Search
Now showing items 1-10 of 11
Activation method combined with characteristic X-ray counting : A possibility to measure (alpha, gamma) cross sections on heavy p-nuclei
(2011-10-01)
For an improved modeling of the astrophysical nucleosynthesis of p-nuclei, low energy cross section data of alpha-induced reactions on heavy isotopes are needed. Technical difficulties hamper the experimental determination ...
Opportunities to constrain astrophysical reaction rates for the s-process via determination of the ground-state cross-sections
(2011-09-10)
Modern models of s-process nucleosynthesis in stars require stellar reaction rates of high precision. Most neutron-capture cross-sections in the s-process have been measured, and for an increasing number of reactions the ...
Au-197(n,gamma) cross section in the unresolved resonance region
(2011-03-17)
The cross section of the reaction Au-197(n,gamma) was measured with the time-of-flight technique at the n_TOF (neutron time-of-flight) facility in the unresolved resonance region between 5 and 400 keV using a pair of C6D6 ...
Stellar (n,gamma) cross sections of p-process isotopes Part I: Pd-102, Te-120, Ba-130,Ba-132, and Dy-156
(2010-01)
We have investigated the (n,gamma) cross sections of p-process isotopes with the activation technique. The measurements were carried out at the Karlsruhe Van de Graaff accelerator using the Li-7(p, n) Be-7 source for ...
Alpha-induced reactions for the astrophysical p-process : the case of (151)Eu
(IOP Publishing Ltd., 2010)
The cross sections of (151)Eu(alpha, gamma)(155)Tb and (151)Eu(alpha,n)(154)Tb reactions have been measured with the activation method. Some aspects of the measurement are presented here to illustrate the requirements of ...
Nuclear physics for the Re/Os clock
(2008-01)
Dating the age of the universe by the beta-decay of (187)Re (t(1/2) = 41.2 Gyr) requires the accurate assessment of the s-process reaction flow. The daughter nucleus (187)Os as well as its immediate s-only neighbor (186)Os ...
Neutron reactions and nuclear cosmo-chronology
(Elsevier, 2007-07)
The beta-decay of Re-187 (t(1/2) = 42.3 Gyr) represents a suited cosmo-chronometer for the age of the r-process abundances, since the radiogenic part of the daughter isotope (OS)-O-187 is defined by the difference between ...
Experimental (n,gamma) cross sections of the p-process nuclei Se-74 and Sr-84
(2006-01)
The nucleosynthesis of elements beyond iron is dominated by the s and r processes. However, a small amount of stable isotopes on the proton-rich side cannot be made by neutron capture and are thought to be produced by ...
Proton induced reaction cross section measurements on Se isotopes for the astrophysical p process
(2003-11)
As a continuation of a systematic study of reactions relevant to the astrophysical p process, the cross sections of the Se-74,Se-76(p,gamma) Br-75,Br-77 and Se-82(p,n) Br-82 reactions have been measured at energies from ...
s-process branchings at Sm-151, Eu-154, and Dy-163
(2001-07)
The (n, gamma) cross sections of the stable europium isotopes Eu-151 and Eu-153 have been measured by irradiating oxide samples in a quasistellar neutron spectrum. From the induced activities, the stellar cross sections ...