The so-called rp-process (rp is for rapid proton capture) is the purest form of the rapid proton capture process described above. At proton densities of more than 10 protons/cm and temperatures around 2 × 10 K, the reaction path is close to the proton drip line. The waiting points can be bridged provided that the process time is 10–600 s. Waiting-point nuclides are produced with larger abundances while the production of nuclei "behind" each waiting point is increasingly suppressed.