Absorption measurements on a low-pressure inductively coupled argon/mercury discharge for lighting purposes: 2. Electron density and temperature

Typical values for the electron density and temperature in the Philips QL l amp are obtained from the radially resolved measurements of the gas tempera ture profile and the density of the lowest argon metastable state, as prese nted in a previous paper (Jonkers J et al 1997 J. Phys. D: Appl. Phys. 30 1 928-33). The results agree very well with the electron density and temperat ure as found by solving the electron particle and energy balance equations. For increasing argon filling pressure a lower electron temperature and a h igher electron density are found, which are due to an increased residence t ime of the charged particles. It is also shown that in the QL lamp serious depletion of mercury occurs.