Homemade X-Rays From A Vacuum Tube

Homemade X-Rays From A Vacuum Tube

In the electromagnetic spectrum, X-rays are between ultraviolet and gamma waves, but there is some overlap between the x-rays and gamma waves. Simply speaking, the difference between X-rays and gamma rays is that: 

Gamma radiation is produced by nuclear decay of radioactive atoms.

X-rays are produced by electrons banging into metal.

Except for their source, there is basically no defined difference between the two. They're just photons, like all electromagnetic phenomena. Photons have no mass and no charge. They are light itself. I've played with gamma radiation already using my mineral collection. To experiment with x-rays I had to make them myself. So I did! 

How did I do it? Easy! 

I found an old vacuum tube with a metal cap on top.

I took a multimeter set to Ohms and touched the probes to each pin. The two pins that gave any reading were the heater pins.

I took the output wires from my high voltage source and connected one to the metal cap and the other to one of the heater pins.

Turn on the power to over 20, 000 volts and a purple glow inside the tube made my Geiger counter go wild! 

My power source was a $9 3.6v-6v to 400, 000 volt boost step up power module high voltage generator from Amazon. I could have fed it with two AA batteries, but i just used the Elenco power supply I built to give it 6v DC input.

The tube was $1 at a local antique shop. I have a bunch and only one produced a lot of x-rays. The first one in the video was actually the only other one to produce x_rays, although rather weakly.

Instead of a power source to power the step-up boost transformer, two AA batteries would work fine. I used it to give 0-6 volts DC input into the boost transformer at up to 1 amp. Then I used the 3 amp outputs and the purple glow inside the vacuum tube grew intense, but so did the internal sparks and noise so I don't recommend it.

Here is the setup:

Here's the spark gap without the vacuum tube in between the wires.

I have a photographic darkroom, so I'll eventually get around to x-raying things on top of film plates and developing them. 

About the metal cap at the top of my tubes:

The metal top cap connects to one of the electrodes, the other electrodes being connected to the tube’s base pins. There are a few uses for the metal top cap seen on some vacuum tubes: sometimes it’s used as the anode, which means it’s more robust and can handle higher voltage. They run the highest voltage through the metal cap so it’s isolated this way. 

They also do the exact opposite: sometimes a very low signal was sent through the metal cap for control grids. 

So, either the metal cap can be the HIGHEST most dangerous voltage-or the LOWEST safest voltage that you may actually need to test. 

It’s a real gamble. You might fry your meter or even get electrocuted. For my uses I ASSUME that the metal cap is the anode and blast it with high voltage to produce x-rays. I touch NOTHING and if the tube blows I don’t really care. In my case my meter makes no physical contact since it’s a Geiger counter. Back in the “good old days” you could tap your finger on the metal grid control cap and hear it on sound equipment…of course if that control cap turned out to be hooked to the anode you wouldn’t have a finger left. ZAP!

Above is a video of my newest tube: the infamous 2x2 which gives off massive amounts of x-rays. It doesn't seem this matter which pin I fed the high voltage to, the result was lots of x-rays.