| 摘要 |
<p>1478320 X-ray tubes MACHLETT LABORATORIES Inc 3 Sept 1974 [4 Sept 1973] 38532/74 Heading H1D An X-ray generator comprises target 38A on X-radiation transparent substrate 36A, source 40A to produce electrons to excite X-radiation from the target surface on substrate 36A and an X-radiation opaque housing 94 (e.g. of Pb) with a window, the substrate at its adjacent target surface being so inclined to the axis that X- rays emitted along the axis are at angles to the normal to the said target surface in the range 80 to 85 degrees. Brehmsstrahlung radiation is attenuated in the axial direction due to the increased path through the inclined substrate. Zone plates of chirpped checkerboard pattern or off-axis Fresnel pattern are mentioned, and attached zone plate 69 may be a Pb containing deposition on a substrate. The conical substrate may be re-entrant (Fig. 2, not shown) and magnets 162, 164, may replace modulation grid 74, and the electrons may scan a raster or spiral thereby smoothing out effects of beam irregularities. The target may be 20-40Á thick and Mo and Ce fluorescent and brehmsstrahlung emissions are discussed w.r.t. Figs. 3, 4 (not shown). Au or W targets are also disclosed. Fig. 1 also includes insulating oil 96, tube base 100 of which substrate 36A forms a part, and glass envelope 98. Diagnostic angiography is discussed utilizing iodine as radiographic dye.</p> |
