Trapping Neutral Mercury

Overview

Picture of our Hg magneto-optical trap taken with an UV enhanced EMCCD-Camera

We are setting up a magneto-optical trap for neutral mercury. Mercury has some features that make it interesting in these experiments: (1) It does not have fine- or hyperfine structure in the groundstate. Therefore, no repumping laser is required and trapping should be straight forward. (2) It has two meta-stable states, one of which is the lower level of a cycling transition, i.e. a magneto-optical trap can be set up to also trap mercury on that transition. The lifetimes of these two meta-stable states are fairly long. In fact they are so long that they have never been measured. Calculations show lifetimes in the order of 5 seconds

Goals

The project has the following goals: (1) Measure the lifetimes of the meta-stable
states and evaluate their potential in atomic clocks. (2) Perform photo-associative spectroscopy and determine the long-range potential energy surfaces of mercury dimer. Mercury dimer is important for the test of new methods of ab-initio calculations due to the relativistic effects and correlations present. These measurements will result in important input for these models. (3) Form ultra-cold, i.e. translationally, vibrationally and rotationally cold Hg dimers by pumping Raman transitions in the dimer.