A jet beam source of cold YbF radicals

Abstract

We have developed a pulsed supersonic beam of slow, cold YbF molecular radicals with an intensity of 1.4 × 109 YbF molecules per steradian per pulse in the X2 Σ+ (v = 0, N = 0) ground state. The translational and rotational temperatures of the beam are equal. The lowest temperature produced was 1.4 K and the slowest centre-of-mass velocity was 290 K. We show that YbF can be made either by ablating Yb metal into a fluorine-bearing carrier gas or by ablating solid precursors into a pure inert carrier gas. This source is suitable for injecting a molecule decelerator and for high-resolution laser-rf-double-resonance studies such as the measurement of the electron electric dipole moment.