Chemical production of CaH in a CBGB source and progress toward a 3D MOT

Direct laser-cooled calcium monohydride (CaH) molecules are a promising platform for the creation of ultracold atomic hydrogen. However, the molecular yield of CaH in cryogenic buffer gas beam (CBGB) sources has so far been 1-2 orders of magnitude lower than for other laser coolable molecules such as CaF and CaOH. Here we report our study of the CaH chemical production in a CBGB source with different hydrogen isotopologues. We show that H₂ outperforms deuterated isotopologues and can serve as both a reactant and a buffer gas coolant. The results are in good agreement with a reaction model that we have developed. We further show initial laser slowing of CaH, with molecules slowed to below 50 m/s. Finally, we show our progress toward a 3D radio-frequency MOT of CaH, which should be possible with the demonstrated enhanced yield of chemical production and efficient laser slowing.