The operating conditions of an end-fire plasma accelerator with an external magnetic field are studied. Situations arise in which the current is saturated and oscillations are observed at 100-1500 kHz. These oscillations correspond to plasma rotation in the E and H fields. Low-frequency transit-time perturbations are also observed. The limiting ion velocities in the plasma (1-4) multiplied by 10**6 cm/sec are an order of magnitude higher than the velocity obtained in gasdynamic plasma acceleration.