Why does fusing helium require a significantly higher temperature than fusing hydrogen?

Answer

Helium nuclei experience a much stronger repulsive force

Helium nuclei (alpha particles) carry twice the positive charge of a single proton, resulting in a much stronger mutual electrical repulsion that must be overcome by higher kinetic energy.

Why does fusing helium require a significantly higher temperature than fusing hydrogen?

#Videos

Nuclear fusion in the sun. The 4 steps from hydrogen to helium.

sunstarFusionnuclearhelium