Simple Cold Cathode X-ray Tube (1900-1905)

tube

This is a very simple bi-anode x-ray tube. Simplicity is good  - it is a hallmark of most early x-ray tubes.
In the photo above, the cupped cathode is positioned on the left side of the spherical bulb. The circular target (anticathode) is in the center of the bulb and oriented at a 45 degree angle to the tube axis. The anode, a flat circular disk, is toward the right.  The cathode and anode are made of aluminum while the target is almost certainly platinum. The tube lacks any type of regulator that would be employed to control the gas pressure inside the tube. Based on its appearance, I would guess that it is quite old, ca. 1900 to 1905.

Unfortunately, there is nothing about the tube that would help identify the manufacturer, the only marking is the number 7853 etched on the glass arm. Tubes of this design were produced by many different manufacturers, and it wasn't that common for the manufacturer's name or logo to be etched on the tube - at least until 1910 or so. Indeed, some manufacturers never put identifying marks on their tubes.

In a 1910 catalog, the Gundelach company indicated that a tube of this type was suitable for medical work. And by medical work, they meant either therapy or diagnosis (imaging) - tubes produced at this time period were rarely specialized. Later Gundelach catalogs stated that such a tube was for use in schools. Either way, if it was to be used for serious work, an x-ray tube needed a regulator.

Size: ca. 8.5" long and 3" diameter.

References:

Ronne, P. and Nielsen, A.B.W. Development of the Ion X-ray Tube. 1986.

X-ray Tubes               Museum Directory

Last updated: 11/07/07
Copyright 1999, Oak Ridge Associated Universities