Crookes X-ray tube.WMV

Old cold cathode X-ray tube being tested at 25kV X-ray enission being detected with a GM tube. Still long exposure image at end shows the glass glowing.

More on this tube at:
http://www.tuopeek.com/valves.htm

Category:

Science & Technology

Tags:

• Crookes
• xray
• tube

[mountain177]

What gas are those filled with. Xenon ?

[tuopeek1]

@mountain177 Don't think any gas has been added, it's just that the vacuum is not perfect. There is a very small amount of air still present. Some of the remaining gas (air) is absorbed into the gas wall and hardens (improves) the vacuum, a much higher voltage is then required for electrons to travel across the tube.

[Zardoz5280]

No gas is used at all. The tube normally should not glow at all but as already mentioned by tuopeek1, a few traces of air remain.The traces stay by the glass's surface. Then we see that green glow.

They used to hang the tube by 2 chains from rails near the ceiling which sent the power, over 16000 volts, to the tube.

[JonasClark]

Frightening to imagine that many doctors and patients at one time got to see these early cold cathode tubes bare and glowing, up close! Now if only I could find video of one of the upright fluoroscopes in operation!