  In cataclysmic variables (CVs), accretion onto white dwarfs produces high
temperature, high density plasmas. They cool down from kT~10 keV via
bremsstrahlung continuum and K and L shell line emissions. The small volume
around white dwarfs means that the plasma densities are much higher than in,
e.g., stellar coronae, probably beyond the range well-described by existing
models. I will describe potential diagnostics of the temperatures, the
densities, and the optical depths of X-ray emitting plasmas in CVs, and present
the recent Chandra grating spectra of the magnetic CV V1223 Sgr as an example.
