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-   -   Re: Thorium Nuclear Reactors (http://www.physicsforums.com/showthread.php?t=142121)

Dirk Bruere at NeoPax Nov4-06 03:38 PM

Re: Thorium Nuclear Reactors
 
G. R. L. Cowan wrote:
> foulbr3@yahoo.com wrote:
>> Hi, I was wondering if a thorium nuclear reactor could be built by
>> confining thorium 232 magnetically as an ionized plasma, mixed with
>> helium 4.
>>
>> My theory is, fission can be induced not only by neutrons splitting a
>> nucleus, but I figure an alpha particle (helium nucleus) can split
>> atoms too. How? By alpha capture instead of neutron capture.
>>
>> Uranium 235 fissions by capturing a neutron, thus becoming Uranium 236.
>> The latter spontaneously decays into fission products plus 3 new
>> neutrons.
>>
>> Does anyone know how to get thorium 232 to fission by alpha capture?
>> Can I just have a bunch of ionized helium and ionized thorium plasma in
>> a tokamak and will they spontaneously be captured? What temperature is
>> needed to overcome the Coulomb repulsion barrier? It would be nice if
>> the temperature worked out to around 10,000 K or so, or substantially
>> less than the 100,000,000 K or so D-T needs for ignition.
>>
>> After 232 thorium captures an alpha particle, it will produce uranium
>> 236 and fission again just like neutron capture. The result is lots of
>> neutrons.
>>
>> Lithium 6 or Beryllium 7 can then be used to convert the neutrons into
>> alpha particles again.
>>
>> The reactions are:
>>
>> Th-232 + He-4 --> U-236 --> FP + 3n
>> 3n + 3 Li-6 --> 3 He-4 + 3 T
>> + -----------------------------------------------------
>> Th -232 + 3 Li-6 --> FP + 2 He-4 + 3 T
>>
>> Thus it seems a "hybrid" nuclear reactor can be built that uses a
>> tokamak but is fission-based in principle (alpha capture induced
>> fission is fission, not fusion). It's hybrid because technically alpha
>> particles "fuse" with the heavy thorium.
>>
>> Any comments?

>
> When alphas strike a heavy nucleus, the fraction
> that do anything other than bounce is pretty small.
> Something like one in 100,000, IIRC, for 11-B --(alpha, n)--> 14-N.
>
> Cold neutrons' initial reaction with 235-U, usually called capture,
> could be considered fusion.
> It has a higher probability than the same with warmer neutrons,
> a difference that is an important power-limiting mechanism
> in 235-U fission reactors,
> so these are hybrids in the same sense
> your hypothetical alpha-particle deal would be.
>
>
> --- G. R. L. Cowan, former hydrogen fan
> Burn boron in pure oxygen for vehicle power:
> http://www.eagle.ca/~gcowan/Paper_for_11th_CHC.html


Or Boron fusion in reactors.
Anyone have any opinions on its viability?
http://en.wikipedia.org/wiki/Aneutronic_fusion

--
Dirk

http://www.onetribe.me.uk/ - The UK's only occult talk show
Presented by Dirk Bruere and Marc Power on ResonanceFM



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