Energy generation in the Sun:
The Proton-Proton Chain
The Proton-Proton Chain
Basic
reaction:
4 1H ® 4He + energy
4 protons have 0.048*10-27 kg (= 0.7 %) more mass
than 4He.
Þ Energy gain = Dm*c2
=
0.43*10-11 J
per
reaction.
Need large proton speed (ó high temperature)
to overcome Coulomb barrier
(electromagnetic repulsion
between protons).
Sun needs 1038 reactions, transforming 5 million tons of mass into energy every second, to resist its own gravity.
T ≥ 107 K = 10 million K
