Pregnant Jackson X-ray Tube (ca. 1896-1900)
This is a somewhat unusual modification of a Jackson tube. What makes it unusual is the fact that the bulb is offset from the long axis of the tube. It almost looks as if the tube were pregnant.
Perhaps the idea was to increase the distance between the target and that portion of the bulb wall towards which the x-rays were directed. This would minimize heating of the glass, at least to some extent. The small tube illustrated in the advertisement at the bottom of the page shows a somewhat similar design.
The cup-shaped aluminum cathode is located in the glass arm just above (as seen in the photo) the point where the arm connects to the top of the spherical bulb. The anode, which serves at the target, is oriented at 45 degrees to the tube axis. It is almost certainly made of platinum.
Unfortunately there are no visible markings that might assist identify the manufacturer.
Size: ca. 11" long and 2.5" diameter.
Copyright 1999, Oak Ridge Associated Universities