Analytical expre
ssion
s have been obtained of the main curvature
s of the concavity of the wave vector
surface, corre
sponding to the qua
si-tran
sver
se wave, ver
su
s ani
sotropy parameter
C=
C<
sub>11
sub>−
C<
sub>12
sub>−2
C<
sub>66
sub> of the paratellurite cry
stal. Change
s in the form of the
sound beam on
scanning in the direction of it
s propagation in the (001) and (1
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s have been inve
stigated. It ha
s been found that near the acou
stic axi
s lying in (001) con
siderable tran
sformation of the beam take
s place; initially extended, it become
s squeezed along the [001] axi
s. The condition
s for focu
sing and channelling of ultra
sound radiation have been determined. The propagation direction
s at which ani
sotropy of the paratellurite cry
stal doe
s not influence the beam divergence have been found. It i
s shown that, for a wide range of deviation angle
s θ of the wave normal from the [001] axi
s in the
symmetry plane (1
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sbottom"" border=""0"" height=18 width=12>0) (
θ≤50°), the pre
sence of ani
sotropy lead
s to weaker diffraction broadening. The character of variation in the direction and divergence of the
sound beam on
scanning in the vicinity of the [110] direction ha
s been
studied experimentally.