Reflection of Slow Electrons from Solid Surface

Given that progress of future plasma technologies depends on control of electron coefficient reflection $r_{0} $, the development of methods of measurement and control of $r_{0} $is of great importance. Published experimental data on $r_{0} $ for slow electrons are inconsistent and sometime give large values up to $r_{0} \approx 0,8$ and even higher. This talk presents a technique for $r_{0} $ measurements in low pressure plasmas in the presence of transverse magnetic field. It is found that for poly-crystal surface, effective reflection coefficient can really reach value of 0.8. It is demonstrated that it is connected to additional reflection from potential barrier near the surfaces. The contribution of electron reflection from the barrier and the surface has been divided and studied. The data have been confirmed at different mono-crystal surfaces.