The distributions of the temperature excess of alphas to protons (epsilon) were studied using Parker Solar Probe measurements for Encounters 2 through 14. The distributions were mapped based on heliographic distance, Coulomb number, plasma beta, and Alfven Mach number (M (A) ). The importance of collisional effects in the thermalization of solar wind is observed for a wide range of Coulomb numbers. The distributions correlate better with N beta and NM (A) than just N. Furthermore, evidence was found for a narrow region immediately above the Alfven surface (1 < M (A) < 2) where epsilon has values much higher than the mass ratio.
QC 20240326