Re: NEON- X-RAY bombarder

To be more precise, the penetrating power is a function of the
voltage, and the "brightness" of the x-ray beam is a function
of the current through the tube.

If you have an x-ray tube with a filament, you use the filament
to control the current through the tube. These tubes are a
point source and can be used to produce very SHARP x-ray

On the other hand, something like a light bulb or radio tube
is going to have a more diffuse source, and the resulting x-ray
radiographs will be very fuzzy or blurry unless you increase
the distance of the film/screen from the x-ray source and keep
the distance between the film/screen and object being x-rayed
to a minimum.

With larger source-to-screen distances you have to increase
the exposure times. Exposure time follows an inverse-square
law. For example, if you increase the distance by a factor of
three, then you have to increase the exposure time by a factor
of 3*3=9 to achieve the same level of exposure.

Fr. Tom McGahee

----- Original Message -----
From: Tesla List <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, September 13, 1999 8:33 PM
Subject: Re: NEON- X-RAY bombarder

> Original Poster: "John" <jbowers1-at-jnlk-dot-com>
> Hi Tony, all,
> Voltage and current are the keys to x-ray penetrating power!
> For what it's worth, here's what I personally found at different voltages:
> 20 KV- barely detectable with Geiger counter using thin mica window tube;
> 30 KV- moderately detectable with counter; most x-rays absorbed by a sheet
> of paper;
> 40 KV- easily detectable; penetrate several sheets of paper with ease;
> evidence of very faint fluorescence of x-ray screen in dark;
> 50 KV- easily penetrate paper, sheet metal and very thin lead; x-ray
> showing moderate glowing in dark;
> 60 KV- penetrate stack of paper, thicker metal (die cast to 1/4 inch);
> screen showing brighter glowing;
> above 70 KV- difficult to stop without at least 1/4 inch thick lead;
> easily discerned on screen
> John Bowers