Mon·Oct 16, 2023Monday·October 16, 2023

1. 01*

   The intermediate neutron capture process: IV. Impact of nuclear model and parameter uncertainties

   S. Martinet🇧🇪 · A. Choplin🇧🇪 · S. Goriely🇧🇪 · L. Siess

   We investigate both the systematic and statistical uncertainties associated with theoretical nuclear reaction rates of relevance during the i-process and explore their impact on the i-process elemental production, and subsequently on the surface enrichment, for a low-mass low-metallicity star during the early AGB phase. We use the TALYS reaction code (Koning et al. 2023) to estimate both the model and parameter uncertainties affecting the photon strength function and the nuclear level densities, hence the radiative neutron capture rates. The STAREVOL code (Siess et al. 2006) is used to determine the impact of nuclear uncertainties on the i-process nucleosynthesis in a 1 $M_{\odot }$ [Fe/H] = - 2.5 model star during the proton ingestion event in the early AGB phase. A large nuclear network of 1160 species coherently coupled to the transport processes is solved to follow the i-process nucleosynthesis. We find that the non-correlated parameter uncertainties lead the surface abundances uncertainties of element with $Z\ge 40$ to range between 0.5 and 1.0 dex, with odd-$Z$ elements displaying higher uncertainties. The correlated model uncertainties are of the same order of magnitude, and both model and parameter uncertainties have an important impact on potential observable tracers such as Eu and La. Both the correlated model and uncorrelated parameter uncertainties need to be estimated coherently before being propagated to astrophysical observables through multi-zone stellar evolution models. Many reactions are found to affect the i-process predictions and will require improved nuclear models guided by experimental constraints. Priority should be given to the reactions influencing the observable tracers.

   ↳ astro-ph.SRnucl-exnucl-thAstron.Astrophys.(2024)·16 citations
2. 02*

   Overview and performance of the 2023 MUGAST@LISE campaign at GANIL

   V. Girard-Alcindor🇫🇷 · H. Jacob🇫🇷 · M. Assié🇫🇷 · D. Beaumel🇫🇷 · Y. Blumenfeld🇫🇷

   MUGAST is a state-of-the-art silicon array combining trapezoidal and square shaped double-sided silicon strip detectors (DSSD) to four MUST2 telescopes. Coupled to a {\gamma}-ray spectrometer, the excellent angular coverage and compacity of the MUGAST array make it an ideal tool for the study of transfer reactions. It is a first step toward the development of the new generation of silicon arrays using pulse shape analysis (PSA) for particle identification, such as the future GRIT array developed by our collaboration. In recent years, MUGAST has been widely used at GANIL. First with the AGATA {\gamma}-ray spectrometer and the VAMOS large acceptance spectrometer for the study of ISOL beams from the SPIRAL1 facility. It is now coupled with twelve EXOGAM clovers and to a new zero degree detection system at the end of the LISE fragmentation beamline.

   ↳ physics.ins-detnucl-exNuovo Cim.C(2024)·2 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.