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Treant

(1,968 posts)
11. Beta decay takes care of that.
Mon Dec 21, 2015, 04:57 AM
Dec 2015

Usually, in a basic small stellar core (Sun sized or smaller), two hydrogen (simple protons) bang together and fall apart very quickly. Diproton (helium-2) is incredibly unstable. This happens most of the time, with no net energy absorbed or released.

Rarely, one of the protons decays to a neutron, and the diproton becomes deuterium. That's then free to fuse with another hydrogen atom to produce helium-3. Two helium-3 atoms will then fuse to form a helium-4, and release two hydrogen atoms again as well.

That happens often enough to maintain hydrostatic equilibrium of the star. If it didn't, pressures and temperatures would increase until enough diproton had the chance to decay and release enough energy to do so.

Larger stellar cores (just a tiny bit more massive than our Sun and upward) use the CNO (carbon, nitrogen, and oxygen) process primarily instead.

One has to use deuterium. longship Dec 2015 #1
Deuterium is relatively easy to concentrate, though muriel_volestrangler Dec 2015 #2
Yup! longship Dec 2015 #3
3H, not 3He. nt thereismore Dec 2015 #4
It both works, one reaction throws away a neutron, the other reaction throws away a proton jakeXT Dec 2015 #5
Nice, thanks. nt thereismore Dec 2015 #6
Elemental helium has no neutrons. Angleae Dec 2015 #7
AFAIK, almost all helium has 2 neutrons. longship Dec 2015 #8
On earth yes. In space no. Angleae Dec 2015 #9
Helium-2 is extremely unstable. longship Dec 2015 #10
Beta decay takes care of that. Treant Dec 2015 #11
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