  We show that there are restrictions on the maximum tipping angle that can be
used without significantly raising the temperature of the He-3 distribution in
high B/T spin-echo experiments with pure liquid He-3 and He3-He4 solutions. The
temperature increase occurs during the diffusion process as quasiparticles in
mixed-spin states are scattered and converted into thermal excitations at the
spin-up and spin-down Fermi surfaces. This temperature increase can mimic the
effects of zero temperature attenuation, leading to a higher values of the
measured anisotropy temperature T_a. We analyze the dependence of the increase
on polarization, initial temperature, He-3 concentration, and tip angle, and
estimate the size of the effect in recent experiments.
