Plasma heating and relativistic plasma accumulation are realized in the GYRAC-D-O installation. Relativistic plasma accumulation is a result of plasma heating under synchrotron gyromagnetic autoresonance (SGA) and subsequent throwing of the SGA plasma into the central region of the magnetic mirror trap in the regime of the SGA-pulse packet. The optimum of the initial plasma pulsed injection is found. The obtained plasma is e-vortex filled with ions. Major parameters of the plasma are as follows: n = 8 × 109 cm -3: average energy of electrons W=200 keV; lifetime τ=40 ms. The problem of the plasma ejection out of the trap after the accumulation cycle completion is discussed. It is shown that effective plasma ejection and ion acceleration are possible in case of a relatively dense plasma which is feasible only in the accumulation regime.