Determination of the 5d6p 3F4-5d2 3F transition probabilities of Ba I

Whether the transitions between 6s5d ³D and 5d6p ³F can be used for laser cooling of barium heavily depends upon the transition probabilities of 5d6p ³F-5d^{2 3}F. Taking the transition 6s5d ³D₃-5d6p ³F⁴ as a scale, the leakage rate of 5d6p ³F₄-5d^{2 3}F was used to evaluate the transition probabilities. 706 nm laser pulses with different durations were applied to a barium atomic beam for 6s5d ³D₃-5d^{2 3}F₄ optical pumping, and the remaining percentages in 6s5d ³D₃ were measured. After exponential fitting, the transition probability of 5d6p ³F₄-5d^{2 3}F_3,4 was determined to be 2.1(4)×10⁴ s^?1, which is in agreement with theoretical calculations using the scaled Thomas-Fermi-Dirac method.