Rp process

The rp (rapid proton capture) process consists of a series of proton catches by initial nuclei that give rise to heavier elements. It is a form of nucleosynthesis, together with the processes r and s, and is responsible for the formation of a large majority of the heavy elements (above the Faith) present in the Universe. The end point of the rp process (the heaviest element that can be obtained by these reactions) is not precisely known, but it is believed that neutron stars can not obtain elements beyond tellurium.

The rp process occurs in very high temperature conditions, so that the protons can overcome the potential barrier that is necessary for them to enter the nucleus. In addition, a rich hydrogen environment (free protons) is needed so that the high proton flow needed is possible. The necessary "seed" nuclei are formed from rupture reactions during the CNO cycle.

This process is thought to occur in binary systems made up of white dwarfs or neutron stars and red giants. In this scenario, the red giant injects a large amount of hydrogen into its massive partner, increasing the temperature and creating the necessary conditions for this process to take place.

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