X-ray fluorescence (XRF) analysis is useful for mapping various atoms in objects. Bremsstrahlung X-rays are selected
using a 3.0 mm-thick aluminum filter, and these rays are absorbed by indium, cerium and gadolinium atoms in objects.
Then XRF is produced from the objects, and photons are detected by a cadmium-telluride detector. The Kα photons are
discriminated using a multichannel analyzer, and the number of photons is counted by a counter card. The objects are
moved and scanned by an x-y stage in conjunction with a two-stage controller, and X-ray images obtained by atomic
mapping are shown on a personal computer monitor. The scan steps of the x and y axes were both 2.5 mm, and the
photon-counting time per mapping point was 0.5 s. We carried out atomic mapping using the X-ray camera, and Kα photons from cerium and gadolinium atoms were produced from cancerous regions in nude mice.
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