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A pulsed magnetron system generating high-energy microwave pulses with a frequency of 400 Hz and an average power of 0.5 kW is described. To generate a magnetron current pulse, a circuit with 12 identical transistor modules with an operating voltage of 800 V, which are connected in series to the primary winding of a high-voltage pulse transformer with a transformation ratio of 3.5, is used. Thus, a voltage pulse with an amplitude of up to 26 kV and a 25-A current with an adjustable duration of 100–500 ns is formed. Experimental data of the system operation into the pulsed microwave magnetron and an equivalent load are presented. [ABSTRACT FROM AUTHOR]

A pulsed magnetron system that generates high-energy microwave pulses at a frequency of 100 Hz and an average power of 5 kW is described. A magnetron current pulse is generated using a circuit with 16 identical transistor units with an operating voltage of 800 V, which are connected in series to the primary winding of a high-voltage pulsed transformer with a transformation ratio of 5 during the pulse interval. Thus, a voltage pulse with an amplitude of up to 65 kV, a current of 140 A, and an adjustable duration of 1–6 μs is formed. The experimental data on the operation of the system for a pulsed microwave magnetron and an equivalent load are presented. [ABSTRACT FROM AUTHOR]

Iron nanopowders and iron and aluminum micropowders exposed to microwave radiation with a frequency of 9.4 GHz and a power density of 80 W/cm2 at a pulse repetition rate of 400 Hz have been investigated. According to the results of differential thermal analysis, the microwave radiation caused nonmonotonic changes in the thermal properties of the A1 and Fe powders. After irradiation of the iron nanopowder, the temperature of the onset of its oxidation increased from 150.01 to 158.75°C; in the case of the micropowder, the temperature nonmonotonically changed from 150.00 to 275.38°C. The specific heat of oxidation of the Fe nanopowder increased by 17.3% at maximum, while in the Fe micropowder the maximum attained increase was 13%. For the Al micropowder, the maximum increase in the specific heat of oxidation was found to be 59.7%. Microwave irradiation leads to the formation of electron avalanches, which reduce metal ions in their oxides. At the same time, at certain irradiation doses the generated electron flows oxidize the reduced metals, which is reflected in the nonmonotonic variation in the properties of a material. The increase in the specific heat of oxidation is related to the participation of energy-saturated states of the metals in the oxidation processes. [ABSTRACT FROM AUTHOR]

A generator of high-power Ku-band microwave pulses with resonant pulse compression is described. It allows thestepped control of output-pulse durations from 1 ns to 1.5 μs at a pulse repetition rate of 0.2–1.5 kHz and a peak power of 58 kW to 10 MW. This source can be used for investigating the interaction of electromagnetic radiation with various objects. [ABSTRACT FROM AUTHOR]

An experimental study of a resonance microwave (3-cm-range) compressor with gas insulation and energy output through a superdimensional coaxial interference switch is reported. The rated parameters of the compressor are output signal power ∼25 MW, signal duration 2 ns, gain 26 dB, and efficiency ∼57%. A gain of 20 dB was achieved at a peak output signal power of 12 MW, signal duration of 2 ns, efficiency of ∼24%, and traveling wave power of 24 MW. [ABSTRACT FROM AUTHOR]

It was shown experimentally that the pulse power output of a resonant microwave compressor with an oversized cavity and an interference switch used for energy extraction could be increased using a package of interference switches with summation of the output signals instead of a single switch. The use of two switches for energy extraction provided an almost twofold increase in the output signal power and a corresponding (almost twofold) decrease in the signal duration. It is shown that energy extraction through four switches with signal summation is possible. [ABSTRACT FROM AUTHOR]

It is shown experimentally that in order to increase the stored energy in storage resonators using compressed gas, it is preferable to have oscillation modes in which the electrical components of the fields do not interact with the inner surfaces of the resonator. [ABSTRACT FROM AUTHOR]