This article describes S-band sources of high-power microwave (HPM) pulses: a resonant backward wave oscillator (BWO) producing ∼5-GW, 100-J pulses, based on the SINUS-7 electron accelerator, and a double-section vircator with a peak power of ∼1 GW and a pulse width of 20–50 ns, powered from either the SINUS-7 accelerator or the MARINA inductive-store pulse driver with a fuse opening switch.

A two-section coaxial vircator with radial electron beam injection and electrodynamic feedback was developed. The use of electron beam premodulation in the vircator allows an increase in efficiency and ensures single-mode oscillation. The vircator operates with no external magnetic field, features a comparatively low operating impedance of the vacuum diode (10-15 Ω), and makes feasible wide-band frequency tuning through varying the resonator parameters. The vircator was simulated using the PIC-code KARAT. It is shown that, in a wide range of electron beam power (10-25 GW), the oscillation efficiency is 12%-15% and the frequency tuning bandwidth is 15%. In the experiments on a compact linear transformer driver at a cathode voltage of 300 kV, diode current of 20 kA, and driving pulse duration of 250 ns, the single H 11 mode oscillation at 2.2 GHz with a 300-MW microwave peak power and 130-ns pulse duration at half the power level was realized.

A high-current electron-beam accelerator for pumping of a Xe 2 lamp was developed. It is intended for injection of an electron beam into cylindrical gas cavity (diameter of 400 mm, length of 1600 mm, and the absolute pressure up to 3 bars). Two electron diodes in parallel are used in the accelerator. Each diode is connected to a linear transformer driver with vacuum insulation of a secondary turn. The next parameters of the accelerator have been obtained: diode voltage -550-600 kV, diode current -276-230 kA, current rise time -160 ns, maximum power of the electron beam -130 GW, pulse width on half maximum -160 ns, electron beam energy at power level not less than half of maximum value -20 kJ. The total energy of electrons, which pass through a 40 μm Ti foil into the Xe cell, is 8-9 kJ in the 150-160 ns pulse (full width at half maximum) mean specific power of energy input into gas cavity is about 330 kW/cm 3 . Design of the accelerator and test results are presented and discussed in this paper.

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Linear transformer driver (LTD) technology is actively developed at the Institute of High Current Electronics in Tomsk, Russia. This technology is being examined for use in high current high voltage pulsed accelerators. Recent development of high voltage low inductance capacitors and low inductance switches enabled to achieve ~100 ns rise time of the LTD output pulse. This technique allows one to eliminate intermediate pulse forming sections, used in the present accelerator technology, which would keep the footprint of an LTD accelerator small. LTD based drivers are currently considered for many applications, including future very high current Z-pinch drivers for inertial confinement fusion, medium current drivers with adjustable pulse length for isentropic compression experiments, and finally relatively low current accelerators for radiography and X-pinches. In this article, we present the design and test results for a new LTD stage, that operates at 100 kV charging voltage. Current amplitude up to 850 kA with ~140 ns rise time was obtained on a 0.05 Ω load. Stack of the LTD stages can be easily assembled in series or in parallel, thus providing voltage or current multiplication, respectively. Design of multi-mega-volt and multi-mega-ampere generators becomes straightforward with the LTD technology.