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UnintentionalChaos
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You will need actual black and white film for this. I have done some B&W work before and it shouldn't be too hard. If you try to develop color
film in B&W chemicals you got nothing...I've seen someone try...See if you can get Kodak Tri-X film. It should run about $5 for a 36 (actually 37
or 38 frames usually) shot roll which isn't too bad. You wont be able to use red light to see the unexposed film. It is extremely sensitive and any
light will expose it. When I worked with some rolls of it, I used a pitch black closet. Sit in there for 5 minutes. If you can see light coming in at
all, it isn't dark enough. Stuff towels into the crevices around the door if necessary. Developing single pieces will be a lot harder than a whole
roll since you can't look at the film until it has been processed and pieces touching during processing will ruin it. Doing it individually will mean
that one frame will take you @30 minutes...only 18 more hours to go. Maybe you can gut a cheap camera for film advancing capability and build some
lead shielding for it to give it a shutter. The film can then be processed normally. Ask any local colleges if they have a B&W photo lab. Quite a
few do, but getting access is the hard part.
Department of Redundancy Department - Now with paperwork!
'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
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YT2095
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| Quote: | Originally posted by UnintentionalChaos
Ask any local colleges if they have a B&W photo lab. Quite a few do, but getting access is the hard part. |
actually that`s a Great idea! I`m at college all day on Tuesdays and I get on very well with my lecturer and the Lab staff, maybe I might even be able
to do an exchange of some sort, these 3 color rolls for a couple of sheets of B/W paper and Q&A session 
I never considered asking there, Thanks!
\"In a world full of wonders mankind has managed to invent boredom\" - Death
Twinkies don\'t have a shelf life. They have a half-life! -Caine (a friend of mine)
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JohnWW
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B&W film, with AgCl or AgBr as a fine emulsion in gelatine, is stlll used, in large sheets, for X-rays. Only the negatives are usually developed,
B&W paper not being used for the purpose.
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YT2095
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update, I have all the B&W paper and all I need to develop them, I`ve even done test photos with a little pinhole camera I made and they work
fine.
I`ve had the paper in an envelope with the isotope ontop of that and all put in a light tight tin for exactly a week.
it totally failed to show Anything at all 
I so wanted it work, but but sadly it`s a Zero result that way.
I think Next I should try again but this time use a Phosphor as an Intensifier.
\"In a world full of wonders mankind has managed to invent boredom\" - Death
Twinkies don\'t have a shelf life. They have a half-life! -Caine (a friend of mine)
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YT2095
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I`V DONE IT!!!!!!
I`v finally got my X-Rays! here, check these out...
the strange patterns you can see from the Ra sample are from the tiny glass vial I keep it in.
the Th is pretty self evident, it was a piece of Th metal in a thin plastic bag up against the film.
it`s quite plain to see also that the Ra is much "Hotter" than the Th in way of Gamma.
Thanks each for the great ideas and tips given me in this thread (and also via PM ). 
[Edited on 27-12-2007 by YT2095]
\"In a world full of wonders mankind has managed to invent boredom\" - Death
Twinkies don\'t have a shelf life. They have a half-life! -Caine (a friend of mine)
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woelen
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Nice to see that kind of results! How long did you expose the paper to the radiation of the samples, before you developed the paper?
[Edited on 27-12-07 by woelen]
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YT2095
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exactly 1 week to the hour.
I`m thinking now that perhaps 2 weeks for the Th to get any usable X-Ray pics and maybe 4-5 days for the Ra sample as it looks a bit saturated at the
one point.
\"In a world full of wonders mankind has managed to invent boredom\" - Death
Twinkies don\'t have a shelf life. They have a half-life! -Caine (a friend of mine)
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YT2095
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I`ve just set another exposure up, I`m using the Th metal again as it`s a nice an uniform shape, but this time I have sellotaped 2 sewing needles to
it and then presented it to the photo paper, so hopefully I maye get an interesting picture of this.
I plan on leaving this for 2 weeks exposure time.
I still cannot understand WHY that Monazite rock didn`t give Any result at all though????? I know that 1200 DPS isn`t much, but it WILL give a count
through Lead plating and the Th and Ra will not???
it simply doesn`t make Any sense at all to me?
\"In a world full of wonders mankind has managed to invent boredom\" - Death
Twinkies don\'t have a shelf life. They have a half-life! -Caine (a friend of mine)
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woelen
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An exposure of just 1 week? That sounds like high sensitivity of the paper. I have read in my old book (Grundlinien der Chemie, Ostwald, 1919,
Dresden) that the first discovery of radioactivity was after storage of a uranyl salt near some photosensitive plate for many months.
I also do not understand the geiger counting throug lead plate, while on the other hand, no image can be obtained with the monazite rock. The only
thing I can imagine is that the monazite rock gives off very fine dust, which disperses into the air and so it goes around the lead plate to the
Geiger counter.
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YT2095
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it can`t give off dust, it`s in a small zip-lock bag with no apparent holes in it.
and like yourself, I cannot understand this either???
and yes exactly one week to the very Hour itself. the paper is plain Multigrade Ilford IV FB Fiber.
in B&W, I have no real idea how to judge sensitivity as this is all quite New to me, I will say that a Pinhole cam takes 1 hour to make a negative
in overcast cloudy weather during the day.
as for the GM counter, (not all that sensitive either) yes it picks it up quite well through 2 sheets of roofing lead (and no the lead alone gives no
count) I don`t get the 1200 DPS through is, closer to a tenth of that.
AND it will pick it up from several feet away too!
but it will not expose my paper!??????
\"In a world full of wonders mankind has managed to invent boredom\" - Death
Twinkies don\'t have a shelf life. They have a half-life! -Caine (a friend of mine)
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YT2095
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as promised, 2 weeks later here is the x-ray of 2 sewing needles:
it`s not a Great picture and looks better in real life, but you may just be able to make out the eye of one of the needles on the right.
you can clearly see the band across the middle where I sellotaped them into place on the isotope.
\"In a world full of wonders mankind has managed to invent boredom\" - Death
Twinkies don\'t have a shelf life. They have a half-life! -Caine (a friend of mine)
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not_important
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| Quote: | ...
I also do not understand the geiger counting throug lead plate, while on the other hand, no image can be obtained with the monazite rock. The only
thing I can imagine is that the monazite rock gives off very fine dust, which disperses into the air and so it goes around the lead plate to the
Geiger counter. |
Think of the decay chain. Pure thorium or its compounds give off 4 MeV alphas in decay. The decay chain products, which will have built up in any
decently old mineral sample, give off a number of different particles, including roughly 2 MeV betas.
Then there are the photos emitted by the decays. Pure natural thorium gives off a range of x-rays, and has a couple of gamma peaks at (I believe) 60
and 140 KeV. The decay chain products include gammas in the 500 and 900 KeV range, plus some around 2.6 MeV.
With a 14 Gy half life, purified thorium won't have built up much decay products. Also, monazite often contains some uranium, which adds to the decay
spectrum.
Here are several charts of the decay energies of the natural thorium decay chain. Note than in the third reference the top intensity gammas do not
come from the parent 232Th decay, a purified thorium compound or the metal will be lacking in these decays.
http://hepwww.rl.ac.uk/ukdmc/Radioactivity/Th_chain/Thbin.jp...
http://www.bridgeportinstruments.com/literature/isotopes/thn...
http://hepwww.rl.ac.uk/ukdmc/Radioactivity/Th_chain/Thgamma....
So the monazite gives off radiation - gammas - that can make it through lead foil, but at a low rate and possibly not well stopped in the thin
emulsion.
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YT2095
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well it has been suggested that I try Film rather than the papers, the Logic being that it takes several seconds to expose the paper but fractions of
a second to expose film.
(it will also give the advantage of making Positives of these later).
so I May be able to cut down the exposure time to just a day, but being a bit of a Newb with photography, I have no idea how True this is?
Logically it would seem to make sense, but I can imagine that I may lose resolution a little as there won`t be as many "Pixels" in the area (or
whatever they`re called).
btw, Great post Not_Important!
[Edited on 11-1-2008 by YT2095]
\"In a world full of wonders mankind has managed to invent boredom\" - Death
Twinkies don\'t have a shelf life. They have a half-life! -Caine (a friend of mine)
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Texium
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Thread Moved
19-11-2023 at 12:16 |
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