arXiv subjects

C. Fröhlich

Publications and source records attributed to C. Fröhlich.

21 records · Page 2Linked to original sources

arXiv2005

Neutrino-induced nucleosynthesis of A>64 nuclei: The nu p-process

We present a new nucleosynthesis process, that we denote nu p-process, which occurs in supernovae (and possibly gamma-ray bursts) when strong neutrino fluxes create proton-rich ejecta. In this process, antineutrino absorptions in the proton-rich environment produce neutrons that are immediately captured by neutron-deficient nuclei. This allows for the nucleosynthesis of nuclei with mass numbers A >64. Making this process a possible candidate to explain the origin of the solar abundances of 92,94Mo and 96,98Ru. This process also offers a natural explanation for the large abundance of Sr seen in an hyper-metal-poor star.

astro-ph↗

arXiv2004

The Innermost Ejecta of Core Collapse Supernovae

We ensure successful explosions (of otherwise non-explosive models) by enhancing the neutrino luminosity via reducing the neutrino scattering cross sections or by increasing the heating efficiency via enhancing the neutrino absorption cross sections in the heating region. Our investigations show that the resulting electron fraction Ye in the innermost ejecta is close to 0.5, in some areas even exceeding 0.5. We present the effects of the resulting values for Ye on the nucleosynthesis yields of the innermost zones of core collapse supernovae.

astro-ph↗

arXiv2003

Resonance analysis of $^{147}$Sm(n,alpha) cross sections: Comparison to optical model calculations and indications of non-statistical effects

We have measured the $^{147}$Sm(\textit{n},$α$) cross section from 3 eV to 500 keV and performed an $\mathcal{R}$-matrix analysis in the resolved region ($E_{n}$$<$ 700 eV) to extract $α$ widths for 104 resonances. We computed strength functions from these resonance parameters and compared them to transmission coefficients calculated using optical model potentials similar to those employed as inputs to statistical model calculations. The statistical model often is used to predict cross sections and astrophysical reaction rates. Comparing resonance parameters rather than cross sections allows more direct tests of potentials used in the model and hence should offer greater insight into possible improvements. In particular, an improved $α$+nucleus potential is needed for applications in nuclear astrophysics. In addition to providing a more direct test of the $α$% +nucleus potential, the $α$-width distributions show indications of non-statistical effects.

astro-ph↗