Continuous source of translationally cold dipolar molecules

Abstract

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 ( H 2 CO ) and deuterated ammonia ( ND 3 ) . With H 2 CO a continuous flux is measured of ≈ 10 9 / s and a longitudinal temperature of a few kelvin. The data are compared with the result of a Monte Carlo simulation.