The purpose of the present paper is to describe the effects of
electron-electron collisions on proton electronic stopping in plasmas of
any degeneracy. Plasma targets are considered fully ionized so electronic
stopping is only due to the free electrons. The stopping due to free
electrons is obtained from an exact quantum mechanical evaluation in the
random phase approximation, which takes into account the degeneracy of the
target plasma. The result is compared with common classical and degenerate
approximations. Differences are around 30% in some cases which can produce
bigger mistakes in further energy deposition and projectile range studies.
We focus our analysis on plasmas in the limit of weakly coupled plasmas
then electron-electron collisions have to be considered. Differences with
the same results without taking into account collisions are more than
50%.