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A question for those knowledgeable about radioactivity

Blarg King

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So I came up with an idea, but I'm not entirely sure it would actually work, and I can't seem to find much information about it on Google.

Basically I've seen a couple videos pop up over the last year where people make crude (but functional) "batteries" by sandwiching a bunch of those self-illuminating tritium tubes between two small solar cells. Granted were talking fractions of a volt at microamps of current, but this video got me thinking about interesting niche uses for these devices, and I want to construct one of my own. The only problem is, those little tritium tubes are somewhat expensive.

So my idea to improve cost (and possibly performance) would be to make some DIY radioluminescent paint, except instead of using dangerous and hard to obtain radium, using easy to obtain uranium ore.

Now I know natural uranium on its own is purely an alpha emitter, but many of its decay products are beta emitters in a similar KeV range to the tritium used in the tubes. So what I'm wondering is, could I crush up the uranium ore rocks into a fine powder, and mix it into some phosphor paint to make my own crude self-illuminating paint, and then paint it on to some solar cells to make a basic nuclear battery?

The only thing I can think of why this wouldn't work is that the uranium ore is a lot less energetic than radium or tritium, but even weak luminescence might work. But there could be other factors I'm simply unaware of (this is just a hobby for me after all) so I'm hoping someone here might know more about the subject.

Thanks!
 
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diachi

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could I crush up the uranium ore rocks into a fine powder

Thanks!

That sounds like a terrible idea. I'm no expert on the matter but you really don't want to be ingesting an alpha emitter like that, or a beta emitter for that matter. Uranium ore dust sounds like a real easy way for that to happen.

I'd imagine you'd get even less power than a DIY tritium cell, which has such a low power output that there's already very few consumer applications for it. In most cases you'd be better off using a small lithium cell, a super capacitor, a solar cell on its own or a combination thereof.

Even the commercial tritium cells only found uses in very niche markets.

 
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Blarg King

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That sounds like a terrible idea. I'm no expert on the matter but you really don't want to be ingesting an alpha emitter like that, or a beta emitter for that matter. Uranium ore dust sounds like a real easy way for that to happen.
Probably should have added I would wear safety gear. I don't even open my radioactive collection without a good quality respirator on.

I'd imagine you'd get even less power than a DIY tritium cell, which has such a low power output that there's already very few consumer applications for it. In most cases you'd be better off using a small lithium cell, a super capacitor, a solar cell on its own or a combination thereof.

Even the commercial tritium cells only found uses in very niche markets.
I know its extremely niche, but theres just something about a "battery", even an extremely weak one, that can keep producing energy for such a long time. And I just like building challenging devices.

I did actually have one use in mind. My college has a 3D printer, and they're always pushing us to make unique things with it, and I think making something similar to the video I linked would be cool. A small moving sculpture that will keep running self contained for at least a decade.
 
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CurtisOliver

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The most effective use of radioactive substances as a continuous source of power so far is RTG/RITEG's. Used primarily by NASA, they use the principle of TEG (Thermoelectric generators) and the heat produced by decay to generate electricity.
I've seen tritium used for solar projects before. Neat idea, but very low power. As for using Uranium, a bad idea IMO also. Also wouldn't amount to very much. U 238 is a very weak source and can't even be used for good old fashion fission. Whilst safety wise you don't need to worry too much about using U 238, one of its decay products you do need to consider and that is Radon (Ra 226).
 

Blarg King

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The most effective use of radioactive substances as a continuous source of power so far is RTG/RITEG's. Used primarily by NASA, they use the principle of TEG (Thermoelectric generators) and the heat produced by decay to generate electricity.
Yeah, but any radioactive material that generates enough heat to be useful is probably illegal and/or difficult to obtain, not to mention would probably irradiate half my neighborhood.

I've seen tritium used for solar projects before. Neat idea, but very low power. As for using Uranium, a bad idea IMO also. Also wouldn't amount to very much. U 238 is a very weak source and can't even be used for good old fashion fission. Whilst safety wise you don't need to worry too much about using U 238, one of its decay products you do need to consider and that is Radon (Ra 226).
Hmm. I wonder if theres another source of radiation I could use then? Could Americium from smoke detectors work? It wouldn't be terribly difficult to pull the Americium out of disposed smoke detectors (Im having radioactive boyscout flashbacks). Theres also those little plastic isotope discs United Nuclear sells, but Im pretty sure those cost more than tritium vials :/

I do take radon into account with all my uranium stuff I own, everything is triple sealed in have duty plastic bags and then locked in an airtight container. (although supposedly most weak uranium sources don't produce much radon anyways)

Ah well. I had a feeling this idea was a longshot (otherwise Im sure someone would have done it already). Perhaps I'll just save up and make a tritium tube battery after all.
 

CurtisOliver

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Yeah, but any radioactive material that generates enough heat to be useful is probably illegal and/or difficult to obtain, not to mention would probably irradiate half my neighborhood.



Hmm. I wonder if theres another source of radiation I could use then? Could Americium from smoke detectors work? It wouldn't be terribly difficult to pull the Americium out of disposed smoke detectors (Im having radioactive boyscout flashbacks). Theres also those little plastic isotope discs United Nuclear sells, but Im pretty sure those cost more than tritium vials :/

I do take radon into account with all my uranium stuff I own, everything is triple sealed in have duty plastic bags and then locked in an airtight container. (although supposedly most weak uranium sources don't produce much radon anyways)

Ah well. I had a feeling this idea was a longshot (otherwise Im sure someone would have done it already). Perhaps I'll just save up and make a tritium tube battery after all.
Lol, I definitely was not suggesting going about building an RTG. :eek:
No way. :tsk: :p

Tritium based luminescence has shown surprisingly good results for electricity generation IMO. Not going to be powering anything substantial anytime soon. But you could get a small circuit board to run. Or even go all out and make a cheap 1mw 650nm powered by Tritium. :whistle:
Should be able to power a pocket calculator for 6-7+ years.

Just a warning though. If you manage to obtain tritium vials unsealed, be extra careful handing them. I bought 10 vials and lets just say I now have 9. :eek: The 4mm x ~25mm vials tend to be the brightest. The 80mm are supposedly not as bright.
 

ArcticDude

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Lol, I definitely was not suggesting going about building an RTG. :eek:
No way. :tsk: :p

Tritium based luminescence has shown surprisingly good results for electricity generation IMO. Not going to be powering anything substantial anytime soon. But you could get a small circuit board to run. Or even go all out and make a cheap 1mw 650nm powered by Tritium. :whistle:
Should be able to power a pocket calculator for 6-7+ years.

Just a warning though. If you manage to obtain tritium vials unsealed, be extra careful handing them. I bought 10 vials and lets just say I now have 9. :eek: The 4mm x ~25mm vials tend to be the brightest. The 80mm are supposedly not as bright.
Or you could just get Russian Nickel-63 beta emitter battery, lol :p

 

Cyparagon

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The power density won't exceed a lithium primary cell. A tritium cell might last for 20 years under the right conditions, but so does a CR2032. It is not economical and has no advantages.
 

Blarg King

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The power density won't exceed a lithium primary cell. A tritium cell might last for 20 years under the right conditions, but so does a CR2032. It is not economical and has no advantages.
Surely it must have some advantages in some applications, otherwise there wouldn't be commercially available tritium batteries?
 

WizardG

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Wider operating temperature range is the only one I can think of. A tritium cell should work fine bathed in LN2.
 

Nordhavn

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Tritiated aerogels are the brightest betalights. RTG is the way to go if you need a steady source of power for years that's outside of the microwatt range.
50ci worth of fresh trasers coupled to 20% efficient PV cells could power a LCD calculator just fine. But then again so could the cells (actually much smaller cells) from just room light. Which, btw, the calculator needs as its LCD is not illuminated! ;)

Really low power CMOS "gathering nodes" used in remote places, say at the bottom of the ocean, could benefit from a betaphotovoltaic generator. Unlike RTGs, there's no shielding required and if destroyed the amount of radioactive contamination is negligible.
 

Benm

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There is a fundamental problem with the idea of using something like uranium ore as the energy source. First of all it will not really produce enough radiation to get a usable amount of power, but let's forget about that for a bit, perhaps you only need a picowatt or something.

One thing i see going very wrong here is in the basic concept of it:

Tritium is a low energy, pure-beta emitter, which works well for this application: The beta radiation can excite the phosphors to produce light, but do not have enough energy to make it even through the glass envelope of the tube.

If you were using uranium ore you'd probably get a mixture that will during it's decay emit gamma rays and/or high energy beta's that could make it through the glass. On their way out they can damage the 'solar panels' you use to capture electrical energy.

So for a very long term solution this is not the best thing to have - it could be such that your radiation source is good for a million years, but your solar panels are destroyed in a very short amount of time.

RTG's have this problem too, but in real application purified isotopes are used. This could be something like Pu-238 which only has alpha decay, to U-234, which also decays by alpha mostly (unless it spontaneously fissions). This prevents damage to the PN juctions that get eletrical energy from the thermal gradient.

In short i presume that it could work with radioactive ore, but practically not for very long since it would destroy itself.
 

Blarg King

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So one other thing I cant find much about through google, is it only beta radiation that excites phosphors? I cant find any info if alpha particles can do it, nor gamma, though I feel like gamma would most likely go through a phosphor without imparting much energy into it.
 

Cyparagon

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Alpha decay has ridiculous energy behind it. I don't see why it wouldn't have an issue exciting phosphor... except it would also probably slowly degrade/destroy the phosphor.
 

Benm

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Gamma radiation could certainly interact, this is used in scintillation counters and such. I'm not sure how efficient it would be, as as you state the chances of them flying straight through the phosphor are pretty high unless you have a very thick layer of phosphor based on heavy nuclei.

I'm not really use about alpha radiation though... but there is another aspect that can be used to go straight from alpha radiators to electrical power: alpha radiation are basically helium-4 nuclei, but fully stripped of electrons, so they can recombine with any material they hit, moving 2 electrons from the target. This can provide very high voltage potentials albeit at very tiny currents if the target and source are electrically conductive.

For most real world applications the RTG is the solution of choice though - it has proven itself in many applications, is pretty robust, and can be designed to last for decades or even ages depending on the isotope of choice.

As a private experimenter you do not really get an 'isotope of choice' though - you cannot buy lumps of purified Pu-238 on ebay like you can get the tritium lights ;)
 

Seoul_lasers

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In nature Uranium238 always has some U235 in it (fractions of a %) so while U238 is an alpha emitter / you'll get beta and gamma from all the decay products associated with U235&U238.

The activity isn't going to be enough to produce much usable energy using a phosphor.
Purifying the ore further into a metal would be better, though doing so violates Canadian Nuclear regulatory guidelines, and is extremely hazardous to do so.
 




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