h a l f b a k e r yYeah, I wish it made more sense too.
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I wonder if a reactor can be made that uses cherenkov radiation from fission + photovoltaic panels to produce energy would be competitive with plain old solar cells.
Water is already used as radiation shielding and its transparent to light as well as being the medium that produces cherenkov light
NASA
can already make solar panels resistant to space radiation
this could potentially be on a small scale competitive with solar cells. You would have to change the fuel to make more of the radiation that produces light, mostly beta particles. You might need to tweak the medium that produces light. Another transparent liquid or a transparent solid. We would probably keep water at least as a cooling agent. With convection and with the temp below boiling it would need no pumps. It would have no moving parts
so its a potentially cheaper reactor specially the initial up front construction costs
Cherenkov radiation
http://en.wikipedia...Cherenkov_radiation
Not something I was familiar with. But very cool. [bungston, Jul 30 2014]
Mostly Blue and Ultra violet ?
http://en.wikipedia...2%80%93Tamm_formula
A formula that says ... duh [popbottle, Jul 30 2014]
[link]
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How small could it be? I mean how much thickness of water is required as a shield? |
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Wkipedia says cosmic rays can initiate Cherenkov radiation in the vitreous of the eye, which is preceived as a light flash. |
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This boils down (hopefully it would not actually boil down) to losses: my understanding is that current nuclear reactors are steam engines, so losses would be the fraction of available energy that turns to heat, and in converting hot steam to electricity. For light it would be the fraction of energy converted to light and ability to turn that light to electricity using a solar cell. |
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If the light is produced by a fast particle traversing a medium, then it would make sense to have it traverse as much medium as possible until it slows to the point that it does not produce light. |
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To compete with solar this would need to be freaking bright. To quote WcW "this might be useful on other planets". I envision a zeroG deep space colony; Cherenkov radiation is used to make an artificial sun out of a blob of liquid water with the radiation source at the center. The radiation source is a salvaged alien ship which is too radioactive to enter explore, but which works great for this application. The ship is also dense and hot, which is helpful as regards hanging onto the water and keeping it liquid. |
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Letting the coffee do its work - the long lived occupants of the disabled alien ship could still be alive in there, but unable to communicate with the outside. They would be discovered in a plot twist halfway through the story. |
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On first glance it would be hard to to this in small scale for a high school science fair. One needs hard radiation which can be dangerous. Certainly radioactive materials are dangerous. |
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I see vmaldia annoed the thorium idea which is: use thorium. I wonder if a Cherenkov reactor could be built at a waste site. Again the payback would need to be such as to make it worth fooling around with radioactive materials, not just entombing them. |
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The intensity of light needed to generate a useful
amount of electricity through photovoltaics is a lot
higher than you would find near a reactor. They're
just not efficient enough for this. [] |
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/intensity/
Maybe that is because the particles are not encouraged to produce maximal light before slamming into graphite or some such. Maybe they would produce more, given the opportunity. |
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There's no reason to avoid trapping/using thermal energy of the radioactive source (already baked). The photovoltiacs could simply be extra. |
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However, when photons are not absorbed and are not allowed to escape, they simply get absorbed and add to the overall heat of the system --which is already being processed by the already-baked thermal-energy conversion system. |
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So the thing to consider are the efficiencies involved. If the photovoltiac-energy conversion efficiency was higher than the thermal-energy conversion efficiency, this Idea would make lots of sense. |
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Solar cells exploit certain specific frequencies. the sun produces a wide range of frequencies. That is what makes it hard to increase their efficiency over 15 per cent or so. If the frequency of Cherenkov is a particular blue color say, then it might be necessary to create a photovoltaic cell
tuned to that particular wavelength by changing the elements used to make the cell. |
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The one solar cell that handles three frequencies is built like a layer cake of three formulations stacked on top of each other. |
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So both intensity and frequency will be important. |
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Some sort of laser might amplify and select for a particular frequency. |
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I thought the Chernekov reactor blew up in
1980something. It was a terrible disaster. |
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I get the feeling this wouldn't be nearly as efficient
as a regular RTG. |
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" the long lived occupants of the disabled alien ship could still be alive in there, but unable to communicate with the outside. They would be discovered in a plot twist halfway through the story. " |
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Great. " New problem, sir - our sun is inhabited. They're thinking about moving. " |
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I was thinking high speed photography might reveal that the radiation source was flickering, and the flicker was actually a distress call. |
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The colonists intercept the arriving rescue ships with more balls of water, with the result that they can make a sun big enough to start farming their asteroids. |
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