Spontaneous Cyclotron Radiation of a Dense Electron Bunch
Short dense electron bunches generated by today’s photoinjectors [1–5] are advantageous for creating powerful sources of spontaneous coherent radiation in the terahertz frequency range. The regime of spontaneous radiation is achieved when the bunch size in the phase space is well below 2π. Coulomb interaction between particles in the dense bunches increases the axial size, and thus can limit the power and duration of radiation. It is shown this problem can be solved for cyclotron radiation by compensating for the Coulomb repulsion in the phase space.