However, not all the radiation is either completely removed from the beam ortransmitted. Some is deviated within the specimen from its original direction--that is, it is scatteredand is nonimage-forming. This nonimage-forming scattered radiation, if not carefully controlled,will expose the film and thus tend to obscure the useful radiographic image. Scattered radiationand the means for reducing its effects are discussed in detail in "Scattered Radiation". Anotherportion of the energy in the original beam is spent in liberating electrons from the absorber. Theelectrons from the specimen are unimportant radiographically; those from lead screens,discussed in detail in "Radiographic Screens", are very important.
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