| 摘要 |
An x-ray source for use in computerized tomographic applications focuses an electron beam (14) on an arcuate anode ring (15) to produce an x-ray beam which passes through a planar slice of the subject (20) under study. Because it is very difficult to focus and to bend an electron beam having a cross section with other than cylindrical symmetry, and because it is highly desirable that the cross section of the electron beam have a rectangular cross section as it impinges upon the anode (15), an electro-magnetic means (40) is disposed adjacent the electron beam path between the anode and the beam bending coils to oscillatorily deflect the beam so that it effectively exhibits a substantially rectangular cross section, the long dimension of the rectangle always pointing toward the system axis. This configuration permits either a more intense x-ray source or, alternately, an x-ray source with a smaller projected spot size. |
