Direct Observation of De-Mixing in a Ceramic Metal-Halide Lamp Using High Energy X-Ray Induced Fluorescence
John J. Curry, H G. Adler, W -. Lee, S Shastri
Number densities of the elemental constituents in a ceramic metal-halide high intensity discharge lamp have been obtained with x-ray induced fluorescence. Hg, Dy, Cs, and I have been examined as a function of radial position in the midplane of a Hg lamp dosed with DyI3 and CsI. The elemental densities directly yield elemental ratios with no intervening assumptions about the local temperature or chemical partition functions. The elemental ratios clearly show de-mixing of the metal additives. Dy:Hg and Cs:Hg ratios both exhibit a distinct region of depletion centered on the axis of the discharge. This depletion is attributed to ambipolar transport of positive ions out of the core.
, Adler, H.
, Lee, W.
and Shastri, S.
Direct Observation of De-Mixing in a Ceramic Metal-Halide Lamp Using High Energy X-Ray Induced Fluorescence, Applied Physics Letters
(Accessed February 22, 2024)