Related papers: Nuclear Processes at Solar Energy
Nuclear reactions transform atomic nuclei inside stars. This is the process of stellar nucleosynthesis. The basic concepts of determining nuclear reaction rates inside stars are reviewed. How stars manage to burn their fuel so slowly most…
A general decomposition of the amplitudes for the $2\to 2$ processes $\gamma\nu\to\gamma\nu$ and $\gamma\gamma\to\nu\bar{\nu}$ is obtained using gauge invariance and Bose symmetry. The restrictions implied by this decomposition are…
We discuss microscopic cluster model descriptions of two solar nuclear reactions, Be7(p,gamma)B8 and He3(He3,2p)He4. The low-energy reaction cross section of Be7(p,gamma)B8, which determines the high-energy solar neutrino flux, is…
The synthesis of nuclei in diverse cosmic scenarios is reviewed, with a summary of the basic concepts involved before a discussion of the current status in each case is made. We review the physics of the early universe, the proton to…
A cubic kilometer scale experiment has been proposed to detect cosmic neutrinos of energy from tens of GeV up to the highest energies observed for cosmic rays, around 10**20 eV, or possibly even beyond. Detection efficiencies depend…
Nucleosynthesis beyond Fe poses additional challenges not encountered when studying astrophysical processes involving light nuclei. Generally higher temperatures and nuclear level densities lead to stronger contributions of transitions on…
The cross sections of nuclear reactions between the radioisotope $^7$Be and deuterium, a possible mechanism of reducing the production of mass-7 nuclides in Big-Bang nucleosynthesis, were measured at center-of-mass energies between 0.2 MeV…
Two models are presented for the description of the electron screening effects that appear in laboratory nuclear reactions at astrophysical energies. The two-electron screening energy of the first model agrees very well with the recent LUNA…
We study charged-current neutrino cross sections on neutronrich nuclei in the mass $A\sim60$ region. Special attention is paid to environmental effects, i.e. finite temperature and density, on the cross sections. As these effects are…
The $\gamma$-process in core-collapse and/or type Ia supernova explosions is thought to explain the origin of the majority of the so-called $p$ nuclei (the 35 proton-rich isotopes between Se and Hg). Reaction rates for $\gamma$-process…
The description of the inelastic proton -- nucleus cross section at very high energies is still an open question. The current theoretical uncertainty has direct impact on the predictions of the cosmic ray and neutrino physics observables.…
The electron capture process plays an important role in the evolution of the core collapse of a massive star that precedes the supernova explosion. In this study, the electron capture on nuclei in stellar environment is described in the…
The experimental study of nuclear reactions of astrophysical interest is greatly facilitated by a low-background, high-luminosity setup. The Laboratory for Underground Nuclear Astrophysics (LUNA) 400 kV accelerator offers ultra-low…
Properties of atomic nuclei important for the prediction of astrophysical reaction rates are reviewed. In the first part, a recent simulation of evolution and nucleosynthesis of stars between 15 and 25 solar masses is presented. This study…
Study of the fusion reactions between hydrogen isotopes in muonic molecules is the first example of the accurate accounting of the nucleus charge screening by a muon in the fusion process. At LUNA installation the measurements of…
Core collapse supernovae are dominated by energy transport from neutrinos. Therefore, some supernova properties could depend on symetries and features of the standard model weak interactions. The cross section for neutrino capture is larger…
Cross sections for the strongest gamma-ray emission lines produced in alpha-particle reactions with C, Mg, Si, Fe have been measured in the range E_alpha = 50 - 90 MeV at the center for proton therapy at the Helmholtz-Zentrum Berlin. Data…
Neutrino interactions with protons and neutrons probe their deep structure and may reveal new physics. The higher the neutrino energy, the sharper the probe. So far, the neutrino-nucleon ($\nu N$) cross section is known across neutrino…
The nuclear level densities and $\gamma$-ray strength functions of $^{138,139,140}$La were measured using the $^{139}$La($^{3}$He, $\alpha$), $^{139}$La($^{3}$He, $^{3}$He$^\prime$) and $^{139}$La(d, p) reactions. The particle-$\gamma$…
A possible mechanism to explain the origin of the light $p$-nuclei in the Galaxy is the nucleosynthesis in the proton-rich neutrino-driven wind ejecta of core-collapse supernovae via the $\nu p$-process. However this production scenario is…