Chirped magneto-optical trap of molybdenum

Abstract

We have directly loaded a cryogenic beam of molybdenum atoms into a magneto-optical trap. By chirping the detuning of the trapping lasers, we were able to enhance the number of atoms loaded into the trap by more than a factor of two. We optimize the trapped samples for atom number, temperature, and lifetime by varying the laser-cooling parameters. The laser-cooled molybdenum atoms are subsequently transferred to a magnetic trap where we achieve vacuum-limited lifetimes of 100\,ms. Comparison of magneto-optical trap and magnetic trap lifetimes allow us to extract partial decay rates of the $\text{z}\,^7\text{P}^\text{o}_4\rightarrow\text{a}\,^5\text{D}_4$ and $\text{z}\,^7\text{P}^\text{o}_4\rightarrow\text{a}\,^5\text{D}_3$ transitions. We also provide measurements of the isotope shifts for the $\text{a}\,^7\text{S}_3\rightarrow \text{z}\,^7\text{P}^\text{o}_4$ transition with up to four times better precision than previously reported. Finally, we discuss the prospect of applying the chriped magneto-optical trap to produce laser-cooled samples of MgF.