1. |
- Albers, M., et al.
(author)
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Single-particle and collective excitations in Ni-63
- 2013
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In: Physical Review C (Nuclear Physics). - 0556-2813. ; 88:5
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Journal article (peer-reviewed)abstract
- A study of excited states in Ni-63 up to an excitation energy of 28 MeV and a probable spin of 57/2 was carried out with the Mg-26(Ca-48,2 alpha 3n gamma)Ni-63 reaction at beam energies between 275 and 320 MeV. Three collective bands, built upon states of single-particle character, were identified. For two of the three bands, the transition quadrupole moments were extracted, herewith quantifying the deformation at high spin. The results have been compared with shell-model and cranked Nilsson-Strutinsky calculations. Despite the Z = 28 shell closure and the approach to the purported N = 40 subshell, the Ni-63 isotope is able to sustain collective excitations at moderate and high spin.
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2. |
- Alexander, T., et al.
(author)
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Isomeric Ratios in 206Hg
- 2015
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In: Acta Physica Polonica. Series B: Elementary Particle Physics, Nuclear Physics, Statistical Physics, Theory of Relativity, Field Theory. - 0587-4254. ; 46:3, s. 601-605
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Journal article (peer-reviewed)abstract
- Hg-206 was populated in the fragmentation of an E/A = 1 GeV Pb-208 beam at GSI. It was part of a campaign to study nuclei around Pb-208 via relativistic Coulomb excitation. The observation of the known isomeric states confirmed the identification of the fragmentation products. The isomeric decays were also used to prove that the correlations between beam identification detectors and the AGATA gamma-ray tracking array worked properly and that the tracking efficiency was independent of the time relative to the prompt flash.
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3. |
- Devi, Chandni, et al.
(author)
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High sodium ionic conductivity in PEO/PVP solid polymer electrolytes with InAs nanowire fillers
- 2021
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In: Scientific Reports. - London : Nature Publishing Group. - 2045-2322. ; 11:1
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Journal article (peer-reviewed)abstract
- Solid-state sodium ion batteries are frequently referred to as the most promising technology for next-generation energy storage applications. However, developing a suitable solid electrolyte with high ionic conductivity, excellent electrolyte–electrode interfaces, and a wide electrochemical stability window, remains a major challenge. Although solid-polymer electrolytes have attracted great interest due to their low cost, low density and very good processability, they generally have significantly lower ionic conductivity and poor mechanical strength. Here, we report on the development of a low-cost composite solid polymer electrolyte comprised of poly(ethylene oxide), poly(vinylpyrrolidone) and sodium hexafluorophosphate, mixed with indium arsenide nanowires. We show that the addition of 1.0% by weight of indium arsenide nanowires increases the sodium ion conductivity in the polymer to 1.50 × 10−4 Scm−1 at 40 °C. In order to explain this remarkable characteristic, we propose a new transport model in which sodium ions hop between close-spaced defect sites present on the surface of the nanowires, forming an effective complex conductive percolation network. Our work represents a significant advance in the development of novel solid polymer electrolytes with embedded engineered ultrafast 1D percolation networks for near-future generations of low-cost, high-performance batteries with excellent energy storage capabilities. © 2021, The Author(s).
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4. |
- Gates, J. M., et al.
(author)
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First Superheavy Element Experiments at the GSI Recoil Separator TASCA: The Production and Decay of Element 114 in the 244Pu(48Ca,3-4n) Reaction
- 2011
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In: Physical Review C (Nuclear Physics). - 0556-2813. ; 83:5
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Journal article (peer-reviewed)abstract
- Experiments with the new recoil separator, Transactinide Separator and Chemistry Apparatus (TASCA), at the GSI were performed by using beams of Ca-48 to irradiate targets of Pb206-208, which led to the production of No252-254 isotopes. These studies allowed for evaluation of the performance of TASCA when coupled to a new detector and electronics system. By following these studies, the isotopes of element 114 ((288-291)114) were produced in irradiations of Pu-244 targets with Ca-48 beams at compound nucleus excitation energies around 41.7 and 37.5 MeV, demonstrating TASCA's ability to perform experiments with picobarn-level cross sections. A total of 15 decay chains were observed and were assigned to the decay of 288-291114. A new a-decay branch in (281)Ds was observed, leading to the new nucleus (277)Hs.
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5. |
- Gellanki, Jnaneswari, et al.
(author)
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Characterization of Superdeformed Bands in 62Zn
- 2009
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In: Physical Review C (Nuclear Physics). - 0556-2813. ; 80:5
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Journal article (peer-reviewed)abstract
- Combined data from four fusion-evaporation reaction experiments were utilized to investigate deformed and superdeformed structures in Zn-62(30)32. Combination of the Gammasphere gamma-ray spectrometer and ancillary particle detection systems allowed for the connection of rotational bands to well-known, low-lying excited states in Zn-62, as well as spectroscopy of discrete high-spin states reaching excitation energies of E-x=42.5 MeV. Four well- or superdeformed bands in Zn-62 are characterized and described by means of cranked Nilsson-Strutinsky calculations.
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6. |
- Gellanki, Jnaneswari, et al.
(author)
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Comparative Study of Rotational Bands in the A~60 Mass Region: Modification of Nilsson Parameters
- 2014
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In: Physical Review C (Nuclear Physics). - 0556-2813. ; 89:2
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Journal article (peer-reviewed)abstract
- The large number of high-spin bands that have been observed in A=56-62 nuclei are analyzed systematically within the cranked Nilsson-Strutinsky approach. Optimized Nilsson single-particle parameters are derived from investigations of energy differences between experimental and calculated rotational bands. Specifically, the relative energies of bands in neighboring nuclei whose configurations differ by having a high-j orbital either filled or empty are analyzed. The level schemes calculated with the new Nilsson parameters are compared with those using standard Nilsson parameters. Some configuration assignments are revised.
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7. |
- Gellanki, Jnaneswari
(author)
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Comprehensive Gamma-Ray Spectroscopy of 62Zn and Studies of Nilsson Parameters in the Mass A = 60 Region
- 2013
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Doctoral thesis (other academic/artistic)abstract
- Comprehensive experimental knowledge of the 62Zn nucleus has been obtained from the combined statistics of four different experiments. The Gammasphere Ge-detector array in conjunction with the 4pi charged-particle detector array Microball was used to detect the gamma-rays in coincidence with evaporated light charged particles. In total twenty seven band structures have been observed in 62Zn, twenty for the first time. The resulting extensive decay scheme comprises almost 260 excited states, which are connected with more than 450 gamma-ray transitions. The multipolarities have been determined for the gamma-ray transitions and as a result spin-parity assignments are given for nearly all energy levels. The collective structures are compared with results from configuration dependent Cranked Nilsson-Strutinsky calculations. The effective alignment method has been applied to check out the spin, parity and theoretical configuration assignments of the existing experimental bands and thereby identify the behaviour of the band structures in the A ~ 60 mass region.
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8. |
- Gellanki, Jnaneswari, et al.
(author)
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Extensive Gamma-ray Spectroscopy of Band Structures in 62Zn
- 2012
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In: Physical Review C (Nuclear Physics). - 0556-2813. ; 86:3
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Journal article (peer-reviewed)abstract
- An experimental study of the Zn-62 nucleus has been performed by combining the data sets from four fusion-evaporation reaction experiments. Apart from the previously published data, the present results include ten new rotational band structures and two more superdeformed bands. The Gammasphere Ge-detector array in conjunction with the 4 pi charged-particle detector array Microball allowed for the detection of gamma rays in coincidence with evaporated light particles. The deduced level scheme includes some 260 excited states, which are connected with more than 450 gamma-ray transitions. Spins and parities of the excited states have been determined via directional correlations of. rays emitted from oriented states. The experimental characteristics of the rotational bands are analyzed and compared with results from cranked Nilsson-Strutinsky calculations. The present analysis, combined with available experimental results in the A similar to 60 mass region, can be used to improve the current set of Nilsson parameters in the N = 3 and N = 4 oscillator shells.
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9. |
- Gellanki, Jnaneswari, et al.
(author)
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High-spin Structure Studies in 62Zn
- 2012
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In: Physica Scripta. - 0031-8949. ; T150
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Journal article (peer-reviewed)abstract
- A detailed experimental study of the Zn-62 nucleus was conducted by combining the data sets from four fusion-evaporation reaction experiments. Apart from the previous published data, the present results include ten new rotational band structures and two new superdeformed bands. The GAMMASPHERE Ge-detector array in conjunction with the 4 pi charged-particle detector array Microball allowed for detection of gamma-rays in coincidence with evaporated light particles. The deduced level scheme includes some 260 excited states, which are connected with 450 gamma-ray transitions. The multipolarities have been assigned via directional correlations of gamma-rays emitted from oriented states. The experimental characteristics of the rotational bands are analyzed and compared with the results from the cranked Nilsson-Strutinsky calculations.
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10. |
- Kumari, Renu, et al.
(author)
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Artificial synaptic characteristics of PVA:ZnO nanocomposite memristive devices
- 2023
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In: APL Materials. - Melville : American Institute of Physics (AIP). - 2166-532X. ; 11:10
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Journal article (peer-reviewed)abstract
- Computational efficiency is significantly enhanced using artificial neural network-based computing. A two-terminal memristive device is a powerful electronic device that can mimic the behavior of a biological synapse in addition to storing information and performing logic operations. This work focuses on the fabrication of a memristive device that utilizes a resistive switching layer composed of polyvinyl alcohol infused with ZnO nanoparticles. By incorporating ZnO nanoparticles into the polymer film, the fabricated memristive devices exhibit functionalities that closely resemble those of biological synapses, including short-term and long-term plasticity, paired-pulse facilitation, and spike time-dependent plasticity. These findings establish the ZnO nanoparticle-polymer nanocomposite as a highly promising material for future neuromorphic systems. © 2023 Author(s).
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11. |
- Lalović, Nataša, et al.
(author)
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Study of isomeric states in 198,200,202,206Pb and 206Hg populated in fragmentation reactions
- 2018
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In: Journal of Physics G: Nuclear and Particle Physics. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 45:3
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Journal article (peer-reviewed)abstract
- Isomeric states in isotopes in the vicinity of doubly-magic 208Pb were populated following reactions of a relativistic 208Pb primary beam impinging on a 9Be fragmentation target. Secondary beams of 198,200,202,206Pb and 206Hg were isotopically separated and implanted in a passive stopper positioned in the focal plane of the GSI Fragment Separator. Delayed γ rays were detected with the Advanced Gamma Tracking Array (AGATA). Decay schemes were re-evaluated and interpreted with shell-model calculations. The momentum-dependent population of isomeric states in the two-nucleon hole nuclei 206Pb/206Hg was found to differ from the population of multi neutron-hole isomeric states in 198,200,202Pb.
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12. |
- Rees, J. M., et al.
(author)
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High-spin terminating states in the N=88 Ho-155 and Er-156 isotones
- 2015
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In: Physical Review C (Nuclear Physics). - 0556-2813. ; 91:5
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Journal article (peer-reviewed)abstract
- The Sn-124(Cl-37, 6n gamma) fusion-evaporation reaction at a bombarding energy of 180 MeV has been used to significantly extend the excitation level scheme of Ho-155(67)88. The collective rotational behavior of this nucleus breaks down above spin I similar to 30 and a fully aligned noncollective (band terminating) state has been identified at I-pi = 79/2(-). Comparison with cranked Nilsson-Strutinsky calculations also provides evidence for core-excited noncollective states at I-pi = 87/2(-) and (89/2(+)) involving particle-hole excitations across the Z = 64 shell gap. A similar core-excited state in Er-156(68)88 at I-pi = (46(+)) is also presented.
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13. |
- Wendt, A., et al.
(author)
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Isospin Symmetry in the sd Shell: Transition Strengths in the Neutron-deficient sd Shell Nucleus 33Ar
- 2014
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In: Physical Review C (Nuclear Physics). - 0556-2813. ; 90:5
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Journal article (peer-reviewed)abstract
- Reduced transition strengths of the deexciting transitions from the first two excited states in 33Ar were measured in a relativistic Coulomb excitation experiment at the GSI Helmholtz center. The radioactive ion beam was produced by fragmentation of a primary 36Ar beam on a 9Be target followed by the selection of the reaction product of interest via the GSI Fragment Separator. The 33Ar beam hit a secondary 197Au target with an energy of approximately 145 MeV/nucleon. An array of high-purity germanium cluster detectors and large-volume BaF2 scintillator detectors were employed for γ -ray spectroscopy at the secondary target position. The Lund-York-Cologne Calorimeter was used to track the outgoing ions and to identify the nuclear reaction channels. For the two lowest energy excited states of 33Ar the reduced transition strengths have been determined. With these first results the Tz = −3/2 nucleus 33Ar is now, together with 21Na (Tz = −1/2), the only neutron-deficient odd-A sd shell nucleus in which experimental transition strengths are available. The experimental values are compared to results of shell-model calculations which describe simultaneously mirror-energy differences and transition-strength values of mirror pairs in the sd shell in a consistent way.
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