordan, A. Kankainen, V. Kolhinen, J. Koponen, M. Lebois, L. Le Meur, T. Martinez, M. Monserrate, A. Montaner-Pizá, I. Moore, E. Nácher, S.E.A. Orrigo, H. Penttilä, I. Pohjalainen, A. Porta, J. Reinikainen, M. Reponen, S. Rinta-Antila, B. Rubio, K. Rytkönen, T. Shiba, V. Sonnenschein, A.A. Sonzogni, E. Valencia, V. Vedia, A. Voss, J.N. Wilson, A.-A. Zakari-Issoufou

Results of DTAS Campaign at IGISOL: Overview

abstract

The \(\beta \) decays of more than twenty fission fragments were measured in the first experiments with radioactive-ion beams employing the Decay Total Absorption \(\gamma \)-ray Spectrometer. In this work, we summarize the main results obtained so far from this experimental campaign carried out at the Ion Guide Isotope Separator On-Line facility. The advances introduced for these studies represent the state-of-the-art of our analysis methodology for segmented spectrometers.


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D. Nurkić, M. Milin, D. Jelavić Malenica, N. Vukman, N. Vidović, N. Soić, P. Figuera, A. Di Pietro, S. Cherubini, P. Čolović, S. Heinitz, L. Lamia, E.A. Maugeri, R.G. Pizzone, S. Romano, D. Schumann, C. Spitaleri, A. Tumino, M. Uroić

Cluster States in Carbon Isotopes \(^{13-15}\)C Studied with the \(^{10}\mathrm {Be}+{^{9}}\mathrm {Be}\) Reactions

abstract

In this contribution, a set of results will be given of an experiment performed at LNS-INFN with a 54 MeV \(^{10}\)Be beam and a \(^9\)Be target. The experimental setup consists of four highly segmented telescopes covering polar angles from \(20^{\circ }\) to \(90^{\circ }\) which enable particle identification using traditional \({\Delta }E\)–\(E\) techniques. The \(^{10}\mathrm {Be}+{^{9}}\)Be reactions are measured to get information on different types of structures of several light nuclei. Special attention is given to a search for cluster states in \(^{14}\)C and \(^{15}\)C. The experimental signature of these processes would be the first indication of the existence of cluster states inside the \(^{15}\)C nucleus, while a positive result for the \(^{14}\)C isotope would help to clear up the contradicting findings of other authors. The results for \(^{14}\)C and \(^{15}\)C are not yet fully interpreted, so here we show the \(^{13}\)C excitation energies coming from the \(^{6}\)He single detections and \(^{6}\mathrm {He}+{^{4}}\)He coincidences.


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G. Corbari, S. Bottoni, M. Ciemala, F.C.L. Crespi, S. Leoni, B. Fornal, R.V.F. Janssens, S.D. Pain, M. Siciliano, E. Albanese, A.D. Ayangeakaa, G. Benzoni, S. Carmichael, M. Carpenter, K. Chipps, N. Cieplicka, P. Copp, J. Forson, E. Gamba, L.W. Iskra, H. Jayatissa, F. Kondev, T. Lauritsen, B. Million, C. Müller-Gatermann, A. Palmisano, M. Polettini, C. Porzio, W. Reviol, N. Sensharma, D. Seweryniak, C. Ummel, O. Wieland, G. Wilson, S. Zhu, S. Ziliani

\(\gamma \) Decay from the Near-neutron-threshold \(2^{+}\) State in \(^{14}\)C: A Probe of Collectivization Phenomena in Light Nuclei

abstract

A search for the \(\gamma \) decay of the \(2^+_2\) near-threshold resonance in \(^{14}\)C, located 142 keV above the neutron separation energy, was performed at the Argonne National Laboratory with the GRETINA \(\gamma \)-ray spectrometer coupled to the ORRUBA Si detectors. The sensitivity of the experiment was of the order of 2.6\(\times \)10\(^{-5}\). This is comparable to the gamma branch calculated by the Shell Model Embedded in the Continuum, which predicts a significant enhancement of the \(2^+_2\rightarrow 0\) transition probability, as a consequence of the collectivization of the near-threshold state.


all authors

N. Vukman, N. Soić, M. Freer, M. Alcorta, D. Connolly, P. Čolović, T. Davinson, A. Di Pietro, A. Lennarz, A. Psaltis, C. Ruiz, A. Shotter, M. Uroić, M. Williams

Helium Clustering in Neutron-rich Be Isotopes

abstract

The experimental study of the helium decays of the \(^{10}\)Be and \(^{12}\)Be excited states was performed at TRIUMF, Vancouver, using the transfer reactions of the \(^9\)Li beam on the LiF target and resonant particle spectroscopy technique. Part of the results from the full dataset are presented here, for the \(^4\)He+\(^6\)He (0\(^+\); 1.8 MeV, 2\(^+\)), \(^6\)He+\(^6\)He (0\(^+\); 1.8 MeV, 2\(^+\)), and \(^4\)He+\(^8\)He decays of the \(^{10}\)Be and \(^{12}\)Be excited states, respectively. The \(^6\)He+\(^6\)He (1.8 MeV, 2\(^+\)) decay channel was observed for the first time in the present experiment, while for the \(^4\)He+\(^6\)He (1.8 MeV, 2\(^+\)) decay channel, there was previously only one measurement available, which present results agree with. New highly excited states were observed in all decay channels studied. Although branching ratios and the spins of the states were not determined, important spectroscopic information is obtained and present results are in good agreement with the proposed \(\alpha \)–\(Xn\)–\(\alpha \) molecular structure of these isotopes, based on the comparison with previously published results.


all authors

L. Al Ayoubi, I. Matea, A. Kankainen, D. Verney, H. Al Falou, G. Benzoni, V. Bozkurt, M. Ciemala, C. Delafosse, I. Deloncle, F. DidierJean, M. Fallot, C. Gaular, A. Gottardo, V. Guadilla, J. Guillot, K. Hadyńska-Klęk, F. Ibrahim, N. Jovancevic, F. Le Blanc, M. Lebois, R. Li, T. Martínez, P. Napiorkowski, B. Roussiere, Yu.G. Sobolev, B. Sowicki, I. Stefan, S. Stukalov, D. Thisse, G. Tocabens

Beta Decay of \(^{82}\)Ga Studied at the ALTO Facility

abstract

Excited states in the \(N=50\) nucleus \(^{82}\)Ge have been investigated via beta decay of \(^{82}\)Ga at the ALTO facility. More than 50 new gamma transitions were identified. The preliminary results are presented in this work.


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G. Jaworski, M. Palacz, A. Goasduff, M. Kowalczyk, P. Kulessa, I. Kuti, M. Matuszewski, B. Radomyski, N. Toniolo, T. Abraham, G. Colucci, A. Fijałkowska, K. Hadyńska-Klęk, M. Komorowska, R. Kopik, L. Lappo, A. Malinowski, P.J. Napiorkowski, W. Okliński, A. Otręba, S. Panasenko, W. Poklepa, J. Samorajczyk-Pyśk, K. Wrzosek-Lipska, K. Zdunek

NEEDLE — the New Setup to Study Neutron-deficient Nuclei

abstract

A state-of-the-art neutron multiplicity filter NEDA has been installed as an ancillary detector to the EAGLE gamma-ray spectrometer at the Heavy Ion Laboratory, University of Warsaw. This significantly broadens the areas of the nuclear chart accessible by employing the Warsaw apparatus. The properties of the new setup are discussed.


Supervised Event Classification in an Optical Time Projection Chamber

abstract

Machine Learning algorithms trained on Monte Carlo simulated data are proposed for the classification of experimental data from an Optical Time Projection Chamber. In this contribution, we describe the simulation procedure to mimic experimental data, as well as the algorithms chosen for nuclear physics cases of \(\beta \)-delayed (multi)-particle emission and two-proton radioactivity. A proof of principle of the whole procedure is discussed for the decay of \(^{11}\)Be.


Manifestation of Pairing Modes in Nuclear Collisions

abstract

We discuss the possible manifestation of pairing dynamics in nuclear collisions beyond the standard quasi-static treatment of pairing correlations. These involve solitonic excitations induced by pairing phase difference of colliding nuclei and pairing dynamic enhancement in the di-nuclear system formed by merging nuclei.


Yield Analysis of Residues from \(^{12}\)C+\(^{93}\)Nb Reaction: Production of Medically Important \(^{101m}\)Rh via \(^{101}\)Pd

abstract

Production of \(^{101m}\)Rh radionuclide, which is a preferred candidate for diagnostic imaging and radiotherapy, has been reported from a heavy-ion reaction \(^{12}\)C+\(^{93}\)Nb. In addition to its formation as an evaporation residue of \(^{105}\)Ag\(^*\) compound nucleus, it was formed significantly through electron capture decay of its precursor \(^{101}\)Pd within the 39.5–75.9 MeV range. Followed by activation, \(\gamma \)-ray spectroscopy was employed to identify evaporation residues. A maximum yield of 793.4 and 89.4 MBq/C at 71.0 MeV was measured for \(^{101}\)Pd and \(^{101m}\)Rh, respectively, along with other co-produced radionuclides. The conditions for optimizing the yield of \(^{101m}\)Rh to ensure its purity have been discussed. Subsequently, the thick target yield for \(^{101m}\)Rh is estimated using the model code EMPIRE-3.2.2.


Investigation of Rare Nuclear Decays — Double gamma Decay in \(^{137}\)Ba Nucleus

abstract

Double gamma decay is a rare nuclear decay process first studied in 1930 by Maria Göppert-Mayer in her doctoral thesis. In this decay process, an excited nuclear state decays to a lower-lying state via a virtual intermediate state and emits two photons simultaneously. The sum of the energies of these two photons corresponds to the energy difference between the initial and final states. So far, this type of decay has been mainly observed in nuclei for which single-photon decay is forbidden (\(0^+_2\to 0^+\) transitions). The only case in which double gamma decay competes with a single gamma decay has been measured is \(^{137}\)Ba. This paper contains information on the experimental setup developed at the Institute of Nuclear Physics Polish Academy of Sciences, Kraków (IFJ PAN) for the measurements of the double gamma decay. We present preliminary results for the study of the \(^{137}\)Ba \(11/2^-\) excited level double gamma decay, which was chosen as the reference case, before starting the systematic study of this rare process.


Exploring Entrance Channel Effects in the Interaction of \(^{16}\)O with \(^{93}\)Nb

abstract

The excitation functions (EFs) of the number of evaporation residues have been measured in the interaction of a \(^{16}\)O projectile with a \(^{93}\)Nb target at energies \(\approx 3.5\)–7 MeV/\(A\) using a well established activation technique followed by off-line \(\gamma \)-ray spectroscopy. The measured excitation functions have been compared with theoretical predictions obtained using the statistical model code PACE4. The EFs of evaporation residues populated through \(\alpha \)-emitting channels show an enhancement over theoretical predictions calculated using the fusion-based model code. Incomplete fusion dynamics is found to play an important role in heavy-ion-induced reactions at energies as low as 3.5–7 MeV/\(A\). To have more exclusive information about ICF dynamics, the strength of ICF in terms of the incomplete-fusion fraction (\(F_{\mathrm {ICF}}\)) is also deduced and correlated with various entrance channel parameters. It is found that besides projectile energy, projectile structure and mass asymmetry strongly affect the ICF dynamics in the considered energy range.


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