Klystron type crystal-based x-ray volume free electron laser

Typical parameters of electron bunches available now in undulator x-ray FELs enable generation of induced radiation in crystal-based x-ray volume free electron laser (XVFEL). An important peculiarity of an undulator x-ray FEL is electron bunch spatial modulation matching the radiation wavelength. Therefore, x-ray FEL can be considered as a modulator of electron bunch density. As a result, a facility combining an undulator, which produces a modulated beam, and a crystal, on which the modulated beam is incident, can be considered to be similar to a klystron, which is a well-known source for microwaves emission. The use of a premodulated beam enables to generate and observe superradiation and induced radiation in a crystal-based XVFEL. The number of quanta radiated in a crystal-based XVFEL corresponds (or even exceeds) the number of quanta produced by the XFEL in the same frequency range. Published by the American Physical Society 2024