Patent Number: 050330748
Section: abstract

A new and improved microfocus radiography system incorporating a novel x-ray collimating device for eliminating shadow anomalies caused by secondary radiation from materials within the path of x-rays emitting from an x-ray source. The improved system includes a body defining an opening through which primary radiation may pass from a focal spot x-ray source toward a sample, an x-ray window covering the distal end of the opening, x-ray detection means, and an internal collimator to suppress secondary radiation. The window is penetrable by primary radiation passing through the opening with negligible generation of secondary radiation. The collimator defines an aperture and is disposed along the path of the radiation between said focal spot and said window so as to attenuate any passing primary radiation not directly striking the x-ray window. The collimator is formed from a material having a low vapor pressure at temperatures and pressures at which the system is operated. Portions of said collimator exposed to the passing primary radiation are formed from a material selected to attenuate any passing primary radiation not directly striking the x-ray window, and which generates negligible secondary radiation on exposure to said primary radiation.