Java Astro Lab: A Collection of Applets for Astronomy

Nucleosynthesis Processes

Proton - Proton (PP) Chain

Stars like our Sun generate energy by fusing Hydrogen into Helium. Several chain reactions 4 (11H) -> 42He are possible, depending on temperature in the center of the star. When this temperature is below 20 million K, the reactions take the proton - proton (PP) chain path:

The first reaction in the PP chain:

11H + 11H -> 21H + e++e

(Java animation).

The second reaction in the PP chain:

21H+ 11H -> 32He +

(Java animation)

The third reaction in the PP chain:

  32He + 32He-> 42He + 2( 11H)

(Java animation)

Credits: The JAVA animations were made using the Collision applet created by Nicolas Delerue.