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Peter Moller - One of the best experts on this subject based on the ideXlab platform.
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impact of individual nuclear masses on r process abundances
Physical Review C, 2015Co-Authors: M R Mumpower, Peter Moller, R Surman, D L Fang, M Beard, T Kawano, A AprahamianAbstract:We have performed for the first time a comprehensive study of the sensitivity of $r$-process nucleosynthesis to individual nuclear masses across the chart of nuclides. Using the latest version (2012) of the Finite-Range Droplet Model, we consider mass variations of $\ifmmode\pm\else\textpm\fi{}0.5$ MeV and propagate each mass change to all affected quantities, including $Q$ values, reaction rates, and branching ratios. We find such mass variations can result in up to an order of magnitude local change in the final abundance pattern produced in an $r$-process simulation. We identify key nuclei whose masses have a substantial impact on abundance predictions for hot, cold, and neutron star merger $r$-process scenarios and could be measured at future radioactive beam facilities.
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A high-entropy-wind r-process study based on nuclear-structure quantities from the new finite-range Droplet Model FRDM(2012)
The Astrophysical Journal, 2014Co-Authors: Karlludwig Kratz, K Farouqi, Peter MollerAbstract:Attempts to explain the source of r-process elements in our solar system (S.S.) by particular astrophysical sites still face entwined uncertainties, stemming from the extrapolation of nuclear properties far from stability, inconsistent sources of different properties (e.g., nuclear masses and β-decay properties), and the poor understanding of astrophysical conditions, which are hard to disentangle. In this paper we present results from the investigation of r-process in the high-entropy wind (HEW) of core-collapse supernovae (here chosen as one of the possible scenarios for this nucleosynthesis process), using new nuclear-data input calculated in a consistent approach, for masses and β-decay properties from the new finite-range Droplet Model FRDM(2012). The accuracy of the new mass Model is 0.56 MeV with respect to AME2003, to which it was adjusted. We compare the new HEW r-process abundance pattern to the latest S.S. r-process residuals and to our earlier calculations with the nuclear-structure quantities based on FRDM(1992). Substantial overall and specific local improvements in the calculated pattern of the r-process between A ≅ 110 and {sup 209}Bi, as well as remaining deficiencies, are discussed in terms of the underlying spherical and deformed shell structure far from stability.
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a high entropy wind r process study based on nuclear structure quantities from the new finite range Droplet Model frdm 2012
arXiv: Solar and Stellar Astrophysics, 2014Co-Authors: Karlludwig Kratz, K Farouqi, Peter MollerAbstract:Theoretical studies of the nucleosynthesis origin of the heavy elements in our Solar System (S.S.) by the rapid neutron-capture process (r-process) still face the entwined uncertainties in the possible astrophysical scenarios and the nuclear-physics properties far from stability. In this paper we present results from the investigation of an r-process in the high-entropy wind (HEW) of core-collapse supernovae (here chosen as one of the possible scenarios for this nucleosynthesis process), using new nuclear-data input calculated in a consistent approach, for masses and $\beta$-decay properties from the new finite-range Droplet Model FRDM(2012). The accuracy of the new mass Model is 0.56 MeV with respect to {\sc AME2003}, to which it was adjusted. We compare the new HEW r-process abundance pattern to the latest S.S. r-process residuals and to our earlier calculations with the nuclear-structure quantities based on FRDM(1992). Substantial overall and specific local improvements in the calculated pattern of the r-process between $A\simeq 110$ and $^{209}$Bi, as well as remaining deficiencies are discussed in terms of the underlying spherical and deformed shell structure far from stability.
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new finite range Droplet mass Model and equation of state parameters
Physical Review Letters, 2012Co-Authors: Peter Moller, William Myers, H Sagawa, Satoshi YoshidaAbstract:The parameters in the macroscopic Droplet part of the finite-range Droplet Model (FRDM) are related to the properties of the equation of state. In the FRDM (1992) version, the optimization of the Model parameters was not sufficiently sensitive to variations of the compressibility constant $K$ and the density-symmetry constant $L$ to allow their determination. In the new, more accurate FRDM-2011a adjustment of the Model constants to new and more accurate experimental masses allows the determination of $L$ together with the symmetry-energy constant $J$. The optimization is still not sensitive to $K$ which is therefore fixed at $K=240\text{ }\text{ }\mathrm{MeV}$. Our results are $J=32.5\ifmmode\pm\else\textpm\fi{}0.5\text{ }\text{ }\mathrm{MeV}$ and $L=70\ifmmode\pm\else\textpm\fi{}15\text{ }\text{ }\mathrm{MeV}$ and a considerably improved mass-Model accuracy $\ensuremath{\sigma}=0.5700\text{ }\text{ }\mathrm{MeV}$, with respect to the 2003 Atomic Mass Evaluation (AME2003) for FRDM-2011a, compared to $\ensuremath{\sigma}=0.669\text{ }\text{ }\mathrm{MeV}$ for FRDM (1992).
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nuclear properties for astrophysical and radioactive ion beam applications
Atomic Data and Nuclear Data Tables, 1997Co-Authors: Peter Moller, J R Nix, K L KratzAbstract:Abstract We tabulate the ground-state odd-proton and odd-neutron spins and parities, proton and neutron pairing gaps, one- and two-neutron separation energies, quantities related to β -delayed one- and two-neutron emission probabilities, average energy and average number of emitted neutrons, β -decay energy release and half-life with respect to Gamow–Teller decay with a phenomenological treatment of first-forbidden decays, one- and two-proton separation energies, and α -decay energy release and half-life for 9318 nuclei ranging from 16O to 339136 and extending from the proton drip line to the neutron drip line. This paper is a new and improved version of Atomic Data And Nuclear Data Tables [66 131 (1997)]. The starting point of our present work is the new study (FRDM(2012)) of nuclear ground-state masses and deformations based on the finite-range Droplet Model and folded-Yukawa single-particle potential published in a previous issue of Atomic Data And Nuclear Data Tables [109–110, 1 (2016)]. The β -delayed neutron-emission probabilities and Gamow–Teller β -decay rates are obtained from a quasi-particle random-phase approximation with single-particle levels and wave functions at the calculated nuclear ground-state shapes as input quantities. A development since 1997 is we now use a Hauser–Feshbach approach to account for (n, γ ) competition and treat first-forbidden decay in a phenomenological approach.
Yuji Mochizuki - One of the best experts on this subject based on the ideXlab platform.
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fragment molecular orbital based molecular dynamics fmo md method with mp2 gradient
Chemical Physics Letters, 2011Co-Authors: Yuji Mochizuki, Yuto Komeiji, Yoshio Okiyama, Tatsuya Nakano, Katsumi Yamashita, Hikaru Yoshikawa, Hiroshi YamatakaAbstract:Abstract The energy gradient of the second-order Moller–Plesset perturbation theory (MP2) has been implemented in conjunction with the fragment molecular orbital-based molecular dynamics (FMO-MD) method including up to three-body correction (FMO3). A hybrid integral-direct approach of both atomic and molecular orbital indices was utilized with parallelism for the gradient calculations. A Droplet Model consisting of 64 water molecules was then simulated with the 6-31G ∗ basis set. The first peak position of O–O radial distribution function was evaluated to be 2.75 A at the FMO3-MP2 level, whereas the corresponding Hartree–Fock (FMO3-HF) value was 2.89 A. Comparison with an X-ray value of 2.73 A indicated better reliability of the MP2 gradient for FMO-MD.
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fragment molecular orbital based molecular dynamics fmo md simulations on hydrated zn ii ion
Chemical Physics Letters, 2010Co-Authors: Takayuki Fujiwara, Yuji Mochizuki, Yuto Komeiji, Yoshio Okiyama, Hirotoshi Mori, Tatsuya Nakano, Eisaku MiyoshiAbstract:Abstract Recently, the method of fragment molecular orbital-based molecular dynamics (FMO-MD) was enhanced by including the three-body corrections (FMO3) [Y. Komeiji, Y. Mochizuki, T. Nakano, Chem. Phys. Lett. 484 (2010) 380]. This simulation protocol was applied to a Droplet Model consisting of a divalent zinc ion and 64 water molecules, in order to investigate the hydration structure in ab initio fashion. The first peak position of the Zn–O radial distribution function (RDF) was evaluated to be 2.05 A at the FMO3-HF/6-31G level of theory, which was in agreement with an X-ray value of 2.06 ± 0.02 A. The coordination number was evaluated to be 6, corresponding to an octahedral coordination.
Karlludwig Kratz - One of the best experts on this subject based on the ideXlab platform.
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A high-entropy-wind r-process study based on nuclear-structure quantities from the new finite-range Droplet Model FRDM(2012)
The Astrophysical Journal, 2014Co-Authors: Karlludwig Kratz, K Farouqi, Peter MollerAbstract:Attempts to explain the source of r-process elements in our solar system (S.S.) by particular astrophysical sites still face entwined uncertainties, stemming from the extrapolation of nuclear properties far from stability, inconsistent sources of different properties (e.g., nuclear masses and β-decay properties), and the poor understanding of astrophysical conditions, which are hard to disentangle. In this paper we present results from the investigation of r-process in the high-entropy wind (HEW) of core-collapse supernovae (here chosen as one of the possible scenarios for this nucleosynthesis process), using new nuclear-data input calculated in a consistent approach, for masses and β-decay properties from the new finite-range Droplet Model FRDM(2012). The accuracy of the new mass Model is 0.56 MeV with respect to AME2003, to which it was adjusted. We compare the new HEW r-process abundance pattern to the latest S.S. r-process residuals and to our earlier calculations with the nuclear-structure quantities based on FRDM(1992). Substantial overall and specific local improvements in the calculated pattern of the r-process between A ≅ 110 and {sup 209}Bi, as well as remaining deficiencies, are discussed in terms of the underlying spherical and deformed shell structure far from stability.
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a high entropy wind r process study based on nuclear structure quantities from the new finite range Droplet Model frdm 2012
arXiv: Solar and Stellar Astrophysics, 2014Co-Authors: Karlludwig Kratz, K Farouqi, Peter MollerAbstract:Theoretical studies of the nucleosynthesis origin of the heavy elements in our Solar System (S.S.) by the rapid neutron-capture process (r-process) still face the entwined uncertainties in the possible astrophysical scenarios and the nuclear-physics properties far from stability. In this paper we present results from the investigation of an r-process in the high-entropy wind (HEW) of core-collapse supernovae (here chosen as one of the possible scenarios for this nucleosynthesis process), using new nuclear-data input calculated in a consistent approach, for masses and $\beta$-decay properties from the new finite-range Droplet Model FRDM(2012). The accuracy of the new mass Model is 0.56 MeV with respect to {\sc AME2003}, to which it was adjusted. We compare the new HEW r-process abundance pattern to the latest S.S. r-process residuals and to our earlier calculations with the nuclear-structure quantities based on FRDM(1992). Substantial overall and specific local improvements in the calculated pattern of the r-process between $A\simeq 110$ and $^{209}$Bi, as well as remaining deficiencies are discussed in terms of the underlying spherical and deformed shell structure far from stability.
K Farouqi - One of the best experts on this subject based on the ideXlab platform.
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A high-entropy-wind r-process study based on nuclear-structure quantities from the new finite-range Droplet Model FRDM(2012)
The Astrophysical Journal, 2014Co-Authors: Karlludwig Kratz, K Farouqi, Peter MollerAbstract:Attempts to explain the source of r-process elements in our solar system (S.S.) by particular astrophysical sites still face entwined uncertainties, stemming from the extrapolation of nuclear properties far from stability, inconsistent sources of different properties (e.g., nuclear masses and β-decay properties), and the poor understanding of astrophysical conditions, which are hard to disentangle. In this paper we present results from the investigation of r-process in the high-entropy wind (HEW) of core-collapse supernovae (here chosen as one of the possible scenarios for this nucleosynthesis process), using new nuclear-data input calculated in a consistent approach, for masses and β-decay properties from the new finite-range Droplet Model FRDM(2012). The accuracy of the new mass Model is 0.56 MeV with respect to AME2003, to which it was adjusted. We compare the new HEW r-process abundance pattern to the latest S.S. r-process residuals and to our earlier calculations with the nuclear-structure quantities based on FRDM(1992). Substantial overall and specific local improvements in the calculated pattern of the r-process between A ≅ 110 and {sup 209}Bi, as well as remaining deficiencies, are discussed in terms of the underlying spherical and deformed shell structure far from stability.
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a high entropy wind r process study based on nuclear structure quantities from the new finite range Droplet Model frdm 2012
arXiv: Solar and Stellar Astrophysics, 2014Co-Authors: Karlludwig Kratz, K Farouqi, Peter MollerAbstract:Theoretical studies of the nucleosynthesis origin of the heavy elements in our Solar System (S.S.) by the rapid neutron-capture process (r-process) still face the entwined uncertainties in the possible astrophysical scenarios and the nuclear-physics properties far from stability. In this paper we present results from the investigation of an r-process in the high-entropy wind (HEW) of core-collapse supernovae (here chosen as one of the possible scenarios for this nucleosynthesis process), using new nuclear-data input calculated in a consistent approach, for masses and $\beta$-decay properties from the new finite-range Droplet Model FRDM(2012). The accuracy of the new mass Model is 0.56 MeV with respect to {\sc AME2003}, to which it was adjusted. We compare the new HEW r-process abundance pattern to the latest S.S. r-process residuals and to our earlier calculations with the nuclear-structure quantities based on FRDM(1992). Substantial overall and specific local improvements in the calculated pattern of the r-process between $A\simeq 110$ and $^{209}$Bi, as well as remaining deficiencies are discussed in terms of the underlying spherical and deformed shell structure far from stability.
Heinz Pitsch - One of the best experts on this subject based on the ideXlab platform.
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theoretical single Droplet Model for particle formation in flame spray pyrolysis
Energy & Fuels, 2021Co-Authors: Yihua Ren, Jinzhi Cai, Heinz PitschAbstract:Flame spray pyrolysis has emerged as a promising technology to synthesize metal-oxide nanomaterials in a scalable way. However, numerical simulation of the reactive flow system is challenging due t...
