Continuous source of translationally cold dipolar molecules

The Stark interaction of polar molecules with an inhomogeneous electric field is exploited to select slow molecules from a room-temperature reservoir and guide them into an ultrahigh vacuum chamber. A linear electrostatic quadrupole with a curved section selects molecules with small transverse and longitudinal velocities. The source is tested with formaldehyde [Formula Presented] and deuterated ammonia [Formula Presented] With [Formula Presented] a continuous flux is measured of [Formula Presented] and a longitudinal temperature of a few kelvin. The data are compared with the result of a Monte Carlo simulation.