Acceleration of electrons at wakefield excitation by a sequence of relativistic electron bunches in dielectric resonator

摘要

Method is proposed to divide a regular sequence of electron bunches into parts of bunches driving wakefield andudwitness bunches, which should be accelerated. It allows to avoid the necessity of additional electron accelerator forudwitness bunches producing and the necessity of precision short time techniques of injection phase adjusting. The ideaudconcludes to the frequency detuning between bunches repetition frequency and the frequency of the fundamental modeudof excited wakefield. Experiments were carried out on the linear resonant accelerator "Almaz-2", which injected in theuddielectric resonator a sequence of 6000 short bunches of relativistic electrons with energy 4.5МeV, charge 0.16 nC andudduration 60psec each, the repetition interval 360 ps. Frequency detuning was entered by change of frequency of theudmaster generator of the klystron within the limits of one percent so that the phase taper on the length of bunchesudsequence achieved 2π. Energy spectra of electrons of bunches sequence, which have been propagated through theuddielectric resonator are measured and analyzed.