Electric-Field-Controlled Cold Dipolar Collisions between Trapped CH3 F Molecules

Abstract

Reaching high densities is a key step toward cold-collision experiments with polyatomic molecules. We use a cryofuge to load up to 2×107 CH3F molecules into a boxlike electric trap, achieving densities up to 107/cm3 at temperatures around 350 mK where the elastic dipolar cross section exceeds 7×10-12 cm2. We measure inelastic rate constants below 4×10-8 cm3/s and control these by tuning a homogeneous electric field that covers a large fraction of the trap volume. Comparison to ab initio calculations gives excellent agreement with dipolar relaxation. Our techniques and findings are generic and immediately relevant for other cold-molecule collision experiments.