The MILO (Magnetically Insulated Line Oscillator) is a high power microwave source capable of delivering some output powers greater than 1 GW at a frequency of several gigahertz. The device is a crossed electric and magnetic field oscillator without any external structure to establish the static magnetic field required to guide the electron beam. The electrons are emitted by explosive emission from a velvet cathode and accelerated by the electric field in the A–K gap. The anode structure is an electromagnetic cavity which stores some energy, transferred from the electron beam. Thus, the geometry allows the beam to propagate in a magnetic insulation conditi! on and in synchronism between the phase velocity of the electromagnetic slow waves and the drift velocity of the electrons. The aim of this PhD thesis is to review and to study the main characteristics of a compact MILO, when all dimensions are reduced by a factor of 2, in comparison with those in literature, to develop a prototype. All geometrical parameters were included and calculated using the 2D and 3D MAGIC electromagnetic–PIC code. First, we have analysed the cavity–output waveguide coupling and, second the physical factors which reduce the output power. Finally, an optimized modelled tube has led to the construction of an experimental pulsed device in which the preliminary cold tests (without electron beam) have shown a good correlation with the theoretical analysis. This work will be followed by an experimental phase which should demonstrate the merits of our challenge in building a compact MILO source.
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