The dependence of the generation of upward electron beams in the topside ionosphere on the amplitude of the slow electric field fluctuations and the magnitude of the dc potential difference in the acceleration region is found to agree with the model involving the fluctuating electric field component presented in 1988 by Hultqvist. The ratio between the amplitude of the electric field fluctuations, Ef, determined by the dipole electric field experiment, and the dc acceleration voltage Vacc, given by the energy of the upflowing ion beam, is much higher on average for satellite spins showing an upward electron beam than for the spins without. It is also shown that low plasma density favors the generation of electron beams. ¿American Geophysical Union 1991