Proton drip line is a concept in particle and nuclear physics. An unstable atomic nucleus beyond the proton drip line will leak free protons. In other words, the proton drip line is the line on the Z, N plane (see table of nuclides) where the proton separation energy is zero; the proton drip line serves as a boundary for proton-rich nuclear existence. This phenomenon may be contrasted with the neutron drip line, as these concepts are similar, but occurring on opposite sides of nuclear stability. In astrophysics, the proton drip line is important in discussions of nucleosynthesis, in particular the rp-process.
Encyclopedia
top
