| 摘要 |
PROBLEM TO BE SOLVED: To resolve various problems associated with the use of a hot cathode, by adopting a cold-cathode electron emission source composed of carbon nanotubes as a cathode. SOLUTION: An electron gun unit is comprised of a Wehnelt-cylinder 12, and a cathode 14 is in the Wehnelt 12. The cathode 14 is composed of a cathode base 22 and an emitter 24 that is fixed to the surface of the cathode base 22. The emitter 24 is a member for an electron emission, and made of carbon nanotubes. A target 16 is arranged to face the electron gun unit 10. The electrons, which have been emitted from the emitter 24 due to the effect of an electric field generated by the cathode 14, a lead-out electrode 18, and a target 16, are accelerated at the lead-out electrode 18 and focused at a window 20 of the Wehnelt-cylinder 12, then collide with the surface of the target 16 to generate an X-ray.
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