Cold Ions/Warm Neutrals

In addition to the pure calcium Coulomb crystals that we can form by laser cooling and trapping Ca+ ions, we can also load other cations of interest into the trap. These molecular cations are  sympathetically cooled by Coulomb repulsion with the Ca+. The mixed and pure Coulomb crystals can remain cold and trapped for hours at a time, including while exposed to trace amounts of room temperature neutral gas. Any charged products formed as a result of collisions between the trapped ions and neutral gas are also trapped and cooled. We are able to monitor the reactions that occur between the trapped ions and warm neutral gas through fluorescence microscope images and high-resolution time-of-flight mass spectrometry. This combination of techniques form a sensitive and unique environment for physical chemistry and chemical physics.