Dependence of Plasma Maser Emission Spectra on Azimuthal Plasma Concentration Inhomogeneity

Probe measurements of plasma generated by the thermionic cathode of the axially symmetric plasma maser are performed. Emission spectra of this plasma maser are recorded in its operation mode of a noise amplifier in the frequency band from 3 to 16 GHz at the power level of ~50 MW. It is shown that violation of azimuthal plasma concentration homogeneity leads to broadening of the emission spectrum by 30 to 100% of the central frequency. A possibility is found for pulse-to-pulse electron control of the width of the plasma maser emission spectrum in addition to the electron control of the frequency.