X-ray tube with two anode layers on the end window and X-ray fluorescence analyser

摘要

An X-ray tube (100) comprises a housing (101) and a cathode arrangement (102) adapted to emit electrons. A window (103) seals an end of an enclosure in the housing. The window (103) comprises a carrier layer (111) and a layered anode arrangement comprising a second anode layer (113), and a first anode layer (112) between the carrier layer (111) and the second anode layer (113). The material of the second anode layer (113) has a characteristic maximum penetration depth of electrons, and the thickness of the second anode layer (113) is smaller than said characteristic maximum penetration depth. A principal constituent of the second anode layer (113) has a larger atomic ordinal number than a principal constituent of the first anode layer (112).