Terahertz-Range Superradiant Generation in the Process of Laser Pulses Scattering with Frequency Down-Conversion

The possibility of generation of THz-range superradiant (SR) pulses by the scattering of a laser pulse on a high-current relativistic electron bunch has been studied. We assume that the laser pulse propagates in the forward direction while scattered radiation has the opposite (backward) direction with respect to an electron bunch. Due to frequency down-conversion, at the optical pumping frequency and moderate electrons energy the frequency of the scattered radiation lies in the THz range. Simulations show that for the electron energy of 2 MeV, SR pulses with the central frequency of 3 THz can be generated. With 3 kJ laser pulses and the intense electron bunches provided by thermo- or photo-cathodes, the peak power of SR pulses can achieve 200 kW with pulse energy exceeding 4 μJ.