Ion-acoustic plasma waves in rf-discharge lamps: light-shift stabilization for atomic clocks

In vapor-cell atomic clocks, long-term stability can be significantly influenced by temporal variations in a discharge lamp's output via the light-shift. In order to stabilize the light-shift effect it is necessary to stabilize both the lamp's brightness and its spectral output; and this in turn requires one to stabilize the lamp's temperature and the rf- power driving the lamp. Though the lamp's output intensity can be used as a control parameter for lamp stabilization (e.g. for lamp temperature), another is required. Here, we consider the resonant frequency of ion-acoustic plasma waves as a second control parameter for the stabilization of rf-discharge lamps.