The
rp-process (rapid proton capture process) consists of consecutive proton captures onto
seed nuclei to produce heavier elements. It is a
nucleosynthesis process and, along with the
s process and the
r process, may be responsible for the generation of many of the heavy elements present in the universe. However, it is notably different from the other processes mentioned in that it occurs on the proton-rich side of stability as opposed to on the neutron-rich side of stability. The end point of the rp-process (the highest mass element it can create) is not yet well established, but recent research has indicated that in
neutron stars it cannot progress beyond
tellurium. The rp-process is inhibited by
alpha decay, which puts an upper limit on the end point at
105Te, the lightest observed alpha decaying nuclide, though lighter isotopes of tellurium could potentially be proton-bound and alpha decaying.