Merging Two Molecular Beams of ND${}_3$ up to the Liouville Limit

In low-energy collisions between two dipolar molecules, the long-range dipole-dipole interaction plays an important role in the scattering dynamics. Merged beam configurations offer the lowest collision energies achievable, but they generally can not be applied to most dipole-dipole systems as the electrodes used to merge one beam would deflect the other. This paper covers the design and implementation of a merged electrostatic guide whose geometry was numerically optimized for ND${}_3$-ND${}_3$ and ND${}_3$-NH${}_3$ collisions. This device guides both beams simultaneously and makes them converge up to an effective collision angle of 2${}^{\circ }$, yielding the optimal compromise between spatial overlap and the lowest possible collision energy. We present preliminary data for inelastic ND${}_3$-ND${}_3$ collisions.