Im probably confused and am getting this all backwards but Is it necessary to have 2 different isotopes of hydrogen for hydrogen fusion to occur? Water has 2 hydrogen atoms..wouldn't that be sufficient? Reading on how scientists attempt it now they use Deuterium-Tritium what's the difference between those elements and the elements that are in H20?

 

What is the end product of hydrogen fusion?

How many protons and how many neutrons does it have?

Where does everything come from if you just fuse two "normal" hydrogen atoms?

 

Deuterium-Tritium what's the difference between those elements and the elements that are in H20?

Common hydrogen has just one proton in its nucleus, whereas deuterium has 1proton and 1 neutron, while tritium has 1 proton and two neutrons.

The reason deuterium and tritium are used in most present experiments to generate fusion on earth is that they fuse much easier (at a lower temperature), than normal hydrogen.

 

I think, but am not sure that a nucleus with 2 protons and no neutrons would be unstable, hence the heavier isotopes. The naturally occurring He nucleus has 2 protons and 2 neutrons.

Bob

 

Im probably confused and am getting this all backwards but Is it necessary to have 2 different isotopes of hydrogen for hydrogen fusion to occur? Water has 2 hydrogen atoms..wouldn't that be sufficient? Reading on how scientists attempt it now they use Deuterium-Tritium what's the difference between those elements and the elements that are in H20?

The use of isotopes isn't necessary, but it is preferable. Fusion of neutron-free hydrogen (as occurs in our own sun) yields a much weaker reaction than deuterium with tritium.

 

I think, but am not sure that a nucleus with 2 protons and no neutrons would be unstable, hence the heavier isotopes. The naturally occurring He nucleus has 2 protons and 2 neutrons.

Bob

Indeed, Helium-2 or a diproton is unstable with a half-life of less than 1 nanosecond.

 

Indeed, Helium-2 or a diproton is unstable with a half-life of less than 1 nanosecond.

Ah, but it probably decays to deuterium, right?

 

 

Ah, but it probably decays to deuterium, right?

Not very likely, there are two decay modes for 2-Helium (2 protons and no neutrons)

1. Proton emission leaving two 1-Hydrogen atoms >99.99%
2. β+ decay or the emission of a positron yielding a 2-Hydrogen(Deuterium) consisting of a proton and a neutron <0.01%

 

The use of isotopes isn't necessary, but it is preferable. Fusion of neutron-free hydrogen (as occurs in our own sun) yields a much weaker reaction than deuterium with tritium.

Amazing fact: the Sun's fusion only produces around 100 W/m^3. About the same power as an incandescent light bulb (per m^3).

 

I suspect without knowing we will need deuterium hydrogen isotopes to fuse. The sun does fusion by virtue of sheer power where isotopes don't matter. Since we don't have gravity control we are going to have to make due by i using slightly unstable isotopes. Just my 2¢.

 

An interesting alternate reaction is boron-hydrogen fusion, which a number of fusion experimenters are working towards.
It is aneutronic (generates few dangerous neutrons unlike the deuterium-tritium reaction), with the primary fusion product being fast moving charged alpha particles (ionized helium).
The moving electric field from this can, in principle, be converted directly to electricity, instead of heating water to generate steam and run a turbo-generator as the deuterium-tritium reaction requires.

 

An interesting alternate reaction is boron-hydrogen fusion,

That would give carbon.Then we could burn that to raise steam. No, wait. . . . . .

 

So if two protons fuse then immediately go back to two protons, no net energy is produced. Which means only the 0.01% that decay to deuterium nuclei produce any output. No wonder we need to use heavy hydrogen isotopes.

 

That would give carbon.

Where did you get that?
The reaction produces alpha particles:

Of course in a star, three alpha particles can occasionally combine to form carbon.

 

Where did you get that?
The reaction produces alpha particles:
View attachment 280992

Because it produces the right number of neutrons and protons for carbon-12 which is a particularly stable nucleus
(Though it was mainly for the comedy value of burning it)

 

Can't wait for the iron stars.

 

Can't wait for the iron stars.

You are living on one.

 

Can't wait for the iron stars.

I don't follow(?)