  We analyze measured proton and electron temperatures in the high-speed solar
wind in order to calculate the separate rates of heat deposition for protons
and electrons. When comparing with other regions of the heliosphere, the fast
solar wind has the lowest density and the least frequent Coulomb collisions.
This makes the fast wind an optimal testing ground for studies of collisionless
kinetic processes associated with the dissipation of plasma turbulence. Data
from the Helios and Ulysses plasma instruments were collected to determine mean
radial trends in the temperatures and the electron heat conduction flux between
0.29 and 5.4 AU. The derived heating rates apply specifically for these mean
plasma properties and not for the full range of measured values around the
mean. We found that the protons receive about 60% of the total plasma heating
in the inner heliosphere, and that this fraction increases to approximately 80%
by the orbit of Jupiter. A major factor affecting the uncertainty in this
fraction is the uncertainty in the measured radial gradient of the electron
heat conduction flux. The empirically derived partitioning of heat between
protons and electrons is in rough agreement with theoretical predictions from a
model of linear Vlasov wave damping. For a modeled power spectrum consisting
only of Alfvenic fluctuations, the best agreement was found for a distribution
of wavenumber vectors that evolves toward isotropy as distance increases.
