Design of a linear induction accelerator module for a hybrid antenna-amplifier, a compact controllable high-power microwave source

The system called hybrid antenna-amplifier has been proposed as a combination of a surface wave antenna and a traveling wave tube. In this system, a microwave signal feeding a circular rod antenna would simultaneously serve as the TWT RF drive. The key feature of the concept making the device compact for a high power radiator is that an antenna feed waveguide serves, at the same time, as a cathode holder of a high voltage generator producing a relativistic electron beam. This is possible if a beam is generated by a compact module of a linear induction accelerator. In this work, the possible design of the LIA module for the antenna-amplifier is considered. It is based on the scheme with multi-channel spark gap switching being developed for many years at the NPI. Compactness of the system is provided by using strip pulse forming lines wound around the induction system. The spark gap triggering circuit allows one to synchronize the LIA with a pulsed powerful X-band magnetron to be used as the external RF source. At the accelerator operating parameters required for the antenna-amplifier (250-300 kV, 1.0-1.5 kA) and the power supply providing the rep-rate of up to 50 pps, the LIA dimensions along with the power supply turn out to be about 60 cm diameter and 100 cm length (plus 30-40 cm for the rod structure), and the weight estimation is no more than 500 kg.