The joint work of European target laboratories in the ChETEC-INFRA project is presented, to face the new experimental challenges of nuclear astrophysics. In particular, results are presented on innovative targets of 12,13C, 16O, and 19F that were produced, characterized, and, in some cases, tested under beam irradiation. STAR (Solid Targets for Astrophysics Research) is already acting to increase collaboration among laboratories, to achieve shared protocols for target production, and to offer a characterization service to the entire nuclear astrophysics community.

We report here the results of an experimental study involving the $\ensuremath{\beta}$-delayed proton decay of $^{27}\mathrm{P}$ which was studied with a gas detector, AstroBox2 (AB2), at Cyclotron Institute, Texas A University. Five new low-energy proton groups were detected, individual $\ensuremath{\beta}$-proton ($\ensuremath{\beta}\mathrm{p}$) branching ratios were calculated for the already known and the new proton groups and an improved half-life of $^{27}\mathrm{P}$ was determined. The discovery of this low-energy protons puts under a new light the reaction rate of $^{26m}\mathrm{Al}(\mathrm{p},\ensuremath{\gamma})^{27}\mathrm{Si}$. Additionally, a $^{25}\mathrm{Si}$ exotic beam was used for the energy calibration of the detector. In the data analysis of this isotope implantation was ultimately intended to obtain results in accordance with literature in order to validate our method for the analysis of $^{27}\mathrm{P}$ beam, which was finally achieved. Furthermore, an extended description of the analysis method for experiments with AstroBox2 detector is made.

Gamow-Teller (GT) transitions in an exotic neutron-rich nucleus 11Li have been measured via the 11Li(p, n)11Be reaction at 182 MeV/u in inverse kinematics at RI Beam Factory (RIBF) of RIKEN Nishina Center. The neutron detector array PANDORA and the SAMURAI spectrometer were used to detect recoil neutrons and decay products produced in the (p, n) reaction, respectively. Preliminary results of kinematic correlation of recoil neutrons, corresponding to GT transitions, are presented for several decay channels of 11Be reaction product. Fourteen decay channels with light-particle emission from 11Be excited states, including seven new channels, are identified, in addition to the non-particle-emission channel from 11Be ground or low-lying states.

We report here the results of an experimental study involving the beta-delayed proton decay of 27P which was energy proton groups were detected, individual beta-proton (beta p) branching ratios were calculated for the already known and the new proton groups and an improved half-life of 27P was determined. The discovery of this low-energy protons puts under a new light the reaction rate of 26mAl(p, gamma ) 27Si. Additionally, a 25Si exotic beam was used for the energy calibration of the detector. In the data analysis of this isotope implantation was ultimately intended to obtain results in accordance with literature in order to validate our method for the analysis of 27P beam, which was finally achieved. Furthermore, an extended description of the analysis method for experiments with AstroBox2 detector is made.

12 C + 12 C is the main reaction during core and shell carbon burning in massive stars, however, at temperatures higher than 10 9 K when most of the carbon is depleted and its abundance is lower than 16 O, the 12 C + 16 O fusion can also become relevant. Moreover, 12 C + 16 O reaction can ignite also in the scenario of explosive carbon burning. The astrophysical energy region of interest thus ranges from 3 to 7.2 MeV in the center-of-mass frame. There are various measurements of the cross-section available in the literature, however, they all stop around 4 MeV, making extrapolation necessary at lower energies. To try to solve this uncertainty and corroborate direct measurement the Trojan Horse Method was applied to three-body processes 16 O( 14 N, α 24 Mg) 2 H and 16 O( 14 N, p 27 Al) 2 H to study the 16 O( 12 C, α) 24 Mg and 16 O( 12 C, p) 27 Al reactions.

The carbon-burning process in massive stars mainly occurs via the 12C +12 C. However, at temperatures higher than 109K and considering the increased abundance of 16O produced during the later stages of the heliumburning,the 12C+16O fusion can also become relevant. Moreover, 12C+16O also plays a role in the scenario of explosive carbon burning. Thus, the astrophysical energy region of interest ranges from 3 to 7.2 MeV in the center-of-mass frame. However, the various measurements of the cross-section available in the literature stop around 4 MeV, making extrapolation necessary. To solve this uncertainty and corroborate direct measurement we applied the Trojan Horse Method to three-body processes 16O(14N, α24Mg)2H and 16O(14N, p27Al)2H to study the 12C(16O, α)24Mg and 12C(16O, p)27Al reactions in their entire energy region of astrophysical interest. In this contribution, after briefly describing the method used, the experiment and the preliminary phases of the data analysis will be presented and discussed.

This work describes a silicon tracker system developed for experiments with proton-rich radioactive ion beams at the SAMURAI superconducting spectrometer of RIBF at RIKEN. The system is designed for accurate angular reconstruction and atomic number identification of relativistic heavy ions and protons which are simultaneously produced in reactions motivated by studies of proton capture reactions of interest for nuclear astrophysics. The technical characteristics of the tracking array are described in detail as are its performance in two pilot experiments. The physics justification for such a system is also presented.

Nuclear astrophysics is a field at the intersection of nuclear physics and astrophysics, which seeks to understand the nuclear engines of astronomical objects and the origin of the chemical elements. This white paper summarizes progress and status of the field, the new open questions that have emerged, and the tremendous scientific opportunities that have opened up with major advances in capabilities across an ever growing number of disciplines and subfields that need to be integrated. We take a holistic view of the field discussing the unique challenges and opportunities in nuclear astrophysics in regards to science, diversity, education, and the interdisciplinarity and breadth of the field. Clearly nuclear astrophysics is a dynamic field with a bright future that is entering a new era of discovery opportunities.

The Horia Hulubei National Institute for Research & Development in Physics and Nuclear Engineering (IFIN-HH) operates, among other facilities, a 3 MV Tandetron™ accelerator, built by High Voltage Engineering Europa B.V. Since commissioning in 2012, the 3 MV Tandetron™ has emerged as an important tool to open new horizons in a variety of accelerator-based research fields. In other words, the 3 MV Tandetron™ accelerator has become one of the key facilities in the landscape of Romanian in both basic research and applications. In addition, our laboratory represents an adequate environment for training young scientists and undergraduates since they can develop marketable skills through accelerator-based research, such as data collection/analysis, software development or simulations. After a brief description of the facility, several prominent highlights defining our research capabilities are described. Finally, our ongoing and future upgrades plan is depicted.

In my presentation, I will discuss the use of transfer reactions as an indirect method of determining information important for nuclear astrophysics. Specifically, I will focus on peripheral reactions and their analysis with the Asymptotic Normalization Coefficients (ANC) method. I will present results from related experiments that have been conducted at the Cyclotron Institute, Texas A&M University with focus on the 0ptical Model Parameters obtained and the need for reliable calculations. Additionally, I will describe the im- provements in the measured data that we obtained after upgrading the detection system used.

The 9 C breakup was studied during the SAMURAI29R1 experiment through inclusive and exclusive measurements at energies around 160 AMeV for 9 C, in order to evaluate the astrophysical S 18 factor for the inverse process 8 B(p,γ) 9 C at energies in the region of astrophysical interest.The radiative proton capture on 8 B is important in the hot pp chains, in explosive Hydrogen burning (ppIV and rapI), at temperatures between 0.05 < T 9 < 1K, as possible alternative paths across the A=8 mass gap.Another goal of this experiment was a detailed study of the breakup reaction mechanism.During the experiment the nuclear breakup process was studied using a natural C target with 425 µm thickness and the Coulomb dissociation by using a natural Pb target with 150 µm thickness.The reaction products were tracked simultaneously using a system of position sensitive Si detectors and in total 1024 output channels were read out by using new dual gain preamplifiers (DGP) specially designed for the experiments of the HI-p collaboration.The SAMURAI29R1 experiment was carried out during the SAMURAI 18Oxygen 2018 Spring campaign and it is part of the HI-p collaboration together with another three experiments.Performances of the setup used and first results of the analysis are presented.

The status of a project to measure spin-isospin responses of neutron drip-line nuclei using a new low-energy neutron detector, PANDORA (Particle Analyzer Neutron Detector Of Real-time Acquisition), is reported. The performance of PANDORA was characterized by the He-6(p, n)Li-6 reaction in inverse kinematics at the HIMAC facility in Chiba. Observation of the strong transition to the ground state in Li-6 is discussed. Preliminary results of Li-11(p, n)Be-11 and Be-14(p, n)B-14 experiments in inverse kinematics at RI Beam Factory (RIBF) of RIKEN Nishina Center are also presented including the exotic decay channel of Be-11 -> Li-9 + d. Details of the experimental setup based on PANDORA and the SAMURAI large-acceptance magnetic spectrometer, as well as the combined data-acquisition system are described. The neutron-gamma discrimination capability of PANDORA was evaluated, Figure-of-Merit (FoM) values higher than those found in the literature for similar materials were derived from experimental data.

The spin-isospin responses of the 11 Li drip-line nucleus has been measured. Preliminary results of the 11 Li( p, n ) 11 Be experiment in inverse kinematics at RI Beam Factory (RIBF) of RIKEN Nishina Center are presented including the observation of 1 n , 2 n, t, d , 2 α and 6 He+ α decay channels of 11 Be reaction product. Details of the experimental setup based on PANDORA (Particle Analyzer Neutron Detector Of Real-time Acquisition) low-energy neutron detector and the SAMURAI large-acceptance magnetic spectrometer are described.

We present a facility for direct measurements at low and very low energies typical for nuclear astrophysics (NA). The facility consists of a small and robust tandem accelerator where irradiations are made, and an ultra-low background laboratory located in a salt mine where very low radio-activities can be measured. Both belong to Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH) but are situated 120 km apart. Their performances are shown using a few cases where they are used. We argue that this facility is competitive for the study of nuclear reactions induced by alpha particles and by light ions at energies close or down into the Gamow windows. A good case study was the 13C+12C fusion reaction, where the proton evaporation channel leads to an activity with T1/2 = 15 h, appropriate for samples' transfer to the salt mine. Measurements were done using the thick target method down into the Gamow window for energies from Ecm=2.2 MeV, which is the lowest energy ever reached for this reaction, up to 5.3 MeV, using 13C beams from the 3 MV tandetron. The activation method allowed us to determine a cross section of the order of 100 pb. Reactions induced by alphas were also measured. Proton induced resonant reactions were used to calibrate the accelerator terminal voltage. Some results of the experiemnts characterizing the assembly are sown and discussed.

The9C breakup reaction was investigated in order to obtain information about the inverse reaction: 8B(p,y)9C at astrophysical energies within the NP1412SAMURAI29R1 experiment. The 8B(p,y)9C reaction gives a possible path to the hot pp chain pp-IV at high temperatures and away from it toward a rapid alpha-process rap-I at high temperatures and densities and therefore is important in understanding nucleosynthesis in super-massive hot stars in the early universe, including possible bypass of the 3a process. For this experiment it was proposed to use a combination of nuclear and Coulomb dissociation measurements (on a light target Be or C and on a heavy target Pb, respectively) at energy of 160 A MeV to extract structure information, which will allow to evaluate the radiative proton capture cross section at low energies and from there the reaction rate. The current work is focused on the development of Monte Carlo simulations for Coulomb breakup mechanism of 9C as well as on the Geant4 simulations of the resulting particle trajectories through the experimental setup, including passage of the particles through the magnetic field of the SAMURAI spectrometer.

Using our IFIN-HH facilities: the 3 MV TandetronTM accelerator and the ultra-low background laboratory we were able to study the 4He+64Zn reaction at energies under Coulomb barrier. With these facilities, cross sections of the order of 30 nb were obtained. The thick target yields were determined through measurements of γ-ray yield followed by the decay of 67Ga (T1/2=78.28 h) in two laboratories: microBequerel (the ultra-low background laboratory) and NAG (Nuclear Astrophysics Group) where the gamma rays were detected with HPGe detectors with a relative efficiency of 120% and 100% respectively. In addition, prompt in-beam gamma-rays were detected with an HPGe detector in close proximity as long as the reaction cross section was sufficiently large for those gammas to be extracted from the target hall background. Results of the experiment are shown below.

Elastic scattering reactions have been part of a campaign of studies at the Cyclotron Institute from Texas A&M University for more than 30 years. The studied nuclei ranged from Be-8 to Ne-22. In order to study the astrophysically important Si-26 (through its mirror Mg-26), it was necessary to perform an upgrade of the focal plane detection system. Several scattering reactions on nuclei heavier than A=22 were measured as tests and the preliminary results are presented here.

A MICROMEGAS detection amplifier has been incorporated into the design of the TAMU-MDM focal plane detector with the purpose of improving the energy resolution and thus, the particle identification. Beam tests showed a factor of 2 improvement over the original design, from 10%–12% to 4%–6%, for ions with A≤40 at E/A ∼ 10–20 MeV.

Using our IFIN-HH facilities: the 3 MV Tandetron (TM) accelerator and the ultra-low background laboratory we were able to study the He-4+Zn-64 reaction at energies under Coulomb barrier. With these facilities, cross sections of the order of 30 nb were obtained. The thick target yields were determined through measurements of gamma-ray yield followed by the decay of Ga-67 (T-1/2=78.28 h) in two laboratories: microBequerel (the ultra-low background laboratory) and NAG (Nuclear Astrophysics Group) where the gamma rays were detected with HPGe detectors with a relative efficiency of 120% and 100% respectively. In addition, prompt in-beam gamma-rays were detected with an HPGe detector in close proximity as long as the reaction cross section was sufficiently large for those gammas to be extracted from the target hall background. Results of the experiment are shown below.