A near-resonant all-optical Li atom trap for few-body experiments

Momentum-resolved scattering experiments with laser cooled targets have been performed with MOTRIMS (Magneto-Optical Trap - Recoil Ion Momentum Spectroscopy) for the last two decades. However, the inhomogeneous magnetic field in a MOT impairs the electron momentum measurement limiting MOTRIMS to ion detection only. The development of MOTReMi (Magneto-Optical Trap Reaction Microscope) made it possible to achieve coincident e^--ion detection by pulsing the inhomogeneous magnetic field. Nevertheless, using this approach comes at the cost of measurement efficiency and a loss of target density. Here we report on the first realization of a near-resonant all-optical ⁶Li atom trap which does not require an inhomogeneous magnetic field. The temperature and density of the atom cloud were found to be approximately 2 mK and 10⁹ atoms/cm³ respectively, making it ideal for momentum-resolved e^--ion coincidence experiments. Moreover, this technique only requires minor adjustments to the polarization and geometry of the laser beams, with respect to a conventional MOT configuration, making it applicable in existing MOTRIMS experiments.

NSF Grant No. 1554776 & University of Missouri Research Board.