Pulsed operation of a ring Stark decelerator

Stark deceleration is a technique that uses time-varying inhomogeneous electric fields to decelerate polar molecules for various molecular beam and trapping experiments. New ring-geometry Stark decelerators with continuously varying voltages offer a method to produce a more intense source of molecules than in the more typically used crossed-pin geometry Stark decelerators. However, this new technique, traveling-wave Stark deceleration, is more experimentally challenging due to the electronic requirements. A third method, pulsed-ring Stark deceleration, uses ring-geometry electrodes with high-voltage pulses to decelerate molecules. The discrete voltages make it easier to implement, and it is more efficient in certain situations due to an increased longitudinal potential gradient. Here, we present an experimental realization of a ring-geometry Stark decelerator using both continuously varying and discrete voltages. Using the pulsed-ring method, we demonstrate a newly accessible low-velocity regime for moderate peak voltages on ring electrodes. This opens up the opportunity to efficiently decelerate various molecular species using a medium length decelerator. A comparison of experimental and simulated results between traveling-wave and pulsed-ring Stark deceleration is presented along with a simple model for determining when each mode is more efficient.