Journal of Statistical Physics, Vol. 117, Nos. 3/4, November 2004. p. 681-702.
Recent numerical simulations indicate that the Lorentz gas with rotating scat-terers yields a good description of transport phenomena. Motivated by this we introduce the rotor interaction in the integrable system of the annulus billiard We prove the presence of a variety of dynamical behavior, from integrability tc ergodicity.