Calorimetric spectrometer for measuring single microwave pulses in relativistic microwave electronics devices

Broadband plasma relativistic microwave oscillators fabricated at the General Physics Institute of the Russian Academy of Sciences have the following output parameters: microwaves are generated in a frequency band on the order of the mean frequency, the output power is -100 MW, the mean microwave frequency is 10-20 GHz, the duration of a single pulse is 20-800 ns, and the diameter of the emitting horn window is no less than 15 cm (because of the possible microwave breakdown). The spectrum of high-power broadband emission from the plasma in the course of a REB-plasma interaction was studied in experiments in a number of experiments but accuracy of measurement has been low. The authors describe a calorimetric spectrometer that has very high accuracy. The main advantage of the spectrometer is that it can measure the spectrum of the total microwave energy flux in absolute units, while the spectrometers used previously were capable of measuring only a small fraction of the total energy flux. The spectrum of the total energy flux from oscillators is the fundamental characteristic calculated theoretically and used to estimate the possible applications.