  It is known that the presence of the Fermi sea modifies the scattering of an
electron from a point-like impurity. This is due to the Friedel oscillations of
the electron density around the impurity. These oscillations create an
additional scattering potential for incident electrons. The closer the energy
of the incident electron to the Fermi level, the stronger the additional
scattering. We study this effect for the case when the impurity is not
point-like but rather a hard disk, with a radius much bigger than the de
Broglie wavelength. We start with a careful examination of the full and
transport cross sections from an extended target. Both cross sections approach
their limiting values upon increasing the wave vector of the incident electron.
We establish that the transport cross section saturates much faster than the
full cross section. With regard to the interaction correction, we establish
that it vanishes for the full cross section, while for the transport cross
section, it is enhanced compared to the case of a point-like scatterer.
