2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/22352Ultra-cold sodium molecules were produced from an atomic Bose-Einstein condensate by ramping an applied magnetic field across a Feshbach resonance. More than $10^5$ molecules were generated with a conversion efficiency of $\sim$4%. Using laser light resonant with an atomic transition, the remaining atoms could be selectively removed, preventing fast collisional relaxation of the molecules. Time-of-flight analysis of the pure molecular sample yielded an instantaneous phase-space density greater than 20.5 pages, 4 figures (final published version)Statistical Mechanicstext