  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
in a technique called traveling-wave Stark deceleration. However, this type of
deceleration is more experimentally challenging than the more typically used
crossed-pin geometry decelerators with pulsed voltages. Here, we present an
experimental realization of a ring-geometry Stark decelerator using either
continuously varying or discrete voltages. Pulsed-ring Stark deceleration using
discrete voltages is easier to implement and, under certain circumstances, is
more efficient than traveling-wave Stark deceleration. 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.
