X-Rays

[SPBrewer]

1st, Yes, I know of all the dangers involved with experimenting with X-Rays.

I see a number of Videos on YouTube from people creating their own X-Ray machines.  Since Tesla experimented with X-Ray's I guess this can fall under the Steampunk genre.
Does anybody know if the front screen of an old CRT would work as a Fluoroscope?

[Hektor Plasm]

It probably would, but the main problem would be separating it safely from the rest of the tube- the vacuum is very high and the risk of implosion is dangerous. In addition, the coating on the screen itself may degrade once exposed to the air, as well as being easily damaged.
Perhaps the phosphor coating from a fluorescent tube mixed with a cellulose laquer and coated on a glass screen might be better? It's not as toxic as you might imagine, and  is only loosely coated onto the tube.
Certainly easier and less hazardous than the CRT.

HP

[Khem Caigan]

Some of the early screens were a mixture of
phosphor ground into lithographic medium or
shellac and rolled onto a silkscreen. Ground
glass would work just as well, and provide
you with a bit of 'tooth' for the phosphor ink.

And if you use a silkscreen to apply the phosphor
to your ground glass, you can kill two birds with
one stone!

Dim or no light works best for viewing - something
like, say, a 40-watt red bulb for your worklight
would help increase the sensitivity of your eyes
immensely.

Besides the old stand-bys like calcium sulphide
and zinc sulphide, I'd be curious to know just
how well the new strontium aluminates perform
as phosphors.

I agree with Hektor re: imploding CRTs - POP!!!

[Edmund Charles Rutherford]

Sadly, I have no experience with x-ray tubes so I cannot offer any advice on that...but I do enjoy reading about them and seeing what other people have done with them...like this:

1915 X-ray coil powering a Puluj radiometer tube

[SPBrewer]

Was there something in Fluoroscope's to keep them from allowing X-Rays from burning out the eyes of those looking into them?  I'm thinking of putting a video camera in front and viewing from a flatscreen.

[Prof Eumides Blakehurst]

Was there something in Fluoroscope's to keep them from allowing X-Rays from burning out the eyes of those looking into them?

Not that I know of from any of the machines I've seen.

For phosphors, silver sensitised ZnS is pretty multi-purpose, though I doubt it will be any good at the lower end of the energy spectrum, plus the stuff if pretty pricey.

You may want to talk to your local hospital as one of the standard tests of x-ray machines for 'leakage' is to use a test screen of some sort (not too sure of the details), but if you can get hold of some of that film, it would seem to be ideal...

Using the phosphor from fluorescent tubes is not a good idea as it will be contaminated with mercury - but if you can find a supplier of the original phosphor before it gets made into tubes you will be fine.

To dismantle a CRT - in Australia at least - there should be a small glass tube somewhere on the CRT with a fine, melted off end. You just put a damp cloth over the tube and use a pair of pliers to break the end of the little tube. It's meant to let air into the main CRT in a controlled way. That is an Aussie safety standard so I don't know where it also applies elsewhere in the world.

[Hektor Plasm]

To avoid any possible contact with mercury, the large bulbous lamps that have an outer globe coated internally with the phosphor and a central high-pressure mercury arc tube could be used, but you would have to get them from some industrial source. The big ones are quite impressive.

HP

[Mr. Consciousflesh]

Been there , done that , still have some hair on my head     The front part of the CRT tube is made from the lead glass , so you can't use it without cutting the whole back of the tube  which is hard , even using diamond saw blades.  The cheapest X-ray screen can be made from a glow in the dark "emergency exit" sign , with all the green markings removed. It works fairly well , except for its very long luminescence time . If you want to build something better , you should look on the ebay for a used X-ray film cassette containing so called "intensifying screen" . 

[Khem Caigan]

The cheapest X-Ray screen can be made from a glow in the dark "emergency exit" sign, with all the green markings removed. It works fairly well, except for its very long luminescence time.

It is possible to reduce the luminescence threshold by
spraying some aluminum paint on top of the phosphor
layer, or even by applying a layer of aluminum foil - only
the 'hotter' particles will pass through to activate the
luminescent coating.

[Mr. Boltneck]

Do any of the normal UV-fluorescent compounds also fluoresce under X-rays? It seems as if they should. If so, then a sheet of leaded glass coated on the back (the side toward the tube) with something like 1-Shot enamel might be a useful screen. I mention leaded glass for the sake of not having the optimum viewing angle become the maximum exposure angle. Arranging a nice big mirror so that you are seeing the screen in the mirror, whilst staying out of the beam-line, might be another useful idea—Mythbusters uses a similar technique to film firearms from anywhere near the axis of the barrel, as I understand it.

[Khem Caigan]

Do any of the normal UV-fluorescent compounds also fluoresce under X-Rays?

Yes, they all do. And applying any of them to the
backside of a sheet of leaded glass is certainly
a sound approach.

[SPBrewer]

Khem Caigan,
   It sounds like you have had lots of experience with X-Rays.  Do you have professional experience?

[Khem Caigan]

Khem Caigan,
   It sounds like you have had lots of experience with X-Rays.  Do you have professional experience?

I am not an X-Ray technician by trade;
just another avid amateur experimenter
with some forty years of experience of
tinkering with such-like gizmos.

When I was coming up, we had all sorts
of anthologies available to us that were
chock-a-block with interesting as well as
relatively dangerous experiments, not to
mention The Amateur Scientist section
toward the rear of Scientific American
magazine.

I also recommend spending some time in a
darkened room - say, half-an-hour or so -
and simply observing any screen that you
prepare without exposing it to any isotopes
or emitters whatsoever.

It can be quite an 'eye-opener' to the energetic
nature of the ambient background that you live
in from day-to-day.

[SPBrewer]

Hmmm....Maybe Fluoroscopic Goggles would be interesting. 

[Siliconous Skumins]

I read about this some days ago, but I'm always hesitant to post information about how to give yourself a dose of ionising radiation....

However this thread is still progressing, so here is an interesting link you may find usefull:

Home Built Portable X-Ray machine

http://teravolt.org/x-ray-machine/


Just remember, this project is a good way to get a Darwin award!   

SS

[Mr. Boltneck]

You could make a sticky-tape x-ray emitter: http://www.nature.com/news/2008/012345/full/news.2008.1185.html

[SPBrewer]

You could make a sticky-tape x-ray emitter: http://www.nature.com/news/2008/012345/full/news.2008.1185.html

This section of the article caught my attention:

"This kind of energy release — known as triboluminescence and seen in the form of light — occurs whenever a solid (often a crystal) is crushed, rubbed or scratched. It is a long-known, if somewhat mysterious, phenomenon, seen by Francis Bacon in 1605. He noticed that scratching a lump of sugar caused it to give off light."

Isn't this the piezoelectric effect?  If so, wouldn't a piezoelectric cigarette lighter also produce X-Rays?  Hmm...Back to the "Queen Victoria's Revenge"'s work shop.

[Siliconous Skumins]

Isn't this the piezoelectric effect?  If so, wouldn't a piezoelectric cigarette lighter also produce X-Rays?  Hmm...Back to the "Queen Victoria's Revenge"'s work shop.

Yes-ish, and NO!...  They are both effects due to electrons, however the difference is that triboluminescence is caused by the breaking of chemical bonds and the subsequent recombination of the charges (an Electron changing to a lower energy state will lose energy by the emission of a photon of light - the higher the energy level shift, the greater the excitation of the photon, thus frequency / colour).  The piezoelectric effect is due to accumulation of charge in a material due to a response to mechanical stress. The piezoelectric effect is a reversible process, materials that produce electricity to mechanical stress, will produce mechanical changes in responce to an applied electrical charge. Triboluminescence is not reversable, application of light will not produce electricity.

However there is nothing preventing you from using the piezoelectric effect as the voltage source to produce X-rays - though they would be short pulses and probably only able to produe 'soft' X-rays (which would be safer anyway). You could probably reuse an old vacuum tube of suitable internal layout as an X-ray tube (if the voltage is high enough, it should work). There is also a type of piezoelectric voltage amplifier that is used for CCFL backlights in some devices, it should be possible to use these as a suitable high voltage source (should be good for around a couple of KV - depending on the strike voltage of the CCFL that they were intended for...). This should be enough to drive a vacuum tube to produce X-rays (can happen in normal use in some guitar amps, so....). 

SS

[SPBrewer]

I've purchased two 11' x 17' OPTEX X-Ray Intensifying Screens from Ferdy's.  Now I will need to get my hands on some sheets of lead. (I should have thought of that earlier.  Oh well, I saw a copy of "The Boy Electrician" while I was last at Ferdy's, so I'll go back for that and check on the Lead then.
I've got a good feeling about this project. 
Does that Darwin Award pay as much as the Nobel Prize?

[von Corax]

Does that Darwin Award pay as much as the Nobel Prize?

Not sure what it pays, but I do know that no past winner has ever complained.

[SPBrewer]

I need help.  Since I have no experience in X-Rays and have recently purchased what I was told to be 11' x 17' OPTEX X-Ray Intensifying Screens.  Here is what I got:

http://www.flickr.com/photos/brewers_2150/6698597667/#
http://www.flickr.com/photos/brewers_2150/6698595907/#
http://www.flickr.com/photos/brewers_2150/6698593427/#

Is the translucent green plastic sheet the "Intensifying Screen"?
Is there lead behind the brown, used to stop X-Rays?

[Mr. Consciousflesh]

   There should be a white piece of thin plastic glued to a something resembling a sponge . It usually has a number stamped on it. This would be your intensifying screen . The brown part is the front of the cassette , usually made from thin aluminium . There is no X-ray shielding in the cassette .
   The IR screens work with x-ray energies as low as 20-25 keV . With them you can start your experiments with soft x-rays , which are easier to shield ( the lead flashing foil would suffice ) . This will reduce your chances of getting the Darwin Award , or at least delay getting it until I got mine
   Please , play it safe . The high voltage power supply for the x-ray tube will kill you instantly , the x-ray exposure could cause a slow and painful death .  Do not trust your own equipment , there could be a leakage in your shielding or a breakdown in the insulation . Also some crystalline structures produce a significant x-ray reflection , so you don't need to be in front of the lamp to become exposed to the radiation . It is best to do your experiments remotely from a safe distance in a place in which you won't endanger other people.

[SPBrewer]

   There should be a white piece of thin plastic glued to a something resembling a sponge .

Like this?
http://www.flickr.com/photos/brewers_2150/6705323129/#

[SPBrewer]

How much glass is required to stop x-rays?  See:

X-Rays from a Vacuum Tube and Induction Coil

Also, there was another site that mentioned glass used to stop x-rays, but absent minded me forgot to bookmark it. 

[Khem Caigan]

Leaded glass works much better at stopping the
more energetic particles than ordinary glass :

Leaded Glass & Leaded Acrylic
@Nuclead
http://tinyurl.com/7vj7x6e

Leaded Safety Glasses
@Universal Medical Inc.
http://tinyurl.com/6ohtsrh

The vendor above even offers two different
styles of goggles - see:

RG-RKG Vented Radiation Goggle Black - Plain
http://tinyurl.com/7s2fd7c

Silicone Radiation Goggle Gray
http://tinyurl.com/7axvtof

I recollect being quite astonished, when I first
began studying such things, at the amount of
lead that one could incorporate in glass - and
which in no way interfered with its transparency.