Date/Time: Thu Sep 11 2025 at 13:30<br/><br/>Location: MOB Auditorium<br/><br/>Speaker: Michele Sguazzin ( IJCLab (CNRS/Université Paris Saclay), Orsay)<br/><br/>Title: Surrogate astrophysics reactions at heavy ion storage rings (NECTAR) and Nuclear decay in highly charged ions (HINA)<br/><br/>Abstract: Neutron-induced reaction cross sections of unstable nuclei are essential for understanding the synthesis of heavy elements in stars and for applications in nuclear technology. However, their direct measurement is complicated due to the radioactivity of the targets involved. In the frame of the NECTAR (Nuclear rEaCTions At storage Rings) project, we circumvent this problem by combining the surrogate reaction method in inverse kinematics with the unique possibilities of storage rings. Thanks to this new technique it is possible to measure the probabilities for competing decay channels as a function of the compound-nucleus excitation energy. These probabilities are then used to constrain the associated level densities, gamma-ray strength functions and fission barriers. Two successful NECTAR experiments were run at the Experimental Storage Ring (ESR) of the GSI/FAIR facility. I will describe the first experiment, carried out in June 2022, which was the first successful surrogate-reaction experiment at the ESR. I will present the detail of the experimental set-up, the data analysis and results.
In the second part of my talk, I will introduce: HINA (Highly charged Ions for Nuclear physics and Astrophysics). This new project, recently awarded with a French ANR grant, will study the decay of highly charged ions to clarify their impact on the nucleosynthesis of elements. HINA will use an ion trap as a cost-effective alternative to a storage ring. The trap to be built is an Electron Beam Ion Trap (EBIT) similar to the HC-EBIT, available at the MPIK of Heidelberg in Germany, for future use at GANIL?s DESIR facility. HINA will first focus on the orbital electron capture (EC) but EBITs offer exclusive possibilities in terms of multidisciplinary research that can be carried out in parallel. Exotic decay processes of HCIs, such as bound-state ß-decay, can be investigated, while studies on the hyperfine structure are a powerful tool for additional spectroscopy.
This seminar is supported by the CNRS-TRIUMF International Research Laboratory NPAT<br/><br/>.<br/><br/>______________________________<br/><br/>Detailed information available can be found at <a href='https://www.triumf.ca/research-program/lectures-conferences/upcoming-seminars-lectures'>https://www.triumf.ca/research-program/lectures-conferences/upcoming-seminars-lectures</a> <br/><br/>