Subkelvin Cooling NO Molecules via "Billiard-like" Collisions with Argon

Abstract

We report the cooling of nitric oxide using a single collision between an argon atom and a molecule of NO. We have produced significant numbers (10 8 to 10 9 molecules per cubic centimeter per quantum state) of translationally cold NO molecules in a specific quantum state with an upper-limit root mean square laboratory velocity of 15 plus or minus 1 meters per second, corresponding to a 406 plus or minus 23 millikelvin upper limit of temperature, in a crossed molecular beam apparatus. The technique, which relies on a kinematic collapse of the velocity distributions of the molecular beams for the scattering events that produce cold molecules, is general and independent of the energy of the colliding partner.