Bronis, A.*; Heberger, F. P.*; Antalic, S.*; Andel, B.*; Ackermann, D.*; Heinz, S.*; Hofmann, S.*; Khuyagbaatar, J.*; Kindler, B.*; Kojouharov, I.*; et al.
Physical Review C, 106(1), p.014602_1 - 014602_12, 2022/07
The decay of excited states in No was investigated by applying the evaporation-residue-conversion-electron correlation technique. Two new isomeric states were observed in No together with the previously known one. Excitation energies of the isomeric states were estimated based on the energies of conversion electrons and rays from correlation chains. These results were in accord with theoretical calculations based on the mean-field models. A tentative decay scheme of isomeric states in No is proposed, and their Nilsson configurations are discussed. The energy decrease of the 11/2 Nilsson level for heavy =153 isotones as a function of increasing proton number is confirmed.
Heussner, F.*; Talmelli, G.*; Geilen, M.*; Heinz, B.*; Brcher, T.*; Meyer, T.*; Ciubotaru, F.*; Adelmann, C.*; 山本 慧; Serga, A. A.*; et al.
Physica Status Solidi; Rapid Research Letters, 14(4), p.1900695_1 - 1900695_6, 2020/04
The emerging field of magnonics employs spin waves and their quanta, magnons, to implement wave-based computing on the micro- and nanoscales. Multi-frequency magnon networks would allow for parallel data processing within single logic elements whereas this is not the case with conventional transistor-based electric logic. However, a lack of experimental proven solutions to efficiently combine and separate magnons of different frequencies has impeded the intensive use of this concept. In this Letter, the experimental realization of a spin-wave demultiplexer enabling frequency-dependent separation of magnetic signals in the GHz range is demonstrated. The device is based on two-dimensional magnon transport in the form of spin-wave beams in unpatterned magnetic films. The intrinsic frequency-dependence of the beam direction is exploited to realize a passive functioning obviating an external control and additional power consumption. This approach paves the way to magnonic multiplexing circuits enabling simultaneous information transport and processing.
Devaraja, H. M.*; Heinz, S.*; Beliuskina, O.*; Hofmann, S.*; Hornung, C.*; Mnzenberg, G.*; Ackermann, D.*; Gupta, M.*; Gambhir, Y. K.*; Henderson, R. A.*; et al.
European Physical Journal A, 55(2), p.25_1 - 25_9, 2019/02
The results for nuclei above curium, produced in multi-nucleon transfer reactions of Ca+Cm at the velocity filter SHIP of GSI Darmstadt, are presented. Spontaneous fission and activities have been used to study the population of nuclei with lifetimes ranging from few milliseconds to several days. We observed several, relatively neutron-rich isotopes with atomic numbers Z 98; among them a weak 224 millisecond activity which we tentatively attributed to No. The measured cross-sections of the observed nuclei give hope that multi-nucleon transfer reactions are a way to reach new neutron-rich heavy and superheavy nuclei, which are not accessible in other reactions. We compare our results with data from earlier experiments and discuss limitations and future perspectives of the method.
Lopez-Martens, A.*; Henning, G.*; Khoo, T. L.*; Seweryniak, D.*; Alcorta, M.*; 浅井 雅人; Back, B. B.*; Bertone, P. F.*; Boilley, D.*; Carpenter, M. P.*; et al.
EPJ Web of Conferences, 131, p.03001_1 - 03001_6, 2016/12
Hofmann, S.*; Heinz, S.*; Mann, R.*; Maurer, J.*; Mnzenberg, G.*; Antalic, S.*; Barth, W.*; Burkhard, K. G.*; Dahl, L.*; Eberhardt, K.*; et al.
European Physical Journal A, 52(6), p.180_1 - 180_34, 2016/06
The reaction Cr+Cm was investigated at the velocity filter SHIP at GSI with the intention to study production and decay properties of isotopes of element 120. Three correlated signals were measured, which occurred within a period of 279 ms. The heights of the signals correspond with the expectations for a decay sequence starting with an isotope of element 120. However, a complete decay chain cannot be established, since a signal from the implantation of the evaporation residue cannot be identified unambiguously. Measured properties of the event chain are discussed in detail. The result is compared with theoretical predictions. Previously measured decay properties of even element super-heavy nuclei were compiled in order to find arguments for an assignment from the systematics of experimental data. In the course of this review, a few tentatively assigned data could be corrected. New interpretations are given for results which could not be assigned definitely in previous studies. The discussion revealed that the cross-section for production of element 120 could be high enough so that a successful experiment seems possible with presently available techniques. However, a continuation of the experiment at SHIP for a necessary confirmation of the results obtained in a relatively short irradiation of five weeks is not possible at GSI presently. In the summary and outlook section we also present concepts for the continuation of research in the field of super-heavy nuclei.
Hofmann, S.*; Heinz, S.*; Mann, R.*; Maurer, J.*; Mnzenberg, G.*; Antalic, S.*; Barth, W.*; Dahl, L.*; Eberhardt, K.*; Grzywacz, R.*; et al.
European Physical Journal A, 52(4), p.116_1 - 116_12, 2016/04
Shell-correction energies of super-heavy nuclei are approximated by using Q values of measured decay chains. Five decay chains were analyzed, which start at the isotopes Fl, 118, Lv, Lv and Lv. The data are compared with predictions of macroscopic-microscopic models. Fission barriers are estimated that can be used to eliminate uncertainties in partial fission half-lives and in calculations of evaporation-residue cross-sections. In that calculations, fission probability of the compound nucleus is a major factor contributing to the total cross-section. The data also provide constraints on the cross-sections of capture and quasi-fission in the entrance channel of the fusion reaction. Arguments are presented that fusion reactions for synthesis of isotopes of elements 118 and 120 may have higher cross-sections than assumed so far.
Devaraja, H. M.*; Heinz, S.*; Beliuskina, O.*; Comas, V. F.*; Hofmann, S.*; Hornung, C.*; Mnzenberg, G.*; 西尾 勝久; Ackermann, D.*; Gambhir, Y. K.*; et al.
Physics Letters B, 748, p.199 - 203, 2015/09
In deep inelastic multinucleon transfer reactions of Ca +Cm we observed about 100 residual nuclei with proton numbers between Z =82 and Z =100. Among them, there are five new neutron-deficient isotopes: U, Np, Am, Am and Bk. As separator for the transfer products we used the velocity filter SHIP of GSI while the isotope identification was performed via the -decay chains of the nuclei. These first results reveal that multinucleon transfer reactions together with here applied fast and sensitive separation and detection techniques are promising for the synthesis of new isotopes in the region of heaviest nuclei.
Sambi, S.*; Raabe, R.*; Borge, M. J. G.*; Caamano, M.*; Damoy, S.*; Fernndez-Domnguez, B.*; Flavigny, F.*; Fynbo, H.*; Gibelin, J.*; Grinyer, G. F.*; et al.
European Physical Journal A, 51(3), p.25_1 - 25_7, 2015/03
In a proof-of-principle experiment, the Maya active target detector was employed to study the C(p,p) resonant elastic scattering reaction in inverse kinematics. The excitation energy region from 0 to 3 MeV above the proton-breakup threshold in N was investigated in a single experiment. The excitation spectrum of N was fitted using R-matrix formalism. The level parameters extracted are in good agreement with previous studies. The active target proved its potential for the study of resonant elastic scattering in inverse kinematics with radioactive beams, when detection efficiency is of primary importance.
Henning, G.*; Khoo, T. L.*; Lopez-Martens, A.*; Seweryniak, D.*; Alcorta, M.*; 浅井 雅人; Back, B. B.*; Bertone, P. F.*; Boilley, D.*; Carpenter, M. P.*; et al.
Physical Review Letters, 113(26), p.262505_1 - 262505_6, 2014/12
Henning, G.*; Lopez-Martens, A.*; Khoo, T. L.*; Seweryniak, D.*; Alcorta, M.*; 浅井 雅人; Back, B. B.*; Bertone, P. F.*; Boilley, D.*; Carpenter, M. P.*; et al.
EPJ Web of Conferences, 66, p.02046_1 - 02046_8, 2014/03
Andreyev, A. N.*; Liberati, V.*; Antalic, S.*; Ackermann, D.*; Barzakh, A.*; Bree, N.*; Cocolios, T. E.*; Diriken, J.*; Elseviers, J.*; Fedorov, D.*; et al.
Physical Review C, 87(5), p.054311_1 - 054311_8, 2013/05
-decay studies of Tl and its dahghter products Au and Ir were carried out in two complementary experiments at the mass separator ISOLDE (CERN) and velocity filter SHIP (GSI). The nucluesu Au has decay properties of half-life 207 ms and -decay energy 6433 keV. The ground state spins and parities for Au and Ir were determined to be 1/2.
西尾 勝久; 池添 博; Hofmann, S.*; Ackermann, D.*; 有友 嘉浩*; Comas, V. F.*; Dllmann, Ch. E.*; Heinz, S.*; Heredia, J. A.*; Heberger, F. P.*; et al.
AIP Conference Proceedings 1524, p.68 - 72, 2013/04
Fission fragment mass and kinetic energies distributions were measured in the heavy-ion induced reactions using U target nucleus at the energies around the Coulomb barrier. We observed strong variation of the fragment mass distribution with incident energy, which was explained by an energy dependence of the probabilities for fusion and quasifission. A calculation based on a fluctuation-dissipation model was carried out to determine the fusion probability in the reactions of Si+U and S+U. The fusion probabilities were consistent with those determied from the evaporation residue cross sections for both reactions, showing that in-beam fission measurement and analysis can give a reasonable estimation for the cross sections to produce super-heavy nuclei. We also discss the results for in-beam fission measurement of Ca+U.
Andreyev, A. N.*; Antalic, S.*; Ackermann, D.*; Bianco, L.*; Franchoo, S.*; Heinz, S.*; Heberger, F. P.*; Hofmann, S.*; Huyse, M.*; Kalaninov, Z.*; et al.
Physical Review C, 87(1), p.014317_1 - 014317_8, 2013/01
By using the recoil-fission correlation technique, the exotic process of beta-delayed fission (DF) was unambiguously identified in the very neutron-deficient nuclei At in experiments at the velocity filter SHIP at Gesellschaft fr Schwerionenforschung (GSI). The upper limits for the total kinetic energy release in fission of Po, being the daughter of At after decay, were estimated. The possibility of an unusually high DF probability At is discussed.
Hofmann, S.*; Heinz, S.*; Mann, R.*; Maurer, J.*; Khuyagbaatar, J.*; Ackermann, D.*; Antalic, S.*; Barth, B.*; Block, M.*; Burkhard, H. G.*; et al.
European Physical Journal A, 48(5), p.62_1 - 62_23, 2012/05
The synthesis of element 116 in the reactions of Ca+Cm was studied at the GSI-SHIP. Four decay chains from the isotope 116 and one decay 116 were detected at the reaction leading to the excitation energy of 40.9 MeV. The cross sections were 3.4 and 0.9 pb, respectively. The decay character reproduced the reported data at FLNR, Russia. In the decay chain, we observed the higher -particle energy in the decay of 114, which suggested the population and the decay of a quasiparitcle state.
西尾 勝久; 池添 博; Hofmann, S.*; Ackermann, D.*; Antalic, S.*; 有友 嘉浩; Comas, V. F.*; Dllmann, Ch. E.*; Gorshkov, A.*; Graeger, R.*; et al.
EPJ Web of Conferences, 17, p.09005_1 - 09005_4, 2011/10
Fission fragment mass distributions after full momentum transfer of the projectile were measured in the reactions using a U target nucleus bombarded by Si, P, S, Ar, Ca projectiles. We observed a strong variation of the distribution as function of bombarding energy. The results were interpreted by the effects of nuclear deformation of the target nucleus on the competition between fusion and quasifission. The symmetric fission includes fusion-fission, wheres as the asymmetric fission represents quasifission. The fusion probabilities were determined with the help of fluctuation-dissipation model. The estimated evaporation residue cross sections (Sg and Hs) produced in Si + U and S+U reproduced the experimental data.
Steer, S. J.*; Podolyk, Z.*; Pietri, S.*; Grska, M.*; Grawe, H.*; Maier, K.*; Regan, P. H.*; Rudolph, D.*; Garnsworthy, A. B.*; Hoischen, R.*; et al.
Physical Review C, 84(4), p.044313_1 - 044313_22, 2011/10
Robinson, A. P.*; Khoo, T. L.*; Seweryniak, D.*; Ahmad, I.*; 浅井 雅人; Back, B. B.*; Carpenter, M. P.*; Chowdhury, P.*; Davids, C. N.*; Greene, J.*; et al.
Physical Review C, 83(6), p.064311_1 - 064311_7, 2011/06
Khuyagbaatar, J.*; Heberger, F. P.*; Hofmann, S.*; Ackermann, D.*; Comas, V. F.*; Heinz, S.*; Heredia, J. A.*; Kindler, B.*; Kojouharov, I.*; Lommel, B.*; et al.
European Physical Journal A, 46(1), p.59 - 67, 2010/10
The isotope Cf were produced in irradiation of Pb targets with S ions at bombarding energies close to the Coulomb barrier. For the isotope Cf a spontaneous fission branching of 0.015 was determined. The new isotope Cm was produced by decay of Cf. It decays with 6954-keV particle emission, and half-life was determined to be 410 s. The -decay of Cf was observed for the first time, and the particle energy was 8081 keV. For the isotope Cm a half-life 23 s was measured for the first time.
西尾 勝久; Hofmann, S.*; Heberger, F. P.*; Ackermann, D.*; Antalic, S.*; 有友 嘉浩; Comas, V. F.*; Dllmann, Ch. E.*; Gorshkov, A.*; Graeger, R.*; et al.
Physical Review C, 82(2), p.024611_1 - 024611_9, 2010/08
Synthesis of isotopes of the element hassium was studied using the reaction S+UHs*. At a kinetic energy of 163.0 MeV in the center of mass system we observed one -decay chain starting at the isotope Hs. The cross-section was 1.8pb. At 152.0 MeV one decay of the new isotope Hs was observed. It decays with a half-life of 0.38s by 947916 keV -particle emission. Spontaneous fission of the daughter nucleus Sg was confirmed. The measured cross-section was 0.54pb. In-beam measurements of fission fragment mass distributions were performed to obtain information on the fusion probability at various orientation of the deformed target nucleus. The distributions changed from symmetry to asymmetry when the beam energy was changed from above-barrier to sub-barrier values, indicating orientation effects on fusion and/or quasifission. It was found that the distribution of symmetric mass fragments originates not only from fusion-fission, but has a strong component from quasifission. This result significantly influences the interpretation of data obtained from measurements of symmetric mass distributions with respect to extracting evaporation residue cross-sections.
Seweryniak, D.*; Khoo, T. L.*; Ahmad, I.*; Kondev, F. G.*; Robinson, A.*; Tandel, S. K.*; 浅井 雅人; Back, B. B.*; Carpenter, M. P.*; Chowdhury, P.*; et al.
Nuclear Physics A, 834(1-4), p.357c - 361c, 2010/03