  Recent extension of the topological ideas to continuous systems with broken
time-reversal symmetry, such as magnetized plasmas, provides new insights into
the nature of scattering-free topologically-protected surface plasma waves
(TSPWs). We demonstrate a unique characteristic of TSPWs propagating above the
electron cyclotron frequency: their collisionless damping via coupling to the
continuum of resonant modes localized inside a smooth plasma-vacuum interface.
Damped TSPWs retain their unidirectional nature and robustness against
backscattering. When sheared magnetic field creates a boundary between damped
and undamped TSPWs, the two refract into each other without reflections
