Design and Testing of the Photogun Resonator and Biperiodic Accelerating Structure with Traveling Wave for the Photoinjector at the IAP RAS

We present the results of studies aimed at creation of accelerating structures for a photoinjector accelerator that is currently under construction at the IAP RAS. Based on the general theory of coupled oscillators, a simple method for diagnosing the resonant properties of two-cell accelerating structures is given. Electrodynamic measurements of the manufactured photogun at a low power level confirm the ability to achieve the required acceleration gradient, although they show quite a notable difference between its resonant properties and the design. These measurements are in good agreement with analytical estimates and numerical simulations. The project of an additional accelerating structure designed to further accelerate the photoinjector electron bunches up to the energy providing their efficient injection into a wakefield plasma accelerator is also presented.