  Measurements of the order parameter texture of rotating superfluid 3He-B have
been performed as a function of the applied azimuthal counterflow velocity down
to temperatures of 0.2Tc. The results are compared to the hydrostatic theory of
3He-B. Good agreement is found at all measured temperatures and rotation
velocities when the flow anisotropy contribution to the textural free energy is
adjusted. This gives a superfluid energy gap Delta(T) which agrees with that
measured by Todoshchenko et al., with Delta(0)=1.97kBTc at 29.0 bar. The
B-phase susceptibility, longitudinal resonance frequency, and textural phase
transition have been extracted from the measurements as a function of
temperature and azimuthal counterflow velocity. Owing to decreasing absorption
intensities the present measuring method, based on the line shape analysis of
the NMR spectrum, loses its sensitivity with decreasing temperature. However,
we find that in practice the measurement of vortex numbers and counterflow
velocities is still feasible down to 0.2Tc.
