Neutron capture rates in the r-process - The role of direct radiative capture

1983 ◽  
Vol 270 ◽  
pp. 740 ◽  
Author(s):  
G. J. Mathews ◽  
A. Mengoni ◽  
F.-K. Thielemann ◽  
W. A. Fowler
Keyword(s):  
Neutron Capture ◽  
Radiative Capture ◽  
R Process ◽  
Capture Rates

scholarly journals Sensitivity studies for the weak r process: neutron capture rates

AIP Advances ◽  
2014 ◽  
Vol 4 (4) ◽  
pp. 041008 ◽  
Author(s):  
R. Surman ◽  
M. Mumpower ◽  
R. Sinclair ◽  
K. L. Jones ◽  
W. R. Hix ◽  
...  
Keyword(s):  
Neutron Capture ◽  
Sensitivity Studies ◽  
R Process ◽  
Capture Rates

scholarly journals NEUTRON CAPTURE RATES AND r-PROCESS NUCLEOSYNTHESIS

2013 ◽  
Author(s):  
R. A. SURMAN ◽  
M. R. MUMPOWER ◽  
G. C. MCLAUGHLIN ◽  
R. SINCLAIR ◽  
W. R. HIX ◽  
...  
Keyword(s):  
Neutron Capture ◽  
R Process ◽  
Capture Rates

scholarly journals Study of the neutron and proton capture reactions 10,11B(n, γ), 11B(p, γ), 14C(p, γ), and 15N(p, γ) at thermal and astrophysical energies

2014 ◽  
Vol 23 (08) ◽  
pp. 1430012 ◽  
Author(s):  
Sergey Dubovichenko ◽  
Albert Dzhazairov-Kakhramanov
Keyword(s):  
Experimental Data ◽  
Cross Sections ◽  
Neutron Capture ◽  
Proton Capture ◽  
Total Cross Sections ◽  
Resonance Behavior ◽  
S Factor ◽  
Scattering Phase ◽  
R Process

We have studied the neutron-capture reactions 10,11 B (n, γ) and the role of the 11 B (n, γ) reaction in seeding r-process nucleosynthesis. The possibility of the description of the available experimental data for cross-sections of the neutron capture reaction on 10 B at thermal and astrophysical energies, taking into account the resonance at 475 keV, was considered within the framework of the modified potential cluster model (MPCM) with forbidden states (FS) and accounting for the resonance behavior of the scattering phase shifts. In the framework of the same model, the possibility of describing the available experimental data for the total cross-sections of the neutron radiative capture on 11 B at thermal and astrophysical energies were considered with taking into account the 21 and 430 keV resonances. Description of the available experimental data on the total cross-sections and astrophysical S-factor of the radiative proton capture on 11 B to the GS of 12 C was treated at astrophysical energies. The possibility of description of the experimental data for the astrophysical S-factor of the radiative proton capture on 14 C to the GS of 15 N at astrophysical energies, and the radiative proton capture on 15 N at the energies from 50 to 1500 keV was considered in the framework of the MPCM with the classification of the orbital states according to Young tableaux. It was shown that, on the basis of the M1 and the E1 transitions from different states of the p15 N scattering to the GS of 16 O in the p15 N channel, it is quite succeed to explain general behavior of the S-factor in the considered energy range in the presence of two resonances.

Reduction of the neutron imaginary potential off the stability line and its possible impact on neutron capture rates

2021 ◽  
Vol 104 (1) ◽  
Author(s):  
A. V. Voinov ◽  
K. Brandenburg ◽  
C. R. Brune ◽  
R. Giri ◽  
S. M. Grimes ◽  
...  
Keyword(s):  
Neutron Capture ◽  
Imaginary Potential ◽  
The Stability ◽  
Capture Rates ◽  
Stability Line

scholarly journals The role of fission on neutron star mergers and its impact on the r-process peaks

2016 ◽  
Author(s):  
M. Eichler ◽  
A. Arcones ◽  
A. Kelic ◽  
O. Korobkin ◽  
K. Langanke ◽  
...  
Keyword(s):  
Neutron Star ◽  
R Process

60Fe and 244Pu deposited on Earth constrain the r-process yields of recent nearby supernovae

Science ◽  
2021 ◽  
Vol 372 (6543) ◽  
pp. 742-745
Author(s):  
A. Wallner ◽  
M. B. Froehlich ◽  
M. A. C. Hotchkis ◽  
N. Kinoshita ◽  
M. Paul ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Neutron Stars ◽  
Neutron Capture ◽  
Half Life ◽  
Massive Stars ◽  
Chemical Elements ◽  
Capture Process ◽  
Isotopic Signatures ◽  
Supernova Explosions ◽  
R Process

Half of the chemical elements heavier than iron are produced by the rapid neutron capture process (r-process). The sites and yields of this process are disputed, with candidates including some types of supernovae (SNe) and mergers of neutron stars. We search for two isotopic signatures in a sample of Pacific Ocean crust—iron-60 (60Fe) (half-life, 2.6 million years), which is predominantly produced in massive stars and ejected in supernova explosions, and plutonium-244 (244Pu) (half-life, 80.6 million years), which is produced solely in r-process events. We detect two distinct influxes of 60Fe to Earth in the last 10 million years and accompanying lower quantities of 244Pu. The 244Pu/60Fe influx ratios are similar for both events. The 244Pu influx is lower than expected if SNe dominate r-process nucleosynthesis, which implies some contribution from other sources.

scholarly journals Constraining nucleosynthesis in two CEMP progenitors using fluorine

2020 ◽  
Vol 498 (3) ◽  
pp. 3549-3559
Author(s):  
Aldo Mura-Guzmán ◽  
D Yong ◽  
C Abate ◽  
A Karakas ◽  
C Kobayashi ◽  
...  
Keyword(s):  
Neutron Capture ◽  
Slow Neutron ◽  
Asymptotic Giant Branch ◽  
Capture Process ◽  
Upper Limit ◽  
Infrared Spectrometer ◽  
Binary Evolution ◽  
Vibration Rotation ◽  
R Process ◽  
Process Elements

ABSTRACT We present new fluorine abundance estimations in two carbon enhanced metal-poor (CEMP) stars, HE 1429−0551 and HE 1305+0007. HE 1429−0551 is also enriched in slow neutron-capture process (s-process) elements, a CEMP-s, and HE 1305+0007 is enhanced in both, slow and rapid neutron-capture process elements, a CEMP-s/r. The F abundances estimates are derived from the vibration–rotation transition of the HF molecule at 23358.6 Å  using high-resolution infrared spectra obtained with the Immersion Grating Infrared Spectrometer (IGRINS) at the 4-m class Lowell Discovery Telescope. Our results include an F abundance measurement in HE 1429−0551 of A(F) = +3.93 ([F/Fe] = +1.90) at [Fe/H] = −2.53, and an F upper limit in HE 1305+0007 of A(F) < +3.28 ([F/Fe] < +1.00) at [Fe/H] = −2.28. Our new derived F abundance in HE 1429−0551 makes this object the most metal-poor star where F has been detected. We carefully compare these results with literature values and state-of-the-art CEMP-s model predictions including detailed asymptotic giant branch (AGB) nucleosynthesis and binary evolution. The modelled fluorine abundance for HE 1429−0551 is within reasonable agreement with our observed abundance, although is slightly higher than our observed value. For HE 1429−0551, our findings support the scenario via mass transfer by a primary companion during its thermally pulsing phase. Our estimated upper limit in HE 1305+0007, along with data from the literature, shows large discrepancies compared with AGB models. The discrepancy is principally due to the simultaneous s- and r-process element enhancements which the model struggles to reproduce.

Sign in / Sign up

Export Citation Format

Share Document