Stopping intense beams of internally cold molecules via centrifugal forces

Cryogenic buffer-gas cooling produces intense beams of internally cold molecules [1]. It offers a versatile source for studying collision dynamics and reaction pathways in the cold regime, and could open new avenues for controlled chemistry, precision spectroscopy, and exploration of fundamental physics. However, an efficient deceleration of these beams still presents a challenge. Here, we demonstrate that intense and continuous beams of electrically guided molecules produced by a cryogenic buffer-gas cell [2] can be brought to a halt by the centrifugal force in a rotating frame [3]. Various molecules (e.g. $CH_3F$ and $CF_3CCH$) are decelerated to below $20m/s$ at a corresponding output intensity of $\sim6\times10^9 mm^{-2}\cdot s^{-1}$. In addition, our RF-resonant depletion detection shows that up to $90\%$ rotational-state purity can be achieved in the so-produced slow molecular beams.\\ \\ $^1$J. D. Weinstein et al., Nature 395, 148 (1998)\\ $^2$L.D. van Buuren et al., Phys. Rev. Lett. 102, 033001 (2009)\\ $^3$S. Chervenkov et al., Phys. Rev. Lett. 112, 013001 (2014)