  We describe the energy budget of a coronal mass ejection (CME) observed on
1999 May 17 with the Ultraviolet Coronagraph Spectrometer (UVCS). We constrain
the physical properties of the CME's core material as a function of height
along the corona by using the spectra taken by the single-slit coronagraph
spectrometer at heliocentric distances of 2.6 and 3.1 solar radii. We use
plasma diagnostics from intensity ratios, such as the O VI doublet lines, to
determine the velocity, density, temperature, and non-equilibrium ionization
states. We find that the CME core's velocity is approximately 250 km/s, and its
cumulative heating energy is comparable to its kinetic energy for all of the
plasma heating parameterizations that we investigated. Therefore, the CME's
unknown heating mechanisms have the energy to significantly affect the CME's
eruption and evolution. To understand which parameters might influence the
unknown heating mechanism, we constrain our model heating rates with the
observed data and compare them to the rate of heating generated within a
similar CME that was constructed by the MAS code's 3D MHD simulation. The rate
of heating from the simulated CME agrees with our observationally constrained
heating rates when we assume a quadratic power law to describe a self-similar
CME expansion. Furthermore, the heating rates agree when we apply a heating
parameterization that accounts for the CME flux rope's magnetic energy being
converted directly into thermal energy. This UVCS analysis serves as a case
study for the importance of multi-slit coronagraph spectrometers for CME
studies.
