Beam-density effect on the stopping of fast charged particles in matter

Greatly enhanced stopping powers result from the interaction of sufficiently dense charged particle beams with matter. Stopping power is proportional to a well-defined number of beam particles that interact coherently. The effect is not due to turbulence, but relies on a phase mixing of the polarization wakes produced by the beam particles. The beam-density effect can drive a self-dissipative instability. © 1977 The American Physical Society.