Conveners
Poster presentation
- Xiaodong Tang (Institute of Modren Physics, Chinese Academy of Science)
Context. An accurate 28P(p, ฮณ)29S reaction rate is crucial to defining the nucleosynthesis products of explosive hydrogen burning in ONe novae. Using the recently released nuclear mass of 29S, together with a shell model and a direct capture calculation, we reanalyzed the 28P(p, ฮณ)29S thermonuclear reaction rate and its astrophysical implication.
Aims. We focus on improving the...
The thermonuclear reaction rate of $^{57}{\rm Cu}(p,\gamma)^{58}{\rm Zn}$, which depends exponentially on the neutron-deficient nuclide $^{58}$Zn mass, is of great importance to understand how the rp-process proceed beyond the $^{56}$Ni waiting point in type-I X-ray bursts.
So far the uncertainty of $^{57}{\rm Cu}(p,\gamma)^{58}{\rm Zn}$ reaction rate is dominated by the 50~keV uncertainty...
Elements beyond Fe are produced through the process of neutron capture. The s-process is known to occur in a low-mass star as it evolves to an asymptotic giant branch (AGB) star. On the other hand, the r-process is believed to occur in a neutron star merger (NSM). Kolborg et al. (2023) carried out a numerical simulation of the spatial distribution of the r-process element (Eu), and they...
Half of the elements heavier than iron are synthesized by the r-process. The origin of the r-process is still a major matter of debate. Recent studies have shown that the origin of the r-process is neutron star mergers. On the other hand, from the studies of galactic chemical evolution, assuming neutron star mergers as the only r-process sites, it is difficult to explain stellar observations...
The cooling effect of $^{63}$Fe$-$$^{63}$Mn Urca pair on the neutron star surface has been evaluated based on the state-of-the-art shell model calculations which reproduced the experimental spectroscopy results in the neutron-rich N $\sim$ 40 region. It is concluded that $^{63}$Fe$-$$^{63}$Mn could be among the strongest Urca pairs in the neutron star crust. This pair has been identified as...
The $\alpha$p-process, consisting of a series of ($\alpha$,p) and (p,$\gamma$) reactions, plays an important
role in nucleosynthesis during X-ray bursts. Among these reactions, the 26Si($\alpha$,p)29P
reaction is particularly significant due to its substantial impact on the light curve of X-
ray bursts. Despite its importance, experimental data for this reaction remain
insufficient due to...
In thermonuclear reactions of nuclear astrophysical interest, some can produce short-lived products that emit positrons. These positrons will annihilate with electrons in the target and then produce a pair of 511 keV ฮณ-rays, which can be used to determine the reaction yield and calculate the cross-section as well as the astrophysical S-factor. We leverage the back-to-back characteristic of 511...
The CNO cycle is the primary energy production mechanism in massive stars, with the $^{15}$N$(p, \gamma)^{16}$O reaction serving as a crucial branching point connecting the CN and NO cycles. The ratio of reaction rates between $^{15}$N$(p, \gamma)^{16}$O and $^{15}$N$(p,\alpha)^{12}$C directly determines the nitrogen and oxygen abundances within the CNO cycle, which in turn affect stellar...
A core-collapse supernova (CCSN) is an explosive phenomenon that occurs at the end of the life of a massive star and drives the chemical evolution of the Universe by providing metals. However, the explosion mechanism has not yet been fully understood. In this study, we utilize nucleosynthesis to investigate the explosion mechanism. Metal-poor stars are low-mass stars formed in the early...
Single-particle motion of nucleons is quenched by so-called short-range and long-range correlations, which was first observed on some stable nuclei through (e,eโp) and (d, $^3$He) transfer reactions. Systematic studies of Heavy-Ion (HI) induced single-nucleon knockout at intermediate-energy have drawn a surprising conclusion that the quenching factor Rs, simply defined as the ratio of...
Carbon fusion reaction is one of the primary reactions in massive stars. It also serves as the ignition reaction for Type Ia supernova explosions and X-ray superburst. Accurate carbon-carbon fusion reaction rate can reduce uncertainties in massive stars and the ignition condition in Type Ia supernova. It also can resolve the ignition problem in superburst.
However, the carbon-carbon fusion...
The direct measurement of the carbon-carbon fusion reaction cross-section has been conducted at LEAF facility at IMP. In the field of nuclear astrophysics, the carbon-carbon fusion reaction plays a crucial role in the evolution of massive stars and impacts the ignition conditions of Type Ia supernova explosions and superbursts. After decades of research, there remains considerable uncertainty...
The $^{12}$C(ฮฑ, ฮณ)$^{16}$O reaction is a pivotal process in nuclear astrophysics. Due to its extremely low cross section (~10$^{-17}$ barn) within the Gamow window, directly measuring this reaction is highly challenging. An irradiation-resistant $^{12}$C-enriched target is a key technique for the direct measurement of the $^{12}$C(ฮฑ, ฮณ)$^{16}$O reaction. In this work, we developed a...
Impact parameter is crucial in analyzing heavy ion nuclear reactions. As the residual effect of strong interaction force, the magnitude of nuclear force can be ignored in the case of high energy, but it is not suitable for low energy. For low energy, scattering angles in center of mass coordinate can be used to deduce a general impact parameter with a classical mechanics formula. The feature...
The Moon provides a unique environment for investigations of nearby astrophysical events such as supernovae. Lunar samples retain valuable information provided by these nearby astrophysical events, via detectable long-lived "fingerprint" radionuclides such as 60Fe.
In this work, we stepped up the development of an accelerator mass spectrometry (AMS) method for detecting...
The role of nuclear fission in the r-process nucleosynthesis occurring in neutron star mergers is studied. Current theoretical nuclear physics models([1][2][3]) are based on different assumptions on the fission barrier for different fission channels (spontaneous fission, neutron-induced fission, ฮฒ-delayed fission, etc). In this work, the
nuclear reaction network calculation based on a...
The 13C(a,n)16O reaction is the main neutron source for the slow-neutron-capture (s-) process in Asymptotic Giant Branch stars and for the intermediate (i-) process. Direct measurements at astrophysical energies in above-ground laboratories are hindered by the extremely small cross sections and vast cosmic-ray induced background. We performed the first consistent direct measurement in the...
