The use of dielectric materials in the charged particles accelerators requires investigation of changes in the electrodynamic properties of these materials under the influence of ionizing radiation. First of all it is necessary to study the effect of radiation on the complex dielectric permittivity (ꜫ and tgδ) of these materials. The actual task is to measure very small relative changes in the dielectric constant, for example, ∆ꜫ/ꜫ~10-4. Such accuracy can be provided by resonator methods. In the present work results of theoretical and experimental research of microwave dielectric resonators with open boundaries are given. It is shown, that they can be used to measure dielectrics during irradiation by gamma radiation or charged particles beam. The analysis of factors that affect the accuracy of measurements is carried out.

At the initial stage of acceleration, it is often necessary to create an increasing distribution of accelerating electric field for improving the bunching process. Such distributions can be created by gradually decreasing the coupling coefficients between the resonant volumes. In such bunching structures charged particles are bunched and accelerated by the travelling wave with increasing amplitude. But there is another possibility of creating such increasing distributions. It is well known that in periodic structures there are two different in basis electromagnetic eigen-oscillations supported by metal walls without external currents and charges -propagating and evanescent. In forbidden bands (stopbands) electromagnetic oscillations transfer no energy in the direction of periodicity and have decreasing (increasing) dependence on the longitudinal coordinate. Results of our investigations of the properties of the electromagnetic oscillations in the stopbands of the periodic structures are represented. We discuss the usage of such oscillations in accelerating systems for the bunching and accelerating of electron beams.

No abstract

No abstract

No abstract