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Safely enclosed Radioactive Battery

Unidirectional radioactive material on PV cell enclosed
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Lightweight electric battery consisting of a sheet of unidirectional radioactive material on a thin lightweight sheet acting as a PV cell enclosed in material that does not let out the radiation, on the side that radiates. (I remember such a material from the days I was a student in the physics lab).
pashute, Mar 11 2010

Nuclear pacemakers (see p 57) http://home.comcast...tope_pacemakers.pdf
"although this form of nuclear-electric generator dates back to 1913, few applications have been found for the extremely low currents and inconveniently high voltages provided" But perhaps unidirectioal radioactive material would improve efficiency. [mouseposture, Mar 11 2010]

[link]






       There is a German company that makes a coating for the balls in pebble-bed reactors that is strong enough to stop a meltdown even in an unattended, broken reactor. I would think the same material would work in your concept. Bonus in that it isn't going to breach containment if your cat knocks it off the kitchen table, and that it just has to be put in a place it won't get seriously crushed until it decays, because the packaging will make it practically harmless. Actually, I suppose it's less harmless where the contacts stick out. We'll just put stickers on them that say "Point away from things you like". Also, I think the extra materials cost for a step-down converter would be well worth the cost of having a self-charging battery in a laptop. Of course, considering the cluserfucky state of the Yucca Mountain Project lately, the costs associated with disposing of exhausted but still potentially dangerous components will remain inhibitory. Which means that they'll have to charge the (adjusted) cleanup cost in advance on the purchase price so they can wave it under you nose as rebate to get the people who throw something that could release gamma radiation after it degrades into the garbage, but naturally are too fiscally responsible to overlook those forty bucks waiting for their broken toy back at the store. Then the actual materials disposal has to be undertaken without the lowest bidder just stuffing a few U-Stor-It's full of them and padlocking the door... *shiver* I dunno, pretty Fallout, guy.
victory, Mar 11 2010
  

       Forgive my ignorance, but what is //unidirectional radioactive material //?
coprocephalous, Mar 11 2010
  

       A few of these could make a terrible bomb. Care needs to be taken that a random person cannot just pack the cores together to reach critical mass, such as making sure the material is "diluted" enough that radioactive density would never be high enough when attempted.   

       Public acceptance of radioactive substances would be an amazing turning point in society.. My personal favorite so far is the nuke powered jet, the turbine looks mostly normal but the combustion chamber is simply control rods put near eachother to crank out heat.
AutoMcDonough, Mar 11 2010
  

       Radioactive material is quite abundant, and nothing that dangerous (atom bomb wise, of course the radioactivity itself is extremely dangerous). I'm not talking about Uranium.   

       I'm not sure how it was achieved but as a young student at university we held in our hands a small lightweight disk that emitted alpha particles in one direction only (like a flashlight).
pashute, Mar 11 2010
  

       That's because alpha particles are low-energy and incredibly simple to stop with a sheet or two of paper.
RayfordSteele, Mar 11 2010
  

       well, as a power source that is designed to compete with stored energy, the actual energy density is a key attribute, one that people will try to maximize. It might not be uranium, but if the energy density is high enough then you have some trouble. I assume that this "maximum energy density" can be a regulated limit, strictly to avoid the home-made nuke.   

       anyways.. if both sides of the battery were a heavy metal such as copper, wouldn't this serve the dual purpose of carrying out the power and blocking the radiation from escaping?
AutoMcDonough, Mar 11 2010
  

       still waiting for some explanation of the unidirectional radioactive material. Not so sure that this exists.
WcW, Mar 11 2010
  

       maybe that in itself is the key to the cell. Like the two doped layers of silicon that make a diode, they may be a way to make radiation flow in one direction without just blocking half of it.
AutoMcDonough, Mar 11 2010
  

       sweet. That in alone would be a half baked invention.
WcW, Mar 11 2010
  

       (link) Baked, apparently, apart from the unidirectional part. And *why* unidirectional? Why not sandwich the emitter between two PV sheets? Especially why not in light of [RayfordSteele]'s comment.
mouseposture, Mar 12 2010
  

       yeah not finding the unidirectional nuclear (alpha beta gamma) radiation source. Suspect it may be impossible. not a deal breaker for the idea just an observation.
WcW, Mar 12 2010
  

       I thought the problem was they don't give off that much energy. space probes use nuclear batteries but they run on the equivalent of 100 watts or so and those batteries are huge.   

       a AA sized battery of a highly radioactive element simply doesn't give off that much useable electricity. and that discharge rate is constant.
metarinka, Mar 13 2010
  

       always the problem with isotopes, to cold and all you get is a nasty sun burn, too hot and things go bang.
WcW, Mar 13 2010
  

       Actually, the output isn't constant. it decreases in accordance with the half-life.
ye_river_xiv, Mar 13 2010
  

       on the other hand the available output is more stable than any other solution that I can think of. With some careful design I suspect you could maintain 90% of radiation output for a thousand years. Is there anything that currently comes anywhere near that?
WcW, Mar 13 2010
  

       I hate to be picky*, but doesn't this idea amount to "make nuclear batteries acceptable to the public"?   

       This idea suggests nothing new (apart from the unidirectional business, which doesn't exist), and is basically saying "shield nuclear batteries to make them safe", which I believe is already done. People just don't like radiation, for the same reason people don't like GM crops - i.e., good old redneck irrationality.   

       Aside: if the tobacco industry were forced to print "The tobacco in these cigarettes contains nuclear atoms.", that would probably halve the smoking rate overnight.   

       *not actually true.
MaxwellBuchanan, Mar 13 2010
  

       //*not actually true.// [marked-for-tagline]
mouseposture, Mar 13 2010
  

       Sorry, didn't follow the discussion. (Is there a way to get HB to email me for annos on my ideas? Perhaps a FireFox addon? OK I admit: I still don't know what to do with RSS. Is there HB RSS?)   

       [Rayford] explained the unidirectional. Sorry for bringing it up. I did not know that it is not a physical phenomenon, but rather simply an instructive device for our physics class.   

       and [mouse] baked the whole thing :-(
Actually there's an even better quote from the next page: First, the radioactive energy is converted into light by a scintillating phosphor. Second, the photovoltaic cell converts the light into an electrical output. Theoretically, the phosphor-photovoltaic generator has the potential of higher power density than the betavoltaic generator. In practice, phosphor degradation has limited its application.
pashute, Mar 18 2010
  

       A unidirectional material = an incline.
wjt, Mar 18 2010
  

       i don't think that radiation cares about inclines one way or the other.
WcW, Mar 18 2010
  

       the most efficient photovoltaic cells are around 30% efficient, and that is because they are wide-spectrum. I would expect more like 10% from such a narrow source as radioactively activated phosphor.. who know what sort of efficiency you get there. I'd hope there is a better way, one that doesn't have to go through 2 energy conversions.
AutoMcDonough, Mar 18 2010
  
      
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