Over the past decades, the high-precision direct mass measurements of short-lived nuclei have provided important information on a wide range of topics, including the neutron halo structure in very exotic nuclei. In some of the most neutron-rich systems, the last neutrons are extremely weakly bound resulting in their wavefunction extending far outside the nuclear core forming a so-called halo. The motion, size and deformation of the nuclear core was shown to be reflected in the charge radius, while the extent of the diffuse region was linked to the neutron separation energy of the valence, or halo, neutrons. We will present the first direct Penning trap mass measurements of the halo nuclei 6,8He performed at TRIUMF. Using the precise charge radii and neutron separation energies obtained from the new masses, we test various ab-initio nuclear theories and give insight to the interactions at play in the nucleus. Precision experiments with ion traps, such as mass measurements, require low-energy ion beams with minimal energy spread. Therefore, radioactive ions produced at high energies by fragmentation or fission reactions can only be used in precision experiments after they are thermalized in a gas cell. These short-lived nuclei are produced at low-yields so the efficient and quick transport through the buffer gas is critical. We will present the results of the extensive studies of a rapid transport method called “ion surfing” that have been performed at the National Superconducting Cyclotron Laboratory as part of the development of a next-generation beam thermalization system.
Coffee and cookies before the presentation at 3:15 pm, and refreshments after the presentation will both be served in Room 128.