I did a post on X-ray scanners a while ago, and it didn’t turn out too well.  I made a technical mistake, and when I fixed it, it was hard to read, so I deleted it.  I won’t try to rewrite it here, but will merely list some web resources relevant to the topic:

• Claim that X-ray doses are very low: (from Cosmic Log).
• Technical description  paper by Kaufman and Carlson: estimated X-ray energies.
• Paper on the angular distribution of X-ray scattering.
• Websites with some relevant technical information: [ 1, 2, 3, 4, 5, 6].