Simulations of Cerenkov wake radiation sources

Summary form only given, as follows. The Cerenkov wake stimulated by various excitation schemes (drivers): an intense laser pulse, a train of laser pulses or beats and a relativistic particle bunch in a perpendicularly magnetized plasma are analyzed. In each case the wake generated couples to the electromagnetic radiation of approximate frequency /spl omega//sub p/ at the plasma-vacuum boundary. The radiation amplitude is /spl omega//sub c///spl omega//sub p/ times the amplitude of the wake excited in the plasma (for a sharp boundary). Particle-in-cell simulations are used to verify the scaling laws. Current experiments has resulted in the generation of plasma wakes of the GeV/m order. Given this, the potential for these mechanisms as a possible source of high-power (GW) coherent microwave to terahertz radiation exists. In addition, the Cerenkov radiation provides information about conditions inside the plasma important for plasma accelerators. From the Cerenkov signal, one can infer plasma density, length, plasma wave amplitude and wavelength, and plasma wave lifetime.