The design and construction of a 6 MeV electron linear accelerator (e-Linac) was defined in the Institute of Nuclear Science and Technology (NSTRI) for cargo inspection and medical applications. For this accelerator, a side coupled standing wave tube resonant at a frequency of 2998.5 MHZ in π/2 mode was selected. In this article, the authors provide a step-by-step explanation of the process of the design for this tube.The design and simulation of the accelerating and coupling cavities were carried out in five steps; (1) separate design of the accelerating and coupling cavities, (2) design of the coupling aperture between the cavities, (3) design of the entire structure for resonance at the nominal frequency, (4) design of the buncher, and (5) design of the power coupling port. At all design stages, in addition to finding the dimensions of the cavity, the impact of construction tolerances and simulation errors on the electromagnetic parameters were investigated. The values obtained for the coupling coefficient, coupling constant, quality factor and capture efficiency are 2.11, 0.011, 16203 and 36%, respectively.The results of beam dynamics study of the simulated tube in ASTRA have yielded a value of 5.14 π-mm-mrad for the horizontal emittance, 5.06 π-mm-mrad for the vertical emittance, 1.17 mm for the horizontal beam size, 1.16 mm for the vertical beam size and 1090 keV for the energy spread of the output beam.

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A: By changing the resonant frequency of the cavity due to the power dissipation in its wall, the impedance matching will impair and the power will reflect. The acceptable frequency shift range which is based on the cooling system in the cavity design depends on the ability of the automatic frequency controller system and the bandwidth of the RF amplifier output frequency. This paper describes how to couple electromagnetic, thermal and mechanical analysis and calculates the cavity frequency shift during operation. Multiphysics analysis investigations had done for an S-band side-coupled cavity. By using the Superfish code, the power loss ratio at different surfaces of the cavity could be accurately calculated and Steady-State Thermal (SST) analysis could be performed correctly. In this paper, the report on the simultaneous use of multiphysics analysis with the modules of the Ansys software is presented and the results of both simulations are compared. The temperature distribution of the cavity was obtained by using the Fluent software and its results were compared with the temperature distribution gained from applying the convection coefficient to the SST. Three cooling systems were investigated for different powers with different cross-sections. In this section of the investigation, after thermal analysis, deformed geometry was obtained due to thermal stresses. By electromagnetic analyzing of deformed geometry, its frequency shift was obtained for all different cases. In order to evaluate the simulations, after the construction of a single-cavity, frequency variations are measured in terms of temperature variation and the results are compared with each other. After constructing a single-cavity, frequency shifts based on temperature variations are measured and the results are compared with each other. K: Acceleration cavities and magnets superconducting (high-temperature superconductor; radiation hardened magnets; normal-conducting; permanent magnet devices; wigglers and undulators); Accelerator modelling and simulations (multi-particle dynamics; single-particle dynamics);

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