Enhanced electron backscattering in x-ray tubes

摘要

An x-ray tube ( 24 ) includes an anode ( 42 ) defining a target. A cathode assembly ( 40 ) is in operative relationship with the anode to produce x-rays ( 56 ). An evacuated envelope ( 35 ) encloses the anode and cathode. The evacuated envelope includes a metal frame portion ( 39 ). The material comprising the metal frame portion has a backscatter coefficient. An x-ray transmissive window ( 41 ) is joined in a vacuum tight manner to the metal frame portion of the evacuated envelope. The material comprising the x-ray transmissive window has a backscatter coefficient. A backscatter layer ( 90 ) is deposited on the x-ray transmissive window and the metal frame portion of the evacuated envelope around the x-ray transmissive window. The backscatter layer has a backscatter coefficient greater than the backscatter coefficient of both of the window and the metal frame.