Abstract: An x-ray tube window cooling assembly (11) for an x-ray tube (18) is provided. The cooling assembly (11) includes an electron collector body (110) coupled to an x-ray tube window (104) and having a first coolant circuit (112). The coolant circuit (112) includes a coolant inlet (114) and a coolant outlet (122). The coolant outlet (122) directs coolant at an x-ray tube window surface (152) to impinge upon and cool the x-ray tube window (104). The coolant is reflected off the reflection surface (146) as to impinge upon and cool the x-ray tube window (104). A method of operating the x-ray tube (18) is also provided.