The extremely neutron-rich nucleus ${}^{19}\mathrm{C}$ has been studied by Coulomb dissociation into ${}^{18}\mathrm{C}+n$ at $67A\mathrm{MeV}$. A large $E1\mathrm{}$ strength of $0.71\pm 0.07e^2\mathrm{fm}{}^2$ has been observed at low excitation energies. An analysis of the angular distribution of ${}^{18}\mathrm{C}+n$ center of mass has led to a determination of the neutron separation energy of ${}^{19}\mathrm{C}$ to be $530\pm 130\mathrm{keV}$. The $E1\mathrm{}$ strength distribution can be well reproduced for a ${}^{19}\mathrm{C}$ ground state structure with a dominant $s$-wave valence neutron, providing a consistent picture of the neutron halo structure of ${}^{19}\mathrm{C}$.

Absolute cross sections for isotopically identified products formed in multinucleon transfer in the ${}^{136}\mathrm{Xe}+{}^{198}\mathrm{Pt}$ system at $\sim 8\mathrm{MeV}/\mathrm{nucleon}$ are reported. The isotopic distributions obtained using a large acceptance spectrometer demonstrated the production of the “hard-to-reach” neutron-rich isotopes for $Z<78$ around the $N=126$ shell closure far from stability. The main contribution to the formation of these exotic nuclei is shown to arise in collisions with a small kinetic energy dissipation. The present experimental finding corroborates for the first time recent predictions that multinucleon transfer reactions would be the optimum method to populate and characterize neutron-rich isotopes around $N=126$ which are crucial for understanding both astrophysically relevant processes and the evolution of “magic” numbers far from stability.

The masses of ${}^{246}\mathrm{Es}$, ${}^{251}\mathrm{Fm}$, and the transfermium nuclei ${}^{249-252}\mathrm{Md}$ and ${}^{254}\mathrm{No}$, produced by hot- and cold-fusion reactions, in the vicinity of the deformed $N=152$ neutron shell closure, have been directly measured using a multireflection time-of-flight mass spectrograph. The masses of ${}^{246}\mathrm{Es}$ and ${}^{249,250,252}\mathrm{Md}$ were measured for the first time. Using the masses of ${}^{249,250}\mathrm{Md}$ as anchor points for $\alpha$ decay chains, the masses of heavier nuclei, up to ${}^{261}\mathrm{Bh}$ and ${}^{266}\mathrm{Mt}$, were determined. These new masses were compared with theoretical global mass models and demonstrated to be in good agreement with macroscopic-microscopic models in this region. The empirical shell gap parameter ${\delta }_{2n}$ derived from three isotopic masses was updated with the new masses and corroborates the existence of the deformed $N=152$ neutron shell closure for Md and Lr.

The new isotope ${}^{241}\mathrm{U}$ was synthesized and systematic atomic mass measurements of nineteen neutron-rich Pa-Pu isotopes were performed in the multinucleon transfer reactions of the ${}^{238}\mathrm{U}+{}^{198}\mathrm{Pt}$ system at the KISS facility. The present experimental results demonstrate the crucial role of the multinucleon transfer reactions for accessing unexplored neutron-rich actinide isotopes toward the $N=152$ shell gap in this region of nuclides.