Interaction of 6He with hydrogen isotopes at 26 MeV/n energy

by Mr Bogumił Zalewski (ŚLCJ UW)

Monday 20 May 2024, 11:00 → 12:30 Europe/Warsaw

NO2 Lecture room (IFJ PAN)

Neutron halo nuclei are the most prominent examples of nuclei far away from the stability line. They consist of a compact core and one or two loosely bound neutrons orbiting the core. The lightest halo nucleus is Helium-6 which due to the small number of nucleons is among the most straightforward systems to treat from a theoretical point of view. Experimental studies of such an unstable nucleus are difficult due to the low intensities of produced beams. One of the solutions for this problem is using high cross section process such as elastic scattering. 

This presentation will review the most recent results for the ⁶He+d elastic scattering measurement and ⁶He(d,t)⁵He neutron transfer. The reactions were measured in inverse kinematics, at 26 MeV/n beam energy at ACCULINNA-2. The experiment has been performed in 2018. Both reactions, involving these two weakly bound nuclei, were performed for the first time.

The obtained data set was analysed in the two steps. First, an effective optical model potential was derived from the analysis of ⁶He+p elastic scattering data measured at the same energy. This potential was used to derive optical model potential for d+⁶He by means of single folding (SF) method. Comparison of the optical model calculations involving the SF d+⁶He potential showed good agreement with the experimental data. This result suggests that the effects due to deuteron breakup on the ⁶He+d elastic scattering are small. In the same experiment differential cross section for a ⁶He(d,t)⁵He reaction was obtained. The spectroscopic amplitude for the ⁶He_g.s.=⁵He_g.s.+n configuration was adjusted so that the calculated differential cross section for the transfer reaction reproduced the data points. The spectroscopic factor (SF_5He+n) calculated from the spectroscopic amplitude equals SF_5He+n = 1.36 +0.35 / -0.33 and is smaller than theoretical predictions, but agrees with them within the uncertainties.