The Air Force Research Laboratory RKO source has recently demonstrated
the ability to convert electron beam power to Rf power until the term
ination of the electron beam pulse, achieving a power of 1.5 GW at an
energy of 170 J, These results represent an increase in power of 25-30
% in power and energy extracted from this source. This paper discusses
the principal research areas encountered in lengthening the RF pulse
(FWHM) from 50 ns to the present 120 ns and the associated increase in
the RF energy.