Development of a Laser Optically Pumped Polarized Target for Use in Heavy-Ion Physics

摘要

Important micro- and macroscopic details of heavy-ion reactions may be explicitly determined when nuclear spin aligned (polarized) targets are used. For deformed nuclei, the orientation of the symmetry axis of the nuclear density distribution is determined by the nuclear spin orientation. Polarized targets would thus allow experiments to be performed as a function of the orientation of the symmetry axis of the nuclear density distribution. A polarized target of exp 151 exp 153 Eu is being developed at Oak Ridge and is based on laser depopulation optical pumping. A spatially defined target is provided by a supersonic gas jet and consists of Eu atoms seeded into an inert carrier gas. Detailed time-dependent optical-pumping calculations predict approx. = 90% nuclear spin polarization in a Eu target with an expected thickness in excess of 10 exp 15 atoms/cm exp 2 . We present some of the effects that will be observable in heavy-ion reactions when deformed polarized targets are used. (ERA citation 07:051254)