Spectral features of stimulated electromagnetic emission, measured in the 4.3-9.5 MHz pump wave frequency range

Steady state spectral features of stimulated electromagnetic emissions (SEE s) for their major emission components (DM, NC, BC, BUM, and BUS) are studi ed in a wide pump wave frequency range, from 4.3 to 9.5 MHz, i.e., from sli ghtly above the 3(rd) to slightly above the 7(th) gyroharmonic frequency. B ased on these systematic experimental data, new peculiarities in the behavi our of the SEE intensity and of the spectral properties, in relation to the gyroharmonic mode number, have been found. The experimental results, discu ssed in the paper, were collected during the years 1996 - 2000 at the Sura heating facility in Russia by modification of the ionospheric F region, usi ng ordinary mode HF pump waves.