  The geometric structure of an intermediate state in the high pure Gallium
single crys-tal at the external magnetic field Hext at the temperature T=0.4 K
is researched, using the longi-tudinal ultrasonic signal attenuation method at
the ultrasonic signal frequency of 30 MHz. It is experimentally shown that the
edge inhomogeneities of the magnetic field distribution have an influence on
the structure of an intermediate state in the cylindrical superconductor
samples at the transverse orientation of external magnetic field Hext. It is
shown that the use of the super-conducting plane screens of NbZr permits an
approach to the equilibrium intermediate state structure of an infinite
cylinder as confirmed by an experimental dependence of the normal metal layer
thickness aN on the magnitude of external magnetic field aN(Hext) in the high
pure Ga single crystal at an application of the longitudinal ultrasonic signal
with the frequency of 30 MHz at the temperature T=0.4 K. The experimentally
obtained characteristic parameters of an intermediate state structure in the
high pure type I superconductor at the external magnetic field Hext have a
partial qualitative agreement with the Landau theory results.
