Deuterium

[Zolar V]

Are D-D reactions Self Sustaining and exothermic?

[UC]

What the heck are you talking about? deuterium behaves almost identically to regular old hydrogen.

[Zolar V]

oh, that is unexpected form an isotope.. but ok,

what do you suggest then for a slightly exothermic, self sustaining reaction?

[Moontanman]

Zolar, what type of reaction are you thinking of here? Chemical? If so then it is more or less identical to regular hydrogen, nuclear? then no it is not any more self sustaining under normal conditions than hydrogen fusion would be. In other words nothing at all. Under the conditions of the sun and possibly the center of large planets like Jupiter then yes D-D reactions do indeed work like nuclear fusion, are easier to fuse, and are self sustaining until the deuterium runs out. It has been postulated that Jupiter had self sustaining nuclear reactions until it's supply of deuterium ran out. At this time Jupiter would have glowed red hot from these reactions and the in-fall of matter. Jupiter probably looked like a red glowing ball for many thousands of years.

[Zolar V]

I was thinking about a nuclear reaction, what then may i ask, would be a good chemical-chemical reaction that is exothermic and self sustaining. also, available for civi use.

 

i want to make a miniature thermonuclear reactor.. think like slightly larger than a cell phone small.

[Moontanman]

I was thinking about a nuclear reaction, what then may i ask, would be a good chemical-chemical reaction that is exothermic and self sustaining. also, available for civi use.

 

Actually a fuel cell should work for this, it of course takes fuel but it is well with in the possibilities of current technology.

 

 

i want to make a miniature thermonuclear reactor.. think like slightly larger than a cell phone small.

 

Then you wan to look into aneutronic nuclear reactions, helium 3 is often cited as the best fuel, deuterium deuterium reactions produce neutrons which require quite a bit of shielding to be safe for bystanders, lol

[Zolar V]

Actually a fuel cell should work for this, it of course takes fuel but it is well with in the possibilities of current technology.

 

 

 

 

Then you wan to look into aneutronic nuclear reactions, helium 3 is often cited as the best fuel, deuterium deuterium reactions produce neutrons which require quite a bit of shielding to be safe for bystanders, lol

 

pff the reactor in question is much to small to produce any significant source or radiation that exceeds background radiation.

[Moontanman]

pff the reactor in question is much to small to produce any significant source or radiation that exceeds background radiation.

 

If this is true then it wouldn't produce significant amounts of useful energy.

[Zolar V]

If this is true then it wouldn't produce significant amounts of useful energy.

 

its not meant to produce much energy. only enough to power a model

[Cap'n Refsmmat]

Wait, are you thinking of nuclear fusion with deuterium? In a model?

[Zolar V]

fusion?? NO, definitely not, i am thinking fission.. and exothermic..

[Moontanman]

fusion?? NO, definitely not, i am thinking fission.. and exothermic..

 

Fission? With deuterium? You must know something no one else does.

[Zolar V]

well then i suppose my presumption was wrong, in that case like i stated above, have you any ideas on a exothermic sustainable reaction then?

obviously not uranium because that is expensive and hard to obtain in the form and quantity i need it in, and hard to use for what i need it in.

 

as for the deuterium i was assuming that being an isotope that it was not stable and as a result decayed, and a d-d reaction with a catalyst would expedite that decay releasing exothermic energy. the reason i picked deuterium is due to its availability to "civilians" i say civilians even though im military because i would still fall under that category when trying to buy a nuclear type fuel.

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oh yes, fyi, i do follow fusion reactors and such. i just want a nuclear reaction that is exothermic and self sustaining..

[Moontanman]

well then i suppose my presumption was wrong, in that case like i stated above, have you any ideas on a exothermic sustainable reaction then?

 

As far as i am aware there are no nuclear reactions that are capable of being tiny, safe, and capable of producing enough energy to even come close to doing what you suggest, even on a tiny scale of a model. In fact it would probably be easier to do on a large scale than a tiny one.

 

 

obviously not uranium because that is expensive and hard to obtain in the form and quantity i need it in, and hard to use for what i need it in.

 

Not to mention dangerous and not energetic enough to do what you want.

 

as for the deuterium i was assuming that being an isotope that it was not stable and as a result decayed, and a d-d reaction with a catalyst would expedite that decay releasing exothermic energy.

 

Deuterium is stable, tritium is not but it would still not work in a fission reaction.

 

 

the reason i picked deuterium is due to its availability to "civilians" i say civilians even though im military because i would still fall under that category when trying to buy a nuclear type fuel.

 

I doubt any nuclear material capable of producing energy significant enough to do what you suggest would be legal.

 

 

 

oh yes, fyi, i do follow fusion reactors and such. i just want a nuclear reaction that is exothermic and self sustaining..

 

Then you know there are no tiny nuclear energy sources?

[Zolar V]

are you sure about that?

so you are saying that you cannot have a thermonuclear reactor that is scaled down?

 

so if i were to take 2 1in r^2 uranium rods, (control rods) and placed them side by side in a 3x3x3 in well that the resulting fission would exhibit exothermic energy?

 

if so please bring your equations to bear, i would much like to see them.

[Cap'n Refsmmat]

I am not sure you can easily construct a small scale nuclear reactor that meets the following criteria:

1. Lightweight
   
2. Good power output
   
3. Minimal radiation exposure to those nearby
   

 

Remember, power is generated in a reactor by boiling water into high-pressure steam and driving a steam turbine. The piping and turbine will add significant weight. And when you have a reaction going critical, you have lots of neutrons running around, as well as other radiation, so you need a significant amount of shielding. (Think lead.)

 

Even a small mass of uranium going critical is enough to kill someone from radiation exposure.

 

Remember you have to achieve a sufficient mass of uranium to sustain a nuclear reaction. You can't just put in a tiny chunk and expect anything to happen.

[Zolar V]

noted.

so taking the above parameters, is there a something-something reaction that is exothermic and somewhat self sustaining?

[Cap'n Refsmmat]

http://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator

[Moontanman]

Good luck with using a RTG to power a floating island of any size. The energy density necessary to make something float just isn't there.

[insane_alien]

he could always make it balloon based. then you don't need a powersource to maintain buoyancy.

[Leader Bee]

The only thing that I can think of that comes close to what you need is a farnsworth Fusor, it uses deuterium as it's fuel source but I doubt it will output enough energy to be of any use other than as a viability demonstration.

 

The components are apparently relatively easy to come by for civilians but I have never attempted construction myself.

 

http://en.wikipedia.org/wiki/Fusor#Hobbyists

[Zolar V]

Good luck with using a RTG to power a floating island of any size. The energy density necessary to make something float just isn't there.

 

i dont need energy density to be able to force the island to float. all i need is a constant power input, energy density could be maintained via capacitors.

[insane_alien]

he meant power density. the energy density of an RTG is actuall quite good but drawing a large amount of power is nigh on impossible. for a large structure like a floating airport you'd need it(the RTG) to weigh hundreds of tonnes.

[Zolar V]

he meant power density. the energy density of an RTG is actuall quite good but drawing a large amount of power is nigh on impossible. for a large structure like a floating airport you'd need it(the RTG) to weigh hundreds of tonnes.

 

true, but for the real floating island i would just use nuclear, i would not bother with deuterium. however this is supposed to be a model. so my thought process was "think of a light isotope, decide if it is exothermic and self sustaining, use it small scale as a representation o fthe large scale. and hope it provides atleast some power to the model it self. Battery backup my be needed"

^my thought process, i came up wiht deuterium, for a light isotope, and my question here was is it exothermic and self sustaining. since then i dont think anyone has actually answered my question at all.

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huh... missed the rtg link post..reading it now

[insane_alien]

deuterium will not emit any heat on its own. you'd need a fusion reactor to get any heat and we haven't really built one that can get to a Q>1 level yet(its been done briefly but it wouldn't really be worth it). and this is with massive reactors.

 

with fusion, the bigger the reactor the better. smaller makes it worse.

 

you won't really be able to build an energy generator suitible for the scale of the model. the best would be getting an IC engine for a model plane or similar and hooking it up to an alternator.