Novel technology of electron beam generation for plasma heating in GOL-3 was developed and for the first time used in the experiment. The distinctive features of the new beam are non-relativistic energy, medium power and sub-ms duration. The experiments were done at the following beam and plasma parameters: ~100 keV, ~10 MW, >100 s, ~1020 m-3. The beam was safely transported through the 13-m-long deuterium-filled multiple-mirror solenoid. The plasma was created and then heated by the beam. Main physical task for the reported experiments was to reach quasi-stationary plasma conditions during the long-pulse beam injection.