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摘要

The electron-emissive element (40) in an X-ray tube is constructed so as to be loop-shaped, so that an electron target which is also loop-shaped can be formed on an anode. Notably for target transmission tubes having an integrated window-anode (10, 12) element, a substantial reduction of the window temperature can thus be achieved. Inter alia because of the lower temperature gradients, the window can be constructed to be thinner; however, its service life is substantially prolonged and the radiation efficiency of the tube is increased.