Fluorescence Detection and Buffer Gas Cooling of Trapped Mercury Ions in Paul Trap

Hg ions are confined in a hyperboloid ion trap. With the rf discharge ²⁰²Hg isotope lamp, the fluorescence signal of trapped Hg ions is observed. By means of buffer gas cooling, the ionic temperature is reduced. As a result, the trapping time is increased and the signal-to-noise ratio (SNR) of the fluorescent signal is improved. The temperature of ion cloud is estimated by measuring the space charge shift.