ISSN:
1434-601X
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract The beta strength function has been calculated for ∼6000 nuclei between the line of beta stability and the neutron drip line. The calculations — performed by using a schematical Brown-Bolsterli model — yield more reliable beta decay half lives,P n values andβ-delayed fission rates than the strongly oversimplified assumptions on Sβ used up to now in astrophysical calculations. The calculated beta rates are shown in this paper to be decisive in the discussion of the problem of the astrophysical site of ther-process, which is responsible for the production of the heavy elements in the universe. In particular we concentrate on the neutron capture processes during the explosive burning of He in massive stars, initiated by the outgoing shock wave from a supernova explosion. It is shown that as consequence of the revisedβ-decay rates explosive He-burning represents a very convincing alternative scenario to the classicalr-process, which avoids the presently existing problems of the latter: 1. The computed relative abundances ofr-nuclei resemble on the average their solar system counterparts. 2. The calculated abundance peaks essentially coincide in position with the observed ones. 3. The new site of ther-process avoids the problems of overproduction of heavy elements and of the mass-cut. Our results are based on realistic stellar models and hydrodynamical explosion calculations which for the first time are applied here to the problem of heavy element nucleosynthesis. The results turn out to be rather insensitive to the details of those models. The shorterβ-decay half lives obtained are of importance also in the investigation of further astrophysical sites producing heavy elements such as then-processes in explosive C or Ne burning.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01443939