The Impact of Fission on R-Process Calculations

6th Nuclear Physics in Astrophysics

物理学;天文学

Eichler, M.^1 ; Arcones, A.^2 ; Käppeli, R.^3 ; Korobkin, O.^4 ; Liebendörfer, M.^1 ; Martinez-Pinedo, G.^2 ; Panov, I.V.^5 ; Rauscher, T.^1,6 ; Rosswog, S.^4 ; Thielemann, F.-K.^1 ; Winteler, C.^7

Department of Physics, Basel University, Klingelbergstrasse 82, Basel

4056, Switzerland^1

Institut für Kernphysik, Technische Universität Darmstadt, Schlossgartenstrasse 2, Darmstadt

D-64289, Germany^2

Seminar for Applied Mathematics, ETH Zürich, Rämistrasse 101, Zürich

8092, Switzerland^3

Astronomy, Oskar Klein Centre, Stockholm University, AlbaNova, Stockholm

SE-10691, Sweden^4

Institute for Theoretical and Experimental Physics, Bol'shaya Cheremushkinskaya ul. 25, Moscow

117259, Russia^5

Centre for Astrophysics Research, School of Physics, Astronomy and Mathematics, University of Hertfordshire, Hatfield

AL10 9AB, United Kingdom^6

Institut Energie Am Bau, Fachhochschule Nordwestschweiz, St. Jakobs-Strasse 84, Muttenz

4132, Switzerland^7

关键词: Abundance distribution;    Fission barrier;    Fission fragment;    Neutron capture;    Nuclear mass models;    Parametrizations;    Separation energy;    Statistical treatment;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/665/1/012054/pdf
DOI  :  10.1088/1742-6596/665/1/012054

学科分类：天文学(综合)

来源: IOP

【 摘 要 】

We have performed r-process calculations in neutron star mergers (NSM) and jets of magnetohydrodynamically driven (MHD) supernovae. In these very neutron-rich environments the fission model of heavy nuclei has an impact on the shape of the final abundance distribution and the second r-process peak in particular. We have studied the effect of different fission fragment mass distribution models in calculations of low-Yeejecta, ranging from a simple parametrization to extensive statistical treatments (ABLA07). The r-process path ends when it reaches an area in the nuclear chart where fission dominates over further neutron captures. The position of this point is determined by the fission barriers and the neutron separation energies of the nuclei involved. As these values both depend on the choice of the nuclear mass model, so does the r-process path. Here we present calculations using the FRDM (Finite Range Droplet Model) and the ETFSI (Extended Thomas Fermi with Strutinsky Integral) mass model with the related TF and ETFSI fission barrier predictions. Utilizing sophisticated fission fragment distribution leads to a highly improved abundance distribution.