Abstract
Recently, the magneto-optical trap recoil ion momentum spectroscopy (MOTRIMS) device was successfully fabricated in combination with cold atoms and ultrafast and super intense laser technology. Herein, the MOTRIMS principle was introduced, and the density, temperature, and velocity of the target were analyzed and calibrated using the absorption imaging method and photoionization method. Results indicated that the temperature of the 3D MOT target is (130±30) μK, velocity is (0.1±0.1) m/s, density is approximately 10 9 atom/cm 3, and the densities of the 2D MOT and molasses targets are approximately 10 7 and 10 8 atom/cm 3, respectively. Compared with the hot vapor target, the momentum resolution of the cold atom target in the direction of ion flight improved by approximately 14 times and the mass resolution of the time-of-flight spectroscopy is up to 3000. Moreover, the three-dimensional momentum distribution of Rb + was detected using 800-nm femtosecond laser; an obvious above-threshold ionization phenomenon was observed at a low laser intensity of 10 11 W/cm 2, indicating that Rb + atoms exhibit a large above-threshold ionization cross section. MOTRIMS is a new tool for investigating the strong field quantum micro dynamics of metal atoms owing to its ability to image the momentum distribution of ions in full space.