THz Partially Coherent Undulator Radiation from the Truncated Electron Bunch

Abstract

The problem of THz coherent undulator radiation from the electron bunch with asymmetric distribution in the longitudinal direction is considered. It is shown that the contribution of coherent part of the total radiation for waves with wavelength much shorter than the characteristic of the longitudinal dimension of the bunch is predominant. It is another way of increasing the efficiency of a free electron laser (FEL).