Jabarkan Nuclear fusion reaction pathways dari Béntang dalam bahasa sunda

A variety of different nucléar fusion réactions take place inside the cores of stars, depending upon their mass and composition (see Stellar nucleosynthesis).

Stars begin as a cloud of mostly hydrogen with about 25% helium and héavier elements in smaller quantities. In the Sun, with a 107 K core, hydrogen fuses to form helium in the proton-proton chain:

41H → 22H + 2e+ + 2νe (4.0 MeV + 1.0 MeV)

21H + 22H → 23He + 2γ (5.5 MeV)

23He → 4He + 21H (12.9 MeV)

These réactions result in the overall réaction:

41H → 4He + 2e+ + 2γ + 2νe (26.7 MeV)

In more massive stars, helium is produced in a cycle of réactions catalyzed by carbon, the carbon-nitrogen-oxygen cycle.

In stars with cores at 108 K and masses between 0.5 and 10 solar masses, helium can be transformed into carbon in the triple-alpha process:

4He + 4He + 92 keV → 8*Be

4He + 8*Be + 67 keV → 12*C

12*C → 12C + γ + 7.4 MeV

For an overall réaction of:

34He → 12C + γ + 7.2 MeV