ELABORATION OF THE PLASMA-DIELECTRIC WAKEFIELD ACCELERATOR WITH A PROFILED SEQUENCE OF DRIVER ELECTRON BUNCHES

A theoretical and experimental study of wakefield excitation by a profiled sequence of relativistic electron bunches in the plasma-dielectric structure, the parameters of which provide the conditions for the excitation of a small decelerating field for all driver bunches with simultaneous growth with the number of bunches of the accelerating total wakefield was carried out. Theoretically, the transformation ratio was found for the parameters of the experiment as the ratio of the total wakefield of the sequence to the field that decelerates driver bunches. In the performed experiments, the total wakefield was measured by the microwave probe. The magnitude of the decelerating field is determined by the shift of the maximum of the spectrum measured by the magnetic analyzer before and after wakefield excitation in the structure. The obtained transformation ratio increases with the number of bunches in the sequence and significantly exceeds this one for a nonprofiled sequence.