Particle-in-Cell Simulations of High-Power THz Generator Based on the Collision of Strongly Focused Relativistic Electron Beams in Plasma

Based on particle-in-cell simulations, we propose to generate sub-nanosecond pulses of narrowband terahertz radiation with tens MW power using unique properties kiloampere relativistic (2 MeV) electron beams produced by linear induction accelerators. Due small emittance such beams, they can be focused into millimeter and sub-millimeter spots comparable in sizes the wavelength THz radiation. If a beam is injected plasma, it becomes unstable against two-stream instability excites plasma oscillations that converted electromagnetic waves at frequency its harmonics. It shown several mechanisms high efficiency conversion (∼1%) come play when radial size beam–plasma system emitted waves.