  The behaviour of electron emission under electron impact at very low energy
is of great importance in many applications such as high energy physics,
satellites, nuclear reactors, etc. However the question of the total electron
reflectivity is still in discussion. Our experimental and theoretical studies
show that the total reflectivity at very low energy is far from being an
obvious fact. Moreover, our results show that the yield is close to zero and
not equal to one for low energy incident electron.
