2025/01/09 by Sun, Qi, Dai, Jinyu, Koots, Rian +4 · 1 citation
#Atomic Physics (physics.atom-ph) #Chemical Physics (physics.chem-ph) #FOS: Physical sciences #Quantum Gases (cond-mat.quant-gas)
paper · doi:10.48550/arxiv.2501.05613
Cryogenic buffer gas sources are ubiquitous for producing cold, collimated molecular beams for quantum science, chemistry, and precision measurements. The molecules are typically produced by laser ablating a metal target in the presence of a donor gas, where the radical of interest emerges among the reaction products due to a barrier-free process or under thermal or optical excitation. High-barrier reactions, such as between calcium and molecular hydrogen, should be precluded. Here, we study chemical reactions between Ca and three hydrogen isotopologues H2, D2, and HD in a cryogenic cell with helium buffer gas. Remarkably, we observe that H2 can serve as both a reactant and a buffer gas, far outperforming D2 and HD. Our results demonstrate a robust method for generating cold beams of alkaline-earth-metal hydrides for laser cooling and trapping. The observations are complemented by a reaction model, yielding qualitative agreement with the experiment.