Progress towards a MOT for CaF

We report on progress toward a magneto-optical trap (MOT) of CaF molecules. While following the same essential approach as that used to laser cool SrF and YO [1,2], we are developing direct MOT loading from a 2-stage cryogenic buffer gas beam (CBGB) source [3]. This source has a lower forward velocity compared to the hydrodynamic CBGB source that was employed with SrF and YO. We report the creation of the first CBGB loaded MOTs, without the use of a Zeeman slower, for Ho, Yb, Er, and Tm [4]. The slower initial beam velocity of the two-stage CBGB should aid in MOT loading of molecules, which have inherently low MOT capture velocities ($\sim 10$\,m/s). We plan to implement an AC-MOT for CaF, and report on theoretical studies and experimental progress toward that goal.\\[4pt] [1] E.~F.~Shuman, et al., Nature 467, 820 (2010)\\[0pt] [2] M.~T.~Hummon, et al., Phys. Rev. Lett. 110, 143001 (2013)\\[0pt] [3] N.~R.~Hutzler, et al., Chem. Rev. 112, 4803 (2012)\\[0pt] [4] B.~Hemmerling, et al., arXiv:1310.3239