Re: Electric bath? ... X-rays from light bulbs/Tesla Coils
Hi David and all,
Yes, the inverse square law is precisely what I used to use. With it, I
could get a rough idea of the amount of x-radiation the candidate bulb was
producing. And the benefit was that this could be done relatively safely.
I would make a distance/ x-radiation chart and then reverse calculate to
find out the amount of radiation produced, say one foot from the bulb. I'd
still have a pair of binoculars handy for viewing the Geiger meter from
To anyone out there considering experimenting, I cannot stress enough the
importance of time, shielding and distance. Remember that x-rays are like
low energy gamma rays and will easily go through your body. Upon impact
with cellular DNA, they can modify or destroy it. Sometimes the DNA is
modified enough to produce cancer. And it might not take as much exposure
as you think to cause cancer twenty or thirty years down the road. Many of
Roentgen's followers, who continued to experiment with Crookes tubes,
complained of sunburn like symptoms of the hands within six months after
their first exposures. Many of these scientists ended up dying within five
years or having to have their hands amputated. Look at the unfortunate
Harry Cox, who built his own Rhumkorff coil for the purpose of experimenting
with x-ray tubes (I believe this was in the '20's or '30's). He died of
cancer too. Remember, even if the bulb isn't producing x-rays, it might be
emitting ultraviolet radiation of a short enough wavelength to be harmful to
the skin and eyes. If you're unsure about x-ray production, then don't
energize the bulb. I'd certainly avoid using my hand as a capacitive ground
>Original Poster: David Trimmell <davidt-at-pond-dot-net>
>Ionizing radiation, such as x-rays being emitted from a "point source" (the
>bulb), will drop off exponentially with distance, we use the inverse square
>law to calculate dose rate: I1*(D1)^2=I2*(D2)^2 where I1=dose rate at
>distance D1, I2=dose rate at distance D2, D1= first known distance (say at
>12" from source, *x-ray bulb/Tesla coil*), D2=second unknown distance. Use
>basic algebra to solve for I2. This assumes no attenuation or back scatter,
>which will be small in air at any rate.
>The real clue is time/distance/shielding. Reduce your time of exposure,
>increase your distance using the inverse square law, and use shielding.
>If you are unaware of basic radiation safety, then (IMHO) don't play with
>Tesla coils and x-ray producing bulbs. Hopefully I can get my dose rate
>meter fixed and I will test some of the more common bulbs for x-ray
>production using a Tesla coil.
>At 10:54 AM 9/8/1999 , you wrote:
>>Original Poster: "John" <jbowers1-at-jnlk-dot-com>
>>>Original Poster: MikeTesla-at-aol-dot-com
>>>What would be a safe distance if any in a garage for clear incandescent
>>>bulbs, laser tubes, florescent tubes, hydrogen thyratron tubes??
>>I'm not sure there really is any safe distance from x-ray incandescents.
>>However, when I used to experiment, I used distance as my primary shield.
>>would be located roughly 100 yards from my Tesla x-ray device observing
>>results through a small telescope. I'd also have a monitoring Geiger
>>counter with me, with the probe pointed toward the x-ray source at all
>>times. I'd also make sure no one was within the range when the device was
>>energized. I suppose lead shielding could also be used, but I tried it
>>always had arcing problems.
>>Note that the aforementioned applied to my set-up, which was an
>>bulb energized by a small 50 Kv Tesla coil. Other situations may require
>>completely different type of shield.