The invention discloses a
free electron laser device for ultrafast
dynamic imaging and an imaging method, and belongs to the technical field of
free electron laser. The device comprises undulators, four-color magnetic compressors, an
electron beam collector, a transmission
grating and an X-
ray CCD detector which are arranged along an advancing path of an
electron beam, the undulators have different dimensionless
magnetic field parameters K, the four-color magnetic compressors are arranged between every two adjacent undulators, the
electron beam collector is used for collecting the electron beam, and the transmission
grating is used for transmitting the electron beam to the X-
ray CCD detector. The transmission
grating is used for carrying out partial wave
diffraction on the four beams of X-rays penetrating through the sample, and then four
diffraction images are formed on the X-
ray CCD detector. The
undulator has the beneficial effects that the energy of the single-energy electron beam and the parameters of the
undulator can be set to obtain the required X-ray
photon energy, and the
pulse energy is controlled through the number of
undulator modules in combination with an OK mechanism, so that an ultrafast dynamic film of
picosecond-to-
femtosecond-level
time resolution is realized, and the undulator is used for researching an ultrafast dynamic process in a substance.