In stars the $\rm ^{13}C(\alpha,n)^{16}O$ and $\rm ^{22}Ne(\alpha,n)^{25}Mg$ reactions are the two main sources of neutrons for the so-called slow neutron capture process (s-process), which is the main mechanism for the stellar synthesis of heavy elements. About $\rm ^{13}C(\alpha,n)^{16}O$, in despite of many efforts in measuring its cross section at the lower energies, only high uncertainty...
Storage rings rings provide a new and unique opportunity to resolve long standing by performing nuclear reactions using stored heavy ion beams on an ultra-thin internal gas-jet target. The CRYRING storage ring, part of FAIR phase-0, is unique worldwide by allowing ion beams to be decelerated, cooled and circulated at energies of astrophysical interest. The recently installed and commissioned...
Active Targets are a choice in low-energy nuclear physics when luminosity and high detection efficiency are needed. When combined with a solenoid magnet, their energy dynamic range and particle identification capabilities are greatly enhanced. The Active Target Time Projection Chamber (AT-TPC) of the FRIB is one such detector, a powerful tool to investigate direct and resonant reactions where...
The process that drives nucleosynthesis in x-ray bursts is known to be the rp-process, however questions still remain regarding the mechanism through which breakout from the HCNO cycle into the rp-process occurs. It has been suggested that breakout may occur via the $^{15}$O(α,γ)$^{19}$Ne reaction [1]. Hydrodynamic simulations of x-ray bursts have also shown that the rate of this reaction has...
Even though GW170817 and the associated kilonova from a neutron-star merger were detected in August 2017, the possible sites of r-process elements remain an open question in nuclear astrophysics, including special kinds of core-collapse supernovae (CCSNe). A well-known supernova-produced 60Fe radioisotope has been found in several terrestrial reservoirs proving that material from the ejecta of...
A comprehensive study is carried on the impact of strong magnetic fields on the deconfinement phase transition that is anticipated to occur inside massive neutron stars. The basic but effective Vector-Enhanced Bag model (vBag) is used to analyse quark matter, while the very general density-dependent relativistic mean-field (DD-RMF) model is utilised to study hadronic matter. The matter...
An unprecedented activity has been unleashed in recent years to determine neutrino properties and their interactions. It has been firmly established that neutrinos oscillate and hence are massive particles. Some of the oscillation parameters, such as the neutrino mixing angles, have been measured with some precision, but other properties remain to be determined, such as their masses or the...
For the last 5 years, the Nuclear Astrophysics Group (NAG) at IFIN-HH has been carrying out a campaign to study fusion reactions important in stellar nucleosynthesis, at sub-Coulomb barrier energies. More recently, we have been focusing on reactions between 12C and 16O nuclei, as they define stellar scenarios in various important evolution phases of massive stars.
In the past, this has been...
Reactions induced by alpha particles on stable elements play a relevant role in several scientific fields, from nuclear technologies and nuclear
astrophysics, to dark matter searches and neutrino physics. Accurate data on the neutron yield from the interaction of $\alpha$-particles with nuclei via $(\alpha,n)$ reactions are of particular interest in this context, both due to the inconsistency...
Recent measurements performed at the GSI facilities have experimentally determined the value for the rate of 205Tl bound-state beta decay. This in turn allows to ascertain the nuclear transition matrix element to the first excited state of 205Pb. This information plays a crucial role in a twofold way.
On one hand, the bound-state beta decay of 205Tl could counter balance the 205Pb electron...
The origin of the elemental abundances from iron to uranium can be almost completely assigned to neutron capture reactions by two main stellar scenarios, each being responsible for the production of about one half of the abundances in the mass region A≥56. During explosive nucleosynthesis (occurring in supernovae events and/or neutron star mergers) short-lived and very neutron-rich nuclei are...
Neutron induced reactions on unstable nuclei play a significant role in the nucleosynthesis of the elements in the cosmos. Their interest range from the primordial processes occurred during the Big Bang Nucleosynthesis up to the “stellar cauldrons” where neutron capture reactions build up heavy elements. In the last years, several efforts have been made to investigate the possibility of...
Classical novae are the second most common explosive stellar phenomena in the Universe [1] and, as such, play an important role in the enrichment of the interstellar medium and chemical abundances we observe in the galaxy. One observable, which is key to understanding the processes that drive classical novae, is presolar grains. It is, therefore, important that we are able to characterise the...
Several reactions of light nuclei require a better understanding at the energies relevant for Nuclear As- trophysics. The most relevant one is 12C(α,γ)16O. The reason for this is the importance of the reaction, and the complexity of its cross section at the relevant energies of static helium burning (300 keV) which uncertainty is still undesirably large. As there is no state of natural parity...
