  For LCLS-II we estimate the power of radiated wakefields generated in the SRF
cavities (including the 3rd harmonic cavities) and in the end transitions. Much
of this power will pass through and reflect in the strings of cryomodules that
comprise linacs L1, L2, or L3. Presumably, some of it will be absorbed by the
higher order mode (HOM) couplers, or by the absorbers at warmer temperatures
situated between the cryomodules. We investigate where such power gets
generated, but not where it ends up. As such the results can serve as a
pessimistic calculation of the extra power that needs to be removed by the
cryosystem. Finally, we also estimate---under the assumption that all the wake
power ends up in the SRF walls---the wall heating and the extent of Cooper pair
breaking in L3, where the bunch is most intense. Note that all calculations
here are of single bunch effects; thus resonant interactions are not included.
