First proof-of-principle experiment with the post-accelerated isotope separator on-line beam at BRIF: measurement of the angular distribution of ^23 Na + ^40 Ca elastic scattering

The reaction dynamics of exotic nuclei near the drip line is one of the main research topics of current interest. Elastic scattering is a useful probe for investigating the size and surface diffuseness of exotic nuclei. The development of rare isotope accelerators offers opportunities for such studies. To date, many relevant measurements have been performed at accelerators using the projectile fragmentation technique, while the measurements at accelerators using isotope separator on-line (ISOL) systems are still quite scarce. In this work, we present the first proof-of-principle experiment with a post-accelerated ISOL beam at the Beijing Radioactive Ion Beam Facility (BRIF) by measuring the angular distribution of elastic scattering for the stable nucleus ^23 Na from the doubly magic nucleus ^40 Ca at energies above the Coulomb barrier. The angular distribution measured by a silicon strip detector array in a scattering chamber using the ISOL beam at BRIF is in good agreement with that measured by the high-precision Q3D magnetic spectrograph using the non-ISOL beam at nearly the same energy. This work provides useful background for making BRIF a powerful tool for the investigation of the reaction dynamics of exotic nuclei.