New mass measurements at the neutron drip-line
Résumé
A new SPEG mass measurement experiment has been performed to determine masses closer to the neutron drip-line in the mass region A $\sim$ 10-50. The precision of 37 masses has been improved and 8 masses were measured for the first time. The region covered was motivated by the study of shell structure and of shape coexistence in the region of closed shells N = 20 and N = 28. The evolution of the two neutron separation energies and the shell correction energy have been studied as a function of the neutron number. The results thus obtained provide a means of identifying, in exotic nuclei, new nuclear structure effects that are well illustrated by the changes of the conventional magic structure.
