Chemical Forums
Specialty Chemistry Forums => Nuclear Chemistry and Radiochemistry Forum => Topic started by: Mr. Pink on June 30, 2005, 02:54:32 AM
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Horray! I finally got some beryllium and borated paraffinn wax, courtesy of United Nuclear. I have pictures of them, my trusty Gieger counter and me (heavily censored for legal reasons) I hope to be doing an experiment soon, so expect frequent updates.
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And my other stuff.
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And me.
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What are you planning on doing with it? I love experiments :)
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As some of you might know, when Beryllium is exposed to alpha particles, it emits neutrons. These need a moderator to slow them down so they can be captured by other elements. Paraffin will be my moderator. Americium-241 will be my alpha source (try and guess where i'd get that from). I drew something on paint to illustrate my experiment:
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As some of you might know, when Beryllium is exposed to alpha particles, it emits neutrons. These need a moderator to slow them down so they can be captured by other elements. Paraffin will be my moderator. Americium-241 will be my alpha source (try and guess where i'd get that from). I drew something on paint to illustrate my experiment:
Why in all the world would you want to handle all that hazardeous stuff to do neutron activiation? Have you done the calculations on how much Am-241 you would actually need to reach a reasonable neutron flux?
Maybe you should at least consider obtaining a neutron detector first. Not to mention that borated parrafin, bor, cadmium and lead are not necessarily the best choices for this kind of setup.
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What are neutrons good for anyway? I mean, I know they're important for nuclear weapons, but what about everyday fun? Like making electricity?
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What about nuclear energy for electricty? ::)
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What are neutrons good for anyway? I mean, I know they're important for nuclear weapons, but what about everyday fun? Like making electricity?
Neutrons are usually released when a nucleus undergoes fission. The nucleus breaks apart and in addition to the fragments some neutrons are released. These neutrons cause the chain reaction in a nuclear reactor or weapon. Without them the whole concept would not work.
What Mr. Pink is trying to do is called neutron activation. You can induce radioactivity by bombarding a stable element with neutrons. The neutrons are captured by the stable nucleus and the element can become radioactive. You can then detect the radioactivity, usually by monitoring the gamma radiation emitted. This is a very sensitive and commonly used analytical technique.
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It sould be safe, I'll pour a lead-lined concrete vault. Oh, and I did do the calculations; it would take approx. 1351.351351 Sd (smoke detectors, aka Microcuries) to get 1000 neutrons a second. And why are my materials not the best choices for this setup?
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It sould be safe, I'll pour a lead-lined concrete vault. Oh, and I did do the calculations; it would take approx. 1351.351351 Sd (smoke detectors, aka Microcuries) to get 1000 neutrons a second. And why are my materials not the best choices for this setup?
Well, a couple reasons:
1) 241Am also has a nice gamma line, so a better choice would have been plutonium. Your borated paraffin will not do anything against the gammas, a lead casket will do a little better.
2) Each smoke detector contains ~35 kBq of americium (according to Google), so you have approximately 4.7 E7 Bq, or a couple milliCi if you have 1350 smoke detectors (and if I can count). I do not know where you plan to play with it, but that's not stuff that you want to just handle on the kitchen table or a bench in your garage.
3) Beryllium? The element is incredibly toxic.
4) There are better choices for neutron moderators than borated paraffin.
5) A lead lined concrete vault is ok when the set-up is encased in it. But judging by the set-up that you have, it will not be safe outside of the vault.
I am sure that someone else can think of some more reasons, or correct any mistakes that I have made. Why are you going through all this trouble just to activate some silver? Sure, it is a cool experiment, but what will you do with everything when it is all over?
???
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I did do the calculations; it would take approx. 1351.351351
Don't you feel that "approx. 1351.351351" looks like a bad joke? >:(
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Hey about the amount of Am find an older smoke detector they have like 200 times as much Am as these darn new ones. The one on my ship has a radioactive warning sign on it it has so much but you might wanna use your neutrons on something other than tinfoil. Not only that i do believe the paraffin will slow the neutrons down just not enough. Maybe some heavy water would work but the Russians store there heavy water on the bottom of the ocean. I don't know you but i don't see you breaking into a military guarded nuclear waste silo for some to make this experiment work. Good luck with your experiment and please update us on your progress
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I have absolutely no troubles getting ahold of heavy water. It's not exactly rare. ;)
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Just swing by CANDU in Canada. Ask politely.
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It sould be safe, I'll pour a lead-lined concrete vault. Oh, and I did do the calculations; it would take approx. 1351.351351 Sd (smoke detectors, aka Microcuries) to get 1000 neutrons a second. And why are my materials not the best choices for this setup?
If I take Grejaks number of 35kBq per smoke detector, then your 1350 detectors would add up to about 1.3 milli-Curie of activity. The customary limit for safe handling of actinide elements in a well ventilated fume hood is 10 mico-Curie.
That means you are already a factor of 130 above this limit, and I don’t assume you have a good fume hood in your basement. How about a glove box?
These limits are there for a good reason. If a radioactive element emits an alpha particle, the remaining nucleus is pushed in the opposite direction. This can mean that the radioactive element literally starts to wander around and can contaminate the surroundings. I have worked with high level activities of alpha emitters and I have seen it happen. If you start messing with this much Am-241 there is a very good chance that you will contaminate the room you are working in and inhale some of it yourself.
I hate to say this, but this is a classic case of: Don't try this at home!
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Mr. Pink: How do you plan to get the Americium out of its enclosure?
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I hope I'm not out of line, but I suppose he could simply "rip it out with his BARE hands", for lack of a better word. ;)
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Its less then a microgram in size, he won't be able to see it, thats the point.
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If I take Grejaks number of 35kBq per smoke detector, then your 1350 detectors would add up to about 1.3 milli-Curie of activity. The customary limit for safe handling of actinide elements in a well ventilated fume hood is 10 mico-Curie.
That means you are already a factor of 130 above this limit, and I don’t assume you have a good fume hood in your basement. How about a glove box?
These limits are there for a good reason. If a radioactive element emits an alpha particle, the remaining nucleus is pushed in the opposite direction. This can mean that the radioactive element literally starts to wander around and can contaminate the surroundings. I have worked with high level activities of alpha emitters and I have seen it happen. If you start messing with this much Am-241 there is a very good chance that you will contaminate the room you are working in and inhale some of it yourself.
I hate to say this, but this is a classic case of: Don't try this at home!
(Magic words being in bold) I do have a glove box! Kevlar gloves and a half inch of Pyrex all around. My dad pumps it full of argon for specialized soldering.
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Its less then a microgram in size, he won't be able to see it, thats the point.
Well, the Am is in a gold matrix, and in salt form, not in a mettalic form. Its combined with a huge proportion of (I think) barium salts.
I might also try some cloud chamber experiments, and scinntilator-related experiements, most notably the experiement which led to the discovery of Neutrons in the first place.
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(Magic words being in bold) I do have a glove box! Kevlar gloves and a half inch of Pyrex all around. My dad pumps it full of argon for specialized soldering.
That might not be the kind of glove box that you need. Argon boxes are usually operated at a pressure above atmospheric pressure and allow for some argon to leak outside. They are designed to keep outside air from coming in. You actually want a well vented glove box connected to a HEPA filter system. The glove box has to be kept at a slightly lower pressure than its surroundings to make sure that no air or gas escapes from the box. Some outside air can come inside to ensure proper ventilation. Also, Kevlar gloves may not give you the necessary flexibility to work with your samples.
If you perform your experiments in this glove box, then your dad will not be able to use it for anything else anymore. It will be permanently contaminated. And how are you going to dispose of a contaminated box and the filter?
I would honestly suggest that you reconsider this experiment. You should be able to do the cloud chamber and scintillator experiments without having to disassemble any of the sources contained in the smoke detectors. So how about trying those instead?
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The kevlar is for protection from heat. And I'll try your thing, with the small amount of radiation and cloud chambers. Sounds fun.
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Mr. Pink, you are attempting to do Curie and Joliet's
experiment on "Artificial Radioactivity", correct?
http://www.dartmouth.edu/~physics/labs/p1/lab4.pdf
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Ya, but no, after realizing how little alpha source I have.