We analyze the case of x-ray absorption imaging in which the x-ray source is broadband and the detector does not provide spectral resolution. Our particular interest is in the observation of the Hg vapor distribution in high-intensity discharge lamps. When absorption by the target is small, the problem can be accurately couched in terms of a mean absorption cross-section averaged over the x-ray spectral distribution and weighted by the energy-dependent response of the detector. We test the method against a Au foil standard and then apply it to the observation of Hg vapor. The mean absorption cross-section for Hg is obtained for a Ag-anode x-ray tube at accelerating voltages of 25 kV, 30 kV, and 35 kV, and for high-intensity discharges in fused silica or poly-crystalline alumina arc tubes.
Citation: Journal of Physics D-Applied Physics
Pub Type: Journals
Hg, imaging, lighting, plasma, x-ray