Stellar krypton cross sections at<i>kT=25</i>and 52 keV

Käppeler, F.; Naqvi, A.A.; Al-Ohali, M.A.

doi:10.1103/physrevc.35.936

Cited by 38 publications

(38 citation statements)

References 9 publications

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“…Similar to the branching at 85 Kr, this branching is also independent of stellar temperature and hence, the isotopic ratio of 94 Zr to 96 Zr can predict the stellar neutron density condition. The two isotopes 94,96 Zr suffer from overabundance problem. The s-process also contributes slightly to the production of 96 Zr, which, in general, believed to be r-only isotope [4], due to the branching at 95 Zr at high neutron densities.…”

Section: B Total Capture Cross Sectionsmentioning

confidence: 72%

“…The final MACS values were obtained by renormalizing their values with JENDL-4.0 library data [75] to eliminate the discrepancy for small capture kernels. Cross sections for 94,96 Zr are required the in the analysis of s-process branching at 95 Zr. Similar to the branching at 85 Kr, this branching is also independent of stellar temperature and hence, the isotopic ratio of 94 Zr to 96 Zr can predict the stellar neutron density condition.…”

Section: B Total Capture Cross Sectionsmentioning

confidence: 99%

“…Cross sections for 94,96 Zr are required the in the analysis of s-process branching at 95 Zr. Similar to the branching at 85 Kr, this branching is also independent of stellar temperature and hence, the isotopic ratio of 94 Zr to 96 Zr can predict the stellar neutron density condition. The two isotopes 94,96 Zr suffer from overabundance problem.…”

Section: B Total Capture Cross Sectionsmentioning

confidence: 99%

“…The present study also involves some nuclei produced in astrophysical p-process near N = 50 closed shell ( 84 Sr, 92,94 Mo, 96,98 Ru). The p-nuclei, those are 10 to 100 times less abundant than s-or r-nuclei in the same mass range are produced in the high-temperature environment via the sequences of photo-disintegration and β + decays driving the path through the extreme proton-rich side.…”

Section: Introductionmentioning

confidence: 99%

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Neutron capture reactions relevant to thesandpprocesses in the region of theN=50shell closure

2016

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Radiative thermal neutron capture cross sections for nuclei participating in s-process and pprocess nucleosynthesis in and around N = 50 closed neutron shell have been calculated in statistical semi-microscopic Hauser-Feshbach approach for the energy range of astrophysical interest. A folded optical-model potential is constructed utilizing the standard DDM3Y real nucleon-nucleon interaction. The folding of the interaction with target radial matter densities, obtained from the relativistic-mean-field approach, is done in coordinate space using the spherical approximation. The standard nuclear reaction code TALYS1.8 is used for cross-section calculation. The cross sections are compared with experimental results and reasonable agreements are found for almost all cases. Maxwellian-averaged cross sections (MACS) for the nuclei are presented at a single thermal energy of 30 keV relevant to s-process. We have also presented the MACS values over a range of energy from 5 to 100 keV for neutron magic nuclei with (N = 50).PACS numbers: I. INTRODUCTIONElements heavier than iron are produced via two principle processes, namely, the slow neutron capture process (s-process) and the rapid neutron capture process (r-process), differing in the respective neutron capture timescales with respect to the β-decay half-lives. There is a minor contribution from another process, namely, pprocess, producing a subset of proton-rich isotopes. The detailed study of the heavy element nucleosynthesis was done in the fundamental work of Burbidge et al. [1] and also of Cameron [2]. Recently Käppeler et al. [3] presented a review of progress on the studies of s-process nucleosynthesis with advanced nuclear physics inputs, observational data, and stellar models.While the majority of the theory of the s-process is well-developed, uncertainty still remains in constraining the neutron capture rates of nuclei involved in nucleosynthesis chain. The capture cross sections are highly scattered and uncertain in the energy range appropriate for astrophysical applications. These uncertainties lead to significant errors in determining exact abundances of elements involved in different processes. Many works * Electronic address: saumidutta89@gmail.com † Electronic address: ggphy@caluniv.ac.in ‡ Electronic address: abhattacharyyacu@gmail.com have been devoted to this respect in order to measure the thermal neutron capture cross sections relevant to s-process temperature. However, reactions on some important nuclei are still not available due to their unavailability in the terrestrial laboratory. Käppeler et al. [4] showed the present status of the uncertainty of stellar (n, γ) cross sections and commented that improvements are certainly necessary especially in the mass region below A=120 and above A=180. Some reactions are of significant importance, basically those with closed neutron shells acting as bottlenecks to the s-process reaction flow. They have very low cross-sections and in some scenarios, the s-process reaction flow cannot overcome these bottlen...

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Section: B Total Capture Cross Sectionsmentioning

confidence: 72%

Section: B Total Capture Cross Sectionsmentioning

confidence: 99%

Section: B Total Capture Cross Sectionsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Neutron capture reactions relevant to thesandpprocesses in the region of theN=50shell closure

2016

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“…The thickness of 7 Li targets and the scattered angles of neutrons have been tuned to obtain the neutron beam with the quasi-stellar energy spectrum. The 3 H(p, n) and 18 O(p, n) reactions are also used for kT = 52 keV [24] and 5 keV [25], respectively. For the study of the γ process, Mohr et al proposed a similar method using bremsstrahlung γ-rays [21,26], although the energy distribution of the bremsstrahlung γ-ray differs from the Planck distribution.…”

Section: Direct Measurement Of Stellar Nuclear Reaction Rate On the Gmentioning

confidence: 99%

Explosive Nucleosynthesis Study Using Laser Driven γ-ray Pulses

Hayakawa

Nakamura

Kotaki

et al. 2017

QuBS

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Abstract:We propose nuclear experiments using γ-ray pulses provided from high field plasma generated by high peak power laser. These γ-ray pulses have the excellent features of extremely short pulse, high intensity, and continuous energy distribution. These features are suitable for the study of explosive nucleosyntheses in novae and supernovae, such as the γ process and ν process. We discuss how to generate suitable γ-ray pulses and the nuclear astrophysics involved.

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