Magnetoelectrostatic trapping of neutral OH molecules

Advances in cold molecule production promise to profoundly impact research on precision measurement, quantum information, and controlled chemistry. To this end, we employ a Stark decelerator to remove 99.5{\%} of the center-of-mass kinetic energy of a supersonic beam of ground-state OH molecules. We subsequently trap a 70 mK sample of the decelerated molecules at a density of $>$10$^{5}$ cm$^{-3}$ within a magnetic quadrupole whose center lies $\sim $1cm from the decelerator exit. Our magnetoelectrostatic trap (MET) design allows for the addition of an electric field of variable magnitude to the trapped sample to facilitate polar-molecule collision studies. We report progress toward observation of cold collisions between samples of polar molecules.