Characteristics of the shell structure further from stability are most
influential, leading to questions whether for very neutron-rich nuclei
the shell gap at *N*=82 is less pronounced (i.e. quenched) than predicted
by global macroscopic-microscopic mass models like the Finite Range Droplet
Model (FRDM) or the Extended Thomas Fermi approach with Strutinski Integral
(ETFSI) [30]. This has an important
effect on the r-process path and the resulting abundances below the *A*=130
peak. An experimental investigation of shell quenching along *N*=50
and 82 towards lower *Z*'s (and reaching the r-process path at *N*=126
for the very first time) is a highly desirable goal. It will test the nuclear
structure responsible for the abundances of heavy nuclei, improve the understanding
how well **microscopic-macroscopic models, self-consistent microscopic
approaches** or **relativistic mean field theories** can describe
reality and lead to an extensive test of effective forces used for such
calculations [31]. The theoretical studies
of nuclear -decay
properties are based on the spectral distribution of the -decay
transition probability (the -strength
function). For the short-lived nuclides on the r- and rp-process paths,
the approximation of allowed Gamov-Teller (GT) transitions is usually accurate
enough. Microscopic models like the proton-neutron quasiparticle random
phase approximation (**QRPA**) are generally used, based on empirical
or self-consistent one-body single-particle potentials, a pairing interaction,
and a spin-isospin effective NN-interaction [32].
Thus, this approach is based on single-particle spectra and their uncertainties.
Therefore, beta-decay properties are another testing ground for self-consistent
mean-field approaches which can be significantly improved if the form and
parameters of the corresponding density functionals or effective forces
are fitted not only to the nuclear ground state properties near the stability,
but also to those of doubly-magic unstable nuclides. Further studies in
the regions of ^{78}Ni and ^{132}Sn at RIB facilities and
high-flux nuclear reactors will be extremely helpful.

Explosive nuclear burning also requires the ability to predict reaction
cross sections with the aid of theoretical models. Especially for light
nuclei, microscopic cluster models can be applied [33].
A high level density in the compound nucleus at the appropriate excitation
energy allows to make use of the statistical model approach. For the majority
of nuclei in astrophysical applications the necessary experimental information
(on e.g. **optical potentials for particle and alpha transmission coefficients,
level densities, resonance energies and widths of giant resonances**
- to be implemented in predicting E1 and M1 gamma-transitions) is not available.
The real challenge is thus to predict all these necessary ingredients [14].
Standard spectroscopic methods can be utilised in connection with RIB's
to assess level densities and giant resonance properties, scattering experiments
for determining optical potentials.

NuPECC WebForce,